Father Malebranche his treatise concerning the search after truth The whole work complete. To which is added the author's Treatise of nature and grace: being a consequence of the principles contained in the search. Together with his answer to the animadversions upon the first volume: his defence against the accusations of Monsieur De la Ville, &c. relating to the same subject. All translated by T. Taylor, M.A. late of Magdalen College in Oxford.

THE SECOND PART OF THE SIXTH BOOK, Concerning METHOD.

CHAP. I.

Of the Rules that are to be observed in the Search after Truth.

HAving explain'd the means how to improve the Attention and Extension of the Mind, by which alone it may acquire a greater perfection, that is, become more enlightned, sagaci∣ous and piercing; it is time to set down those Rules, the Observation whereof is abso∣lutely necessary to resolve any Question whatsoever. I shall insist long upon it, and en∣deavour to explain them by several Instances; that their necessity may be better known, and the Mind accustomed to make use of them; it being not so difficult or necessary, to know them theo∣retically, as to put them in Practice.

Let none expect here very extraordinary, surprizing and abstruse things: For on the contrary, that those Rules may be good, they must be very simple, natural and few, very plain and intel∣ligible, and depending on each other; in short, such as may lead our Mind, and rule our Atten∣tion, without distracting either: For Experience shews that the Logick of Aristotle is of no great use, because it takes up the Mind too much, and disturbs the Attention it ought to give to the Subjects of its Enquiry. Let then those Lovers of Mysteries and rare Inventions lay aside for a while that capricious humour, and consider, as attentively as they can, whether the Rules we shall pre∣scribe are sufficient to preserve Evidence in the Preceptions of the Mind, and to discover the most hidden Truths. Unless they suffer themselves to be unjustly prejudiced against those Rules, by the simplicity and easiness of the same, I hope that the great use which may be made of them, as we shall shew hereafter, will convince them, that the most clear and simple Principles are the most pregnant and fecund, and that rare and difficult things are not always so useful as our fruit∣less Curiosity endeavours to persuade us.

The Principle of all those Rules is, that we must always preserve Evidence in our Reasonings, to discover Truth without Fear, and danger of being mistaken. From that Principle follows this general Rule, that respects the Subject of our Studies: We ought only to Reason upon such things, whereof we have clear and distinct Ideas; and by a necessary consequence, we must still begin with the most simple and easie Subjects, and insist long upon them, before we undertake the Enquiry into such as are more composed and difficult.

The Rules that concern the Method to be taken in resolving Questions, depend likewise on the same Principle; and the first of those Rules is, that we must very distinctly conceive the State of the Question proposed to be resolv'd: that is, have Ideas of the Terms so distinct, as that we may com∣pare them together, and discover the Relations which we look for.

When those Relations cannot be found out by an immediate comparison of their Ideas, then the second Rule is, that we must try by an Essay of Thought to discover one, or several intermediate Ideas, that may be a means or common measure to discover the Relations that are betwixt those things. A special care is to be taken that those Ideas be the more clear and distinct, as the Relations we endeavour to discover are more nicely exact and numerous.

When the Questions are very difficult, and require a long Examination, the third Rule is, that we must carefully take off from the Subject to be consider'd, all things whose Examination is not needful to the Discovery of the Truth we are in quest of. For the Capacity of the Mind must not be vainly shar'd and divided, but its strength must only be employed in such things as may en∣lighten it; so that all those things which are to be laid aside, are such as concern not the Questi∣on, and which, when taken off, leave it whole and entire.

When the Question is thus brought within the least compass, the fourth Rule is, to divide the Subject of our Meditations into Parts, and consider them one after the other in a natural order; be∣ginning with the most simple, or those that contain the least number of Relations, and never medling with the more composed, before the most simple are distinctly known, and become familiar.

When they are become familiar by Meditation, the fifth Rule is, to abridge Ideas and dispose them in the Imagination, or write them upon Paper, that they may no longer clog and fill up the Capacity of the Mind. Though that Rule be always useful, yet 'tis not of absolute necessity; un∣less it be in very intricate Questions, that require a great extent of Mind, (for the Mind is only enlarg'd by the abridgment of Ideas). But the use of that Rule and the following, is best known by Algebra.

The Ideas of all the things that necessarily require Examination, being clear, familiar, abridg'd, and disposed and ranged in good order in the Imagination, or written upon Paper, the sixth Rule is, to compare them all by the Rules of Complications, one with the other alternately, either by the View of the Mind alone, or by the Motion of the Imagination, attended with the View of the Mind, or by the Calculation of the Pen joined to the attention of the Mind and Imagination.

If amongst all the Relations that result from those Comparisons, you find not that which you enquire after, then take off again all the Relations that are not subservient to resolve the Question, make the others familiar, abridge them, posture and dispose them in the Imagination, or write them upon Paper, compare them together by the Rules of Complications, and then see whether the composed Relation that is look'd for, is one of the composed Relations that result from those new Com∣parisons.

If none of those new discover'd Relations contain the Solution of the Question, then take off again those that are useless, make the other familiar, &c. [That is, doe the same over and over, and] continuing thus, you shall discover the Truth or Relation you enquire after, how composed soever it may be; provided you can extend the Capacity of your Mind to it, by abridging your Ideas, and still in all your Operations having before your Eyes the Scope you aim at. For 'tis the continual and steady view of the Question which must regulate all the advances of the Mind; since we should always know whither we are going.

We must above all take care not to satisfie our selves with some glimpse or likelyhood; but begin anew so often the Comparisons that are conducible to discover the Truths enquired after, as that we may not withold our Assent to it, without feeling the secret Lashes and Reproofs of our internal Master that Answers our Questions, that is, the Application of our Mind, and the De∣sires of our Heart. Then will that Truth serve as an infallible Principle, to proceed in the Ac∣quisition of Sciences.

All the Rules we have given are not necessary in all sorts of Questions: for the first Rule is suf∣ficient in those that are easie: and we need but in some others the first and second. In short, since we must make use of those Rules, 'till we have discover'd the Truth we seek for; it follows, that the more difficult the Questions are, the greater must the number of those Rules be which we must put in practice.

Those Rules are not very numerous, but very natural, as depending upon each other, and may be made so familiar as to fall of themselves into the Mind, as often as shall be requisite. In short, they can rule the Attention of the Mind without dividing it, which is in great part what we could desire; but they look so inconsiderable in themselves, that to make them more recommendable, it is necessary to shew that the Philosophers are fallen into a great many Errours, and Extrava∣gancies, by not observing so much as the two first, which are the chief and easiest of all; whereas Des Cartes, by their use, has discover'd all those great and fruitful Truths, which are to be learn'd in his Works.

CHAP. II.

Of the general Rule that concerns the Subject of our Studies: That School-Philosophers observe it not, which is the Cause of several Errours in their Physicks.

THE first of these Rules, and which respects the Subject of our Studies, teaches, that we must not argue, except from clear Ideas; whence it follows, that to study methodically, we must begin with things most simple and easie to be understood, and insist long upon them, before we undertake to enquire after the more composed and difficult.

Every one will easily grant the necessity of that general Rule; plainly seeing, that he walks in the dark, who reasons upon obscure Ideas, and uncertain Principles. But 'twill be matter of sur∣prize to hear us affirm, that it is hardly ever observed; and that the greatest part of those Scien∣ces, which still at this day flush the Pride of some false Pretenders to Science, are only grounded upon such Ideas, as are either too confused, or too general, to be conducible to the finding out of Truth.

Aristotle, who so justly deserves the Quality of Prince of such Philosophers, (as being the Fa∣ther of that Philosophy which they so studiously cultivate,) reasons very seldom upon other Ideas, than such as are confused and sensible, and upon others that are general, undetermin'd, and repre∣senting nothing particular to the Mind. For the ordinary Expressions of that Philosopher are so perplexed, as to represent only to the Senses and Imagination, the confused Sentiments we have of sensible things; or to make his Disciples speak in such a rambling and indeterminate manner,

as not to understand themselves. Most of his Works, but especially his Eight Books of Physicks, on which are as many different Commentators as there are Professors of Philosophy, are a mere Logical Tattle, where he talks much, and says nothing: Not that his Stile is too copious and diffused, but because he has a particular Talent at being succinct, and saying nothing but Words. In his other Works he makes not such frequent use of his loose and general Terms; but those he employs raise only the confused Ideas of the Senses; by which Ideas he pretends, in his Problems, and elsewhere, to resolve in two Words an infinite Number of Questions, of which it may be de∣monstrated that they are altogether insoluble.

But that my Meaning may be better understood, what I have proved in other Places must here be remembred, viz. That all the Terms that excite nothing but sensible Ideas, are equivocal; nay, and what's to be well observ'd, Equivocal from Errour and Ignorance, which must needs cause an infinite number of Delusions.

The Word Ram is equivocal, signifying an Animal that ruminates, and a Constellation into which the Sun enters at Spring; but that seldom causes any Mistake: For he must be an Astrologer with a Witness, who should imagine any Relation betwixt those two Things, and believe, for in∣stance, that we are subject at that time to vomit up the Medicines that we take, because the Ram is a ruminating Beast. But as to the Terms of sensible Ideas, but few acknowledge them for Equivocal. Aristotle and the Ancient Philosophers did not so much as dream on't; which will be agreed to by any one that has read any of their Books, and distinctly knows the Cause why those Words are liable to Equivocation. For nothing is more evident, than that the Philosophers Opi∣nion, as to that Matter, was quite contrary to the Truth.

For instance: When they say, that Fire is hot, Grass green, Sugar sweet; they understand, just as Children, and the vulgar of Men, that Fire contains in it what they feel when they warm them∣selves; that Grass has painted upon it the Colours they see; that Sugar is endued with that Sweetness they taste when they eat it; and so as to all other visible and sensible Qualities; which cannot be denied by those that have read their Writings. They talk of sensible Qualities as of Sensations; they take Heat for Motion. And thus, by the Equivocation of Terms, they confound the Modes of Existence peculiar to Bodies, with the Modifications of the Soul.

'Tis no longer since than Des Cartes's time, that to those confused and indeterminate Questi∣ons, Whether Fire is hot, Grass green, and Sugar sweet, &c. we use to answer by distinguish∣ing the Equivocation of sensible Terms that express them. If by Heat, Colour, and Savour, you understand such and such Dispositions of Parts, or Motion of insensible Particles, then Fire is hot, Grass green, and Sugar sweet. But if by Heat, and other Qualities, you understand what I feel when near the Fire, what I see when I see Grass, &c. Fire is not hot, nor Grass green, &c. For the Heat I feel, and the Colours I see, are only in the Soul, as has been proved in the First Book. But as Men commonly suppose, that what they feel is the same with that which is in the Object; so they believe they are in the right, when they judge of the Qualities of Objects by their own Sensations: And thus they hardly say two Words without speaking a Falsehood, and never say any thing upon that Matter, but what is obscure and confused; and that for the several following Reasons.

First, Because all Men have not the same Sensations of the same Objects, nor even the same Man in different Times, or when different Parts of his Body are affected by them. What is sweet to one, is bitter to another; what is hot to one, is cold to another; what seems hot to a Man when he is cold, feels cold to himself when he is hot, or when other Parts of his Body are affected. Water, that feels warm to the Hands, will seem cold if we wash with it any Part near the Heart. Salt, that is savoury to the Tongue, is pricking and smarting to a Wound. Su∣gar is sweet, and Aloes very bitter to the Tongue; but nothing is either sweet or bitter to the other Senses: So that when we say, a Thing is cold, sweet, bitter, &c. that same has no certain Signification.

Secondly, Because different Objects can cause the same Sensation. Plaister, Bread, Snow, Su∣gar, Salt, &c. are of the same Colour; and yet their Whiteness is different, if we judge of 'em otherwise than by the Senses: And therefore when we say, that Meal is white, we say not any thing distinctly significative.

The third Reason is, Because such Qualities of Bodies as occasion Sensations altogether diffe∣rent, are however almost the same; whereas such as excite very near the same Sensation, are often very different. The Qualities of Sweetness and Bitterness differ but little in Objects; whereas the Sense of Sweet essentially differs from that of Bitter. The Motions that cause Smart and Tickling, differ but in more or less; and yet the Sensations of Tickling and Smart are essentially different. On the contrary, the Sharpness of Fruit differs not so much from Bitterness, as Sweet∣ness does; however, that sharp Quality is the farthest from Bitterness that possibly can be: For, a Fruit that is sharp for being unripe, must undergo a great many Changes, before it grows bitter from Rottenness, or too much Ripeness. When Fruits are ripe, they taste sweet; and bitter, when over-ripe: Bitterness and Sweetness therefore in Fruits differ but in degree of more and less; which may be the Reason why they seem sweet to some Persons, whilst they taste bitter to others: Nay, there are those to whom Aloes seem as sweet as Honey. The same may be said of all sensible Ideas; so that the Words Sweet, Bitter, Salt, Sowre, Acid, &c. Red, Green, Yellow, &c. of such and such a Smell, Savour, Colour, &c. are all equivocal, and raise no clear and distinct Idea in the Mind. However, School-Philosophers, and the vulgar part of Men, judge of all the sensible Qualities of Bodies by the Sensations they receive from them.

Nor do the Philosophers only judge of these sensible Qualities by their own Sensations of them; but also judge of the Things themselves, from the Judgments they have pass'd about sen∣sible Qualities: For, from their having had Sensations of certain Qualities essentially different, they judge that there is a Generation of new Forms, producing those fantastick Differences. Wheat appears yellow, hard, &c. Meal, white, soft, &c. Thence, upon the Testimony of their Eyes and Hands, they infer, That those Bodies are essentially different, unless they chance to think on the Manner of the Transmutation of Wheat into Flower: For Meal is nothing but bruised and ground Corn; as Fire is only divided and agitated Wood; as Ashes are but the grossest Parts of the divided Wood without Agitation; as Glass is but Ashes, whose Particles have been polished and rounded by the Attrition caus'd by the Fire: And so in other Transmutations of Bodies.

'Tis therefore evident, that sensible Words and Ideas are altogether unserviceable to a just sta∣ting, and clear resolving of Questions; that is, to the Discovery of Truth. Yet there are no Que∣stions, how intricate soever they may be, by the equivocal Terms of the Senses, but Aristotle, and most part of other Philosophers, pretend to resolve them in their Books, without the forego∣ing Distinctions, and without considering that they are equivocal by Errour and Ignorance.

If, for example, those Persons who have employed the best part of their Life in reading Anci∣ent Philosophers and Physicians, and have wholly imbib'd their Spirit and Opinions, are ask'd whether Water be wet, whether Fire be dry, Wine hot, the Blood of Fishes cold, Water rawer than Wine, Gold perfecter than Mercury; whether Plants and Beasts have Souls; and a thousand like undetermin'd Questions; they rashly answer, by consulting only the Impressions of Objects upon their Senses, or the Tracks the reading of Authors has left upon their Memory. They never think those Terms are equivocal; 'tis a Wonder to them they should need a Defini∣tion; and they cannot endure those that endeavour to let 'em understand, that their Procedure is too quick, and that they are seduced by their Senses; and though they are never at a loss for Distinctions to perplex the most evident Things, yet in these Questions, in which Equivocation needs so much to be removed, they find nothing to distinguish.

If we consider, that most of the Questions of Philosophers and Physicians contain some equi∣vocal Terms, like to those that have been spoken of; we shall not doubt, but that those Learned Gentlemen, that could not define them, were unable to say any Thing solid and real, in the bulky Volumes they have compos'd: Which is, in a manner, sufficient to overthrow most of the Opi∣nions of the Ancients. It is not so with Des Cartes; he perfectly knew how to distinguish those Things: He ne'er resolves any Question by sensible Ideas; and whoever shall be at the pains to read him, shall see, that he clearly, evidently, and almost ever demonstratively, explains the chief Operations of Nature by the sole and distinct Ideas of Extension, Figures, and Motion.

The second sort of equivocal Words, that is much in request amongst Philosophers, contains all those general Terms of Logick by which any Thing may be easily explain'd, without so much as knowing it. Aristotle was the Man that made the most of it; his Books are full of nothing else, and some are but a mere Logick: He proposes and resolves all Things by the specious Words of Genus, Species, Act, Power, Nature, Form, Faculty, Quality, Causa per se, Causa per acci∣dens: His Followers can hardly understand that those Words signifie Nothing, and that one is not more learned than he was, when he has heard, that Fire dissolves Metals by its dissolving Faculty; that a Man digests not, because his Stomach is weak, or because his Concoctive Faculty does not operate as it should do.

I grant, that those who use such general Terms and Ideas for the Explication of all Things, commonly fall not into so many Errours, as those that only employ such Words as raise the con∣fused Ideas of the Senses. The School-Philosophers are not so liable to be deceived, as some opinionative and dogmatical Physicians, who build Systems upon Experiments, the Reasons of which are unknown to them; because the School-men talk so generally, that they do not venture much out of their Depth.

Fire heats, dries, hardens, and softens, because it has the Faculty of producing those Effects: Sena purges by its purgative Quality: Bread nourishes by its nutritious Quality. These Proposi∣tions are not liable to mistake; for a Quality is that which denominates a Thing by such a Name; Master Aristotle's Definition is undeniable: But he speaks true only because he says no∣thing; and if his rambling, loose, and indefinite Notions engage not into Errour, at least they are wholly unserviceable to the Discovery of Truth.

For, though we know that there is in Fire a substantial Form, attended with a Million of Fa∣culties, like to that of heating, dilating, melting Gold, Silver, and other Metals, lightening, burning, roasting; the Idea of that substantial Form, with all its Faculties of producing Heat, Fluidity, Rarefaction, will not help me to resolve this Question, Why Fire hardens Clay, and sof∣tens Wax? There being no Connection betwixt the Ideas of Hardness in Clay and Softness in Wax, and those of a substantial Form in Fire, and its Faculties of Rarefaction, Fluidity, &c. The same may be said of all general Ideas; which are utterly insufficient for resolving any Question.

But when I know that Fire is nothing else but divided Wood, whose Parts are in a continual Agitation, by which alone it raises in me the Sensation of Heat; and that the Softness of Clay consists in a Mixture of Water and Earth; those Ideas being not general and confused, but par∣ticular and distinct, it will not be difficult to perceive that the Heat of Fire must harden Clay, nothing being easier to conceive, than that one Body may move another, if it meet with it, being it self in Motion. We likewise easily perceive, that since the Heat we feel near the Fire is caused

by the Motion of the invisible Particles of Wood striking against our Hands, Face, &c. if we ex∣pose Clay to the Heat of Fire, the Particles of Water, that are mixed with those of Earth, be∣ing more thin and disunited, and consequently more agitated by the Action and Impulse of the fiety Corpuscles, than the gross Particles of Earth, must be separated and expelled, and the other remain dry and hard. We shall perceive with the same Evidence, that Fire must produce a quite contrary Effect upon Wax, if we know that it is composed of Particles that are branched, and almost of the same Bulk. Thus may particular Ideas be subservient to the Enquiry after Truth, whilst loose and undeterminate Notions are not only altogether unserviceable, but also insensibly engage us into Errour.

For, these Philosophers are not content to make use of those general Terms, and uncertain Ideas which answer to them; they moreover pretend, that those Words signifie some particular Beings; they give out, that there is a Substance distinguished from Matter, which is the Form of it; and withal, an infinite Number of little Beings, really distinguished from that Matter and Form, of which they suppose as many as they have different Sensations of Bodies, or as those Bodies are supposed to produce different Effects.

However, 'tis visible to any attentive Person, that those little Beings, for instance, that are said to be distinguished from Fire, and suppos'd to be contained in it for the producing Heat, Light, Hardness, Fluidity, &c. are but the Contrivances of the Imagination, that rebells against Reason; since Reason has no particular Idea that represents those little Beings. When the Philo∣sophers are asked, What is the illuminating Faculty in Fire? They only answer, That 'tis a Be∣ing which is the Cause that Fire is capable of producing Light. So that their Idea of that illu∣minating Faculty differs not from the general Idea of Cause, and the confused Idea of the Effect they see; and therefore they have no clear Idea of what they say, when they admit those parti∣cular Beings; and so say what they not only understand not, but what's impossible to be under∣stood.

CHAP. III.

Of the most dangerous Errour in the Philosophy of the Ancients.

PHilosophers not only speak without understanding themselves, when they explain the Effects of Nature by some Beings of which they have no particular Idea; but also establish a Prin∣ciple whence very false and pernicious Consequences may directly be drawn.

For, supposing with them, that there are in Bodies certain Entities distinguished from Matter, and having no distinct Idea of those Entities; 'tis easie to imagine, that they are the real or prin∣cipal Causes of the Effects we see. And this is the very Opinion of the vulgar Philosophers. The prime Reason of their supposing those substantial Forms, real Qualities, and other such like Entities, is, to explain the Effects of Nature: But when we come attentively to consider the Idea we have of Cause or Power of acting, we cannot doubt but that it represents something Di∣vine: For, the Idea of a Sovereign Power is the Idea of a Sovereign Divinity; and the Idea of a subordinate Power, the Idea of an inferiour Divinity, yet a true Divinity; at least, according to the Opinion of the Heathens, supposing it to be the Idea of a true Power or Cause. And there∣fore we admit something Divine in all the Bodies that surround us, when we acknowledge Forms, Faculties, Qualities, Virtues, and real Beings that are capable of producing some Effects by the force of their Nature; and thus insensibly approve of the Sentiments of the Heathens, by too great a Deference for their Philosophy. Faith indeed corrects us; but it may perhaps be said, that the Mind is a Pagan, whilst the Heart is a Christian.

Moreover, it is a hard Matter to persuade our selves, that we ought neither to fear nor love true Powers and Beings, that can act upon us, punish us with some Pain, or reward us with some Pleasure. And as Love and Fear are a true Adoration, it is hard again to imagine why they must not be ador'd: For, whatever can act upon us as a true and real Cause, is necessarily above us, according to Reason and St. Austin; and, by the same Reason and Authority, 'tis likewise an immutable Law, That inferiour Beings should be subservient to superiour: Whence that great Fa∣ther concludes, That the Body cannot operate upon the Soul , and that nothing can be above her but God only.

The chief Reasons that God Almighty uses in the Holy Scriptures, to prove to the Israelites, that they ought to adore, that is, to love and fear him, are drawn from his Power to reward or pu∣nish them; representing to them the Benefits they have received from him, the Punishments he has inflicted upon them, and his Power that is always the same. He forbids them to adore the Gods of the Heathens, as such as have no Power over them, and can doe them neither harm nor good. He commands them to honour him alone, as the only true Cause of Good and Evil, Reward and Pu∣nishment; none of which can befal a City, according to the Prophet, but what comes from him, by reason that natural Causes are not the true Causes of the Hurt they seem to doe us; and as it is God alone that acts in them, so 'tis He alone that must be fear'd and lov'd in them: Soli Deo Honor & Gloria.

Lastly, The Sense of fearing and Loving what may be the true Cause of Good and Evil, appears so natural and just, that it is not possible to cast it off. So that in that false Supposition of the Philosophers, which we are here endeavouring to destroy, that the surrounding Bodies are the true Causes of our Pain and Pleasure; Reason seems to justifie a Religion like the Pagan Idola∣try, and approve the universal Depravation of Morals.

Reason I grant, teaches not, to adore Onions and Leeks, for instance, as the Sovereign Divi∣nity; because they can never make us altogether happy when we have them, or unhappy when we want them: neither did the Heathens worship them with an equal Homage as their great Jupiter, whom they fansied to be the God of Gods; or as the Sun, whom our Senses represent as the universal Cause, that gives Life and Motion to all things, and which we can hardly forbear to look on as the Sovereign Divinity, if we suppose, as the Pagan Philosophers, that he Compre∣hends in his Being, the true Causes of what he seems to produce, as well upon our Soul and Bo∣dy, as upon all the Beings that surround us.

But if we must not pay a Sovereign Worship to Leeks and Onions, they deserve, at least, some particular Adoration; I mean they may be thought upon and loved in some manner, if it be true, that they can in some sort make us happy, and may be honour'd proportionably to the good they doe us. Surely Men that listen to the Reports of Sense, think Pulse capable of doing them good; otherwise the Israelites would not have bewailed the loss of them in the Wilderness, or look'd on themselves as unhappy, for being deprived thereof, had they not fansied to themselves some great Happiness in the Enjoyment of them. See what an Abyss of Corruption Reason plunges us into, when it goes hand in hand with the Principles of Pagan Philosophy, and follows the foot∣steps of the Senses.

But that the Falshood of that wretched Phylosophy, and the Certainty of our Principles, and Distinctness of our Ideas may not be longer doubted; it will be necessary plainly to establish the Truths that contradict the Errours of the Ancient Philosophers, or to prove in few words, that there is but one true Cause, since there is but one true God; that the Nature and Force of every thing is nothing but the Will of God; that all Natural things are not real, but only occasional Causes; and some other Truths depending on them.

It is evident, that all Bodies, great and little, have no force to move themselves: a Mountain, a House, a Stone, a Grain of Sand, the minutest and bulkiest Bodies imaginable, are alike as to that. We have but two sorts of Ideas, viz. of Spirits and Bodies; and as we ought not to speak what we conceive not, so we must only argue from those two Ideas. Since therefore our Idea of Bodies, convinces us that they cannot move themselves, we must conclude that they are mo∣ved by Spirits. But considering our Idea of finite Spirits, we see no necessary Connexion betwixt their Will, and the Motion of any Body whatsoever; on the contrary, we perceive that there is not nor can be any. Whence we must infer, if we will follow Light and Reason, That as no Body can move it self, so no Created Spirit can be the true and principal Cause of its Motion.

But when we think on the Idea of God, or of a Being infinitely perfect, and consequently Almighty, we are aware that there is such a Connexion betwixt his Will and the Motion of all Bodies, that it is impossible to conceive he should will that a Body be moved, and it should not be moved. And therefore if we would speak according to our Conceptions, and not according to our Sensations, we must say that nothing but his Will can move Bodies. The moving force of Bodies is not then in themselves, this force being nothing but the Will of God: Bodies then have no proper Action, and when a moving Ball meets with another, and moves it, the former communicates nothing of its own to the latter, as not having in it self the Impression it com∣municates; though the former be the Natural Cause of the latter's Motion; and therefore a na∣tural Cause is not a true and real Cause, but only an occasional; which in such or such a Case de∣termines the Author of Nature to act in such or such a manner.

'Tis certain that all things are produced by the Motion of visible or invisible Bodies; for Ex∣perience teaches us, that those Bodies, whose parts are in greater Motion, are always the most active, and those that Cause the greatest Alterations in the World: so that all the Forces of Na∣ture are but the Will of God, who Created the World; because he will'd it, who spake and it was done ; who moves all things, and produces all the Effects we see, because he has established some Laws, by which Bodies Communicate their Motion to each other when they meet toge∣ther; and because those Laws are efficacious, they and not the Bodies act. There is then no Force, Power, nor true Cause in all the Material and sensible World: Nor need we admit any Forms, Faculties, or real Qualities to produce Effects, which the Bodies bring not forth, or to di∣vide with God his own Essential Force and Power.

As Bodies cannot be the true Causes of any thing; so likewise the most Noble Spirits are sub∣ject to the same impotency on that respect: They cannot know any thing, unless God enlightens them; nor have the Sensation of any thing, unless he modifies them; nor will, unless he moves them towards himself: They may indeed determine the Impression God has given them to him∣self, towards other Objects; but I doubt whether it can be call'd a Power. For if to be able to sin is a Power, it is such a one, as the Almighty wants, saith St. Austin somewhere. If Men had of themselves the Power of loving Good, it might be said that they have some Power; but they cannot so much as love, but because God Wills it, and that his Will is Efficacious. They love, because God continually drives them towards Good in general, that is, towards himself, for whom alone they are Created and preserved. God moves them, and not themselves, towards Good in general: and they only follow that Impression by a free Choice, according to the Law of God,

or determine it towards false and seeming Goods, according to the Law of the Flesh; But they cannot determine it but by the sight of Good. For being able to doe nothing without an Im∣pression from above, they are incapable of loving any thing but Good.

But though it should be supposed, which is true in one sense, that Spirits have in themselves the Power of knowing Truths, and loving Good; should their Thoughts and Will produce no∣thing outwardly, it might still be said, that they were impotent and unoperative. Now it seems undeniable, that the Will of Spirits is not able to move the smallest Body in the World; it being evident there is no necessary Connexion betwixt the Will we may have of moving our Arm, for instance, and the Motion of the same Arm. It moves indeed whenever we will it, and we may be call'd, in that sense, the natural cause of the Motion of our Arm; yet natural Causes are not true, but only occasional, as acting by the mere force and efficacy of the Will of God, as we have already explain'd.

For how is it possible for us to move our Arm? To perform this, 'tis requir'd we should have Animal Spirits, and send them through certain Nerves towards certain Muscles, to swell up and contract them, for so that Motion is perform'd, as some pretend, though others deny it, and as∣sert that the Mystery is not yet discover'd. However it be, most Men know not so much as that they have Spirits, Nerves and Muscles, and yet move their Arms with as much and more dexte∣rity than the most skilful Anatomists. Men therefore will the moving their Arm, but 'tis God that is able, and knows how to doe it. If a Man cannot overthrow a Tower, yet he knows what must be done to effect it: but not one amongst them knows what the Animal Spirits must doe to move one of his Fingers. How should they then move the whole Arm of themselves? These things appear very evident to me, and, I suppose, to all thinking Persons; though they may be incomprehensible to others, such as are only used to the confused voice of the Senses.

But Men are so far from being the true Causes of the Motions produc'd in their Body, that it seems to imply a Contradiction they should be so. For a true Cause is that betwixt which and its Effect, the Mind percieves a necessary connexion; for so I understand it. But there is none be∣sides the infinitely perfect Being, betwixt whose Will and the Effects the Mind can perceive a necessary Connexion; and therefore none but God is the true Cause, or has a real Power of mo∣ving Bodies. Nay, it seems unconceivable, that God should communicate this Power, either to Angels or Men: And those that pretend that the Power we have of moving our Arm is a true Power, must by Consequence grant that God can give Spirits the Power of creating, annihilating, and doing all possible things; in short, that he can make them Almighty, as I am going to pove.

God needs not Instruments to act, 'tis enough he should Will the Existence of a thing, in or∣der to its Existing; because it is contradictory that he should will a thing, and his Will should not be fulfilled. And therefore his Power is his Will, and to communicate his Power is to com∣municate his Will; so that to communicate his Will to a Man or an Angel, can signifie nothing else, but to will that whenever that Man or Angel shall desire that such or such a Body be moved, it may actually be moved. In which Case I see two Wills concurring together, that of God, and that of the Angel, and to know which of them is the true Cause of the Motion of that Body, I enquire which is the Efficacious. I see a necessary Connexion betwixt the Will of God, and the thing willed; in this Case God wills that whenever the Angel shall desire that such a Body be moved, it be really so. There is then a necessary Connexion betwixt the Will of God, and the Motion of that Body, and consequently God is the true Cause of that Motion, and the Will of the Angel is only occasional.

Again, to make it more evidently manifest, let us suppose God wills it should happen quite contrary to the Desire of some Spirits, as may be thought of the Devils, or some other wicked Spirits in Punishment of their Sins. In that Case it cannot be said God communicates his Power to them; since nothing happens of what they wish. However the Will of those Spirits shall be the natural Cause of the produced Effects: as such a Body shall be removed to the Right, be∣cause they wish it were moved to the Left; and the Desires of those Spirits shall determine the Will of God to act, as the Will of moving the Parts of our Body, determine the first Cause to move them; and therefore the Desires of all finite Spirits are but occasional Causes.

If, after all these Reasons, it be still asserted, that the Will of an Angel moving a Body is a true, and not a bare occasional Cause; 'tis evident, that the self-same Angel might be the true Cause of the Creation and Annihilation of all things, since God might as well communicate to him his Power of Creating, and annihilating Bodies, as that of moving them, if He should will that they should be created, and annihilated: in a word, if he will'd that all things should be per∣formed according to the Angel's Desires, as he wills that Bodies be moved as the Angel pleases; if therefore it may be said, that an Angel or Man are true Movers, because God moves Bodies as they desire; that Man or Angel might likewise be call'd true Creatours, since God might cre∣ate Beings on occasion of their Will: Nay, perhaps it might be said, that the vilest of Animals, or even mere Matter, is the real Cause of the Creation of some Substance; if it be supposed with some Philosophers, that God produces substantial Forms, whenever the Disposition of Matter re∣quires it. And lastly, since God has resolved from all Eternity, to create some certain things, at some certain times; those Times might also be called the Causes of the Creation of such Be∣ings; with as much right as 'tis pretended, that a Ball meeting with another is the true Cause of the Motion that is communicated to it; because God, by his general Will, that constitutes the Order of Nature, has decreed, that such or such Communication of Motions should follow up∣on the Concourse of two Bodies.

There is then but one true Cause, as there is one true God: Neither must we imagine, that what precedes an Effect does really produce it. God himself cannot communicate his Power to Crea∣tures according to the Light of Reason; He cannot make them true Causes, and change them in∣to Gods. But though he might doe it, we conceive not why he should will it. Bodies, Spirits, pure Intelligences, all can doe nothing. 'Tis he who has made Spirits, that enlightens and moves them; 'tis he who has created Heaven and Earth, that regulates all their Motions: In fine, 'tis the Authour of our Being that performs our Desires; Semel jussit, semper paret: He moves even our Arms, when we use them against his Orders; for he complains by his Prophets, That we make him subservient to our unjust and criminal Desires.

All those little Divinities of the Heathens, all those particular Causes of Philosophers, are Chi∣meras, which the wicked Spirit endeavours to set up, that he may destroy the Worship of the true God. The Philosophy we have received from Adam, teaches us no such things; but that which has been propagated by the Serpent; for, ever since the Fall, the Mind of Man is turned Heathen. That Philosophy, join'd to the Errours of the Senses, has made Men pay their Wor∣ship to the Sun, and is still the universal Cause of the Disorders of their Mind, and the Corrup∣tion of their Heart. Why, say they, by their Actions, and sometimes by their Words, should we not love Bodies, since they are able to afford us Pleasure? And why are the Israelites blam'd for lamenting the Loss of the Garlick and Onions of Egypt, since the Privation of those things, which enjoyed, afforded them some Happiness, made them in some sort unhappy? But the Philosophy that is mis-call'd New, and represented as a Bugbear to frighten weak Minds; that is despised and condemned without hearing: that New Philsosophy, I say, (since it must have that name,) destroys all the Pretences of the Libertines, by the establishing its very first Principle that per∣fectly agrees with the first Principle of the Christian Religion , namely, That we must love and fear none but God, since none but He alone can make us happy.

As Religion declares that there is but one true God, so this Philosophy shews that there is but one true Cause. As Religion teaches that all the Heathen Divinities are but dead Metals, and immovable Stone; so this Philosophy discovers, that all the second Causes, or Divinities of the Philosophers, are but unactive Matter, and ineffective Wills. As Religion commands, not to bow to those Gods that are not Gods, so this Philosophy teaches, not to prostrate our Minds and Ima∣gination before the phantastick Grandeur and Power of pretended Causes, which are not Causes: which we ought neither to love, nor to fear, nor be taken up with; but think upon God alone, see and adore, love and fear him in all things.

But that's not the Inclination of some Philosophers; they will neither see God, nor think upon him; for ever since the Fall there is a secret Opposition betwixt God and Man. They delight in Gods of their own Invention; in loving and fearing the Contrivances of their Heart, as the Hea∣thens did the Works of their Hands. They are like those Children, who tremble at the sight of their Play-Fellows, after they have dawb'd and blacken'd them. Or, if they desire a more noble Comparison, though perhaps not so just, they resemble those famous Romans, who reverenced the Fictions of their Mind, and foolishly adored their Emperours, after they themselves had let loose the Eagle at their Canonization.

CHAP. IV.

An Explication of the Second Part of the General Rule: That the Philo∣sophers observe it not, but that Des Cartes has exactly followed it.

WE have been shewing to what Errours Men are liable, when they reason upon the false and confused Ideas of the Senses, and their rambling and undetermin'd Notions of Lo∣gick; whence it appears, that to keep to Evidence in our Perceptions, 'tis absolutely necessary exactly to observe that Rule we have prescrib'd; and to examine which are the clear and distinct Ideas of things, that we may only argue by deduction from them.

In that same general Rule, concerning the Subject of our Studies, there is yet a remarkable Circumstance; namely, That we must still begin with the most simple and easie things, and in∣sist long upon them, before we undertake the Enquiry after the more composed and difficult. For if, to preserve Evidence in all our Perceptions, we must only reason upon distinct Ideas, 'tis plain that we must never meddle with the Enquiry of compound things, before the simple, on which they depend, have been carefully examin'd, and made familiar to us by a nice Scrutiny; since the Ideas of compound things, neither are, nor can be clear, as long as the most simple, of which they are composed, are but confusedly and imperfectly known.

We know things imperfectly, when we are not sure to have considered all their Parts: and we know them confusedly, when they are not familiar enough to the Mind, though we may be cer∣tain of having consider'd all their Parts. When we know them but imperfectly, our Argumen∣tations are only probable: when we perceive them confusedly, there is neither Order not Light

in our Inferences; and often we know not where we are, or whither we are going: But when we know them both imperfectly and confusedly, which is the commonest of all, we know not so much as what we would look for, much less by what Means we are to find it: So that it is al∣together necessary to keep strictly to that Order in our Studies, Of still beginning by the most simple Things, examining all their Parts, and being well acquainted with them, before we meddle with the more composed, that depend on the former.

But that Rule agrees not with the Inclination of Man, who naturally despises whatever ap∣pears easie; his Mind being made for an unlimited Object, and almost incomprehensible, cannto make a long Stay on the Consideration of those simple Ideas, which want the Character of Infi∣nite, for which he is created. On the contrary, and for the same Reason, he has much Venera∣tion, and an eager Passion, for great, obscure, and mysterious Things, and such as participate of Infinity: Not that he loves Darkness; but that he hopes to find in those deep Recesses a Good, and Truth capable of satisfying his Desires.

Vanity likewise gives a great Commotion to the Spirits, stirring them to what is great and ex∣traordinary, and encouraging them with a foolish Hope of hitting right. Experience teaches, that the most accurate Knowledge of ordinary Things gives no great Name in the World; whereas to be acquainted with uncommon Things, though never so confusedly and imperfectly, always procures the Esteem and Reverence of those who willingly conceive a great Idea of what∣ever is out of their depth of Understanding: And that Experience determines all those who are more sensible to Vanity than to Truth, (which certainly make up the greatest Number) to a blind-fold Search of a specious, though chimerical, Knowledge of what is great, rare, and un∣intelligible.

How many are there that reject the Cartesian Philosophy, for that ridiculous Reason, That its Principles are too simple and easie: There are in this Philosophy no obscure and mysterious Terms; Women, and Persons unskill'd in Greek and Latin, are capable of learning it. It must then be, say they, something very inconsiderable, and unworthy the Application of great Genius's. They imagine, that Principles so clear and simple are not fruitful enough to explain the Effects of Nature, which they supposed to be dark, intricate, and confused: They see not presently the Use of those Principles, that are too simple and easie to stop their Attention long enough to make them understand their Use and Extent. They rather chuse to explain Effects whose Causes are unknown to them, by unconceivable Principles, than by such as are both simple and intelligible. For the Principles these Philosophers are wont to explain obscure Things by, are not only obscure themselves, but utterly incomprehensible.

Those that pretend to explain Things extremely intricate, by Principles clear and generally re∣ceiv'd, may easily be refuted, if they succeed not; since to know whether what they say be true, one needs only comprehend well what they say. The falsely-learn'd are not pleased with this, and obtain not the Admiration they pursue in using intelligible Principles; for, as soon as one un∣derstands their Notions, he plainly perceives that they say nothing: But when they make use of unknown Principles, and speak of very complex'd Things as though they exactly knew all their Relations, they are admired by their Hearers, who understand not what they say; because we are naturally inclin'd to reverence whatever goes above the reach of our Understanding.

Now, as obscure and incomprehensible Things seem to hang better with each other, than with such as are clear and intelligible; so incomprehensible Principles are much more made use of in very difficult and abstruse Questions, than such as are easie and intelligible. There is nothing so difficult, but, by the means of these Principles, Philosophers and Physicians will solve it in few Words; for their Principles being yet more incomprehensible than any Questions that can be pro∣posed them, those Principles being taken for granted, no Difficulty can afterwards put them to a Nonplus.

Thus, for instance, they boldly, and without boggling, make answer to these dark and unde∣termin'd Questions, viz. Why the Sun attracts Vapours? Why the Peruvian Bark stops the Quar∣••an Ague? Why Rhubarb purges Choler, and the Polychrest-Salt Phlegm? and the like. Most Men seem pretty well satisfied with their Answers, because obscure and incomprehensible Things shake Hands together: But unintelligible Principles suit not Questions that may be clearly and easily resolv'd, because by that Solution it plainly appears, that they are altogether insignificant. The Philosophers cannot explain, by their Principles, How Horses draw a Coach? Why Dust stops a Watch? How the Trepoly-Stone cleanses Metals, and a Brush our Clothes? For, they would appear ridiculous to all the World, should they suppose a Motion of Attraction, and At∣tractive Faculties, to explain why the Coach follows the Horses; and a Detersive Faculty in the Brush, for cleansing of Clothes, &c. So that their great Principles are only serviceable in dark and intricate Questions, by reason of their Incomprehensibility.

We ought not therefore to insist upon any Principle that appears not plain and evident, and of which it may be supposed, that some Nations reject it: But we must attentively consider the Ideas we have of Extension, Figure, and Local Motion, and the Relations they have between them: If we conceive them distinctly, and find them so plain and clear, as to be persuaded they were ever generally received by all Nations, we must dwell upon them, and examine all their Relati∣ons: But if they seem obscure and dark to us, we must endeavour to find others. For, if to avoid the Fear of Mistakes and Errours, it is always requisite to preserve Evidence in our Percep∣••ions, it follows, that we must argue only from clear Ideas, and from Relations distinctly known.

To consider in order the Properties of Extension, we must, as Des Cartes did, begin with the most simple Relations, and thence proceed to the more composed; not only because this Method is the most natural, and bears up the Mind in its Operations; but also because God ever acting with Order, and by the most simple Ways, that sort of Examination of our Ideas, and their Re∣lations, will better manifest to us his Works. And if we consider, that the most simple Relati∣ons always offer themselves first to the Imagination, when 'tis not determin'd to think rather on one Thing than another, it will appear, that to find out that Order we prescribe, and to discover very composed Truths, it is sufficient to look attentively, and without prejudice, upon Objects; provided always we skip not too hastily from one Subject to another.

When we look attentively upon Matter, we easily conceive that one Part may be separated from another; that is to say, we easily conceive a Local Motion, which Motion produces a Figure in each of the Bodies moved. The most simple of all Motions, which first occurs to the Imagina∣tion, is a Motion in a Right Line. Supposing then, that some Part of Matter is moved in a Right Line, it will necessarily displace some other Portion of Matter it shall find in its way, which latter shall circularly move to take the Room which the former has left: Hence comes a Circular Motion. And if we conceive infinite Motions in a Right Line, in an infinite number of similar Parts of that immense Extension we consider, it will again necessarily follow, that all these Bodies mutually hindring each other, shall all conspire by their reciprocal Action and Re-action, that is, by the mutual Communication of all their particular Motions, to produce one that is Circular.

That first Consideration of the most simple Relations of our Ideas, already discovers to us the necessity of the Vortexes of Des Cartes, that their Number will be so much greater, as the Mo∣tions in a Right Line of all the Parts of the Extension, having been more contrary to each other, shall with more difficulty have been reduc'd to the same Motion; and that amongst those Vor∣texes, the greatest will be those in which most Parts shall have concurr'd together to the same Motion, or whose Parts shall have had more Strength to continue their Motion in a Right Line.

In the mean while, care must be taken not to dissipate nor weary our Mind, by vainly apply∣ing it to the vast Number and unmeasurable Greatness of those Vortexes: We must rather insist upon some one of them for some time, and orderly and attentively enquire after all the Moti∣ons of the Matter it contains, and all the Figures wherewith the Parts of that Matter may be endued.

As there is no simple Motion but that in a Right Line, we must first consider it, as that in which all Bodies cotinually tend to move themselves; since God always acts by the most simple Ways: And if Bodies move Circularly, 'tis only because meeting with constant Oppositions, they are perpetually turn'd from their direct Motion. So that all Bodies being not of an equal Bulk, and the biggest having more Strength than others to continue their Motion in a Right Line, we easily conceive, that the smallest Bodies must sink to the Centre of the Vortex, and the big∣gest rise towards the Circumference; since the Lines which moving Bodies are suppos'd to de∣scribe at the Circumference of a Circle, are nearer to a Right Line, than those which they de∣scribe towards the Centre.

If we conceive again, that every Part of that Matter could not at first move, and meet with a perpetual Opposition to its Motion, without being smooth'd and rounded, and having its Angles broken off; we shall discover, that all that Extension will be compos'd of two sorts of Bodies, viz. of round Globules, which perpetually turn upon their own Centre, and that in several diffe∣rent Ways, and, besides that particular Motion, are carried about by the Motion common to all the Vortex; and of a very fluid and agitated Matter, produced from the Motion of the fore∣said Globules. Besides the Circular Motion common to all the Parts of the Vortex, that subtle Matter must yet have another particular, and almost direct, from the Circle of the Vortex to the Circumference, through the Intervals of the Globules, that leave a Passage open: So that the Motion composed of those Motions will represent a Spiral Line. That fluid Matter, call'd by Des Cartes, the first Element, being divided into Parts that are much smaller, and have not so much strength to continue their direct Motion, as the Globules, or second Element; 'tis evident, that the first Element must take up the Centre of the Vortex, and fill the empty Spaces which the Parts of the Second leave between them; and that the rest of the Vortex must be filled with those Parts of the Second, and come nearer to the Circumference, proportionably to their Bulk, or to the Force they have of continuing their Motion in a Direct Line. As to the Figure of the whole Vortex, after what has been said, it cannot be doubted, but that the Distance from one Pole to the other, will be shorter than that of the Line which cuts the Equator. And if we consider that the Vortexes surround and compress each other unequally, we shall plainly see that their Equator is a crooked irregular Line, that comes near to an Ellipsis.

These are the Things that offer themselves naturally to the Mind, when we attentively con∣sider what should happen to the Parts of Extension, perpetually tending to move in a Right Line, that is, in the most simple Motion. If we now suppose a Thing which seems most worthy the Divine Power and Wisdom, namely, That God has formed the whose Universe at once, in the same State those Parts would have naturally fallen into and disposed themselves in time, by the most simple Ways; and that he preserves them by the same natural Laws: In a word, if we compare our Ideas with the visible Objects, we shall conclude, that the Sun is the Centre of

the Vortex; that the Corporeal Light, which it diffuses every where, is nothing but the continual Effort of the little Globules, tending to remove from the Centre of the Vortex; which Light must be communicated in an Instant through those vast Spaces, because they being full of those Globules, one cannot be press'd upon, without the Motion of all the others that are opposite to it.

Several other Consequences may be drawn from what has been said, because the most simple Principles are the most fruitful to explain the Works of a Being which always acts by the most simple Ways. But we still want to consider some Things that will be incident to Matter. Let us then imagine, that there are several Vortexes, like to that we have described in few Words; that the Stars, which are so many Suns, are the Centres of those Vortexes, which surround each other, and are disposed in such a manner, as that they hinder one anothers Motion the least they can; but that before Things came to that Perfection, the weakest Vortexes were carried away, and as it were swallowed up by the strongest.

To understand this, we need but suppose that the first Element, which is at the Centre, may fly, and perpetually flies out through the Intervals of the Globules, towards the Circumference of the Vortex; and that at the same time that this Centre or Star empties it self through the Equator, other Matter of the first Element comes into it through the Poles; for neither the Star nor its Poles can empty themselves at one side, without being fill'd at another, since there is no Vacuity in Extension. But as an infinite number of Causes may hinder a great Quantity of the first Ele∣ment from coming into that Star, the Parts of the first Element that shall be forced to remain in it, will be necessitated to adapt themselves so, as to move one and the same way; which causes them to fasten and link themselves together, and constitutes them into Spots; which condensing and thickning into Crusts, cover by degrees the Centre; and out of the most subtil and agitated of all Bodies, are form'd into gross and solid Matter. This course sort of Matter is called by Des Cartes, the third Element, and is endued with an infinite number of Shapes and Figures, as is the first Element, from which it is generated and produced.

That Star being thus over-grown with Spots and Crusts, and become like the other Planets, has no longer a sufficient Strength to defend its Vortex against the continual Struggle and Irrupti∣ons of those that surround it; therefore it insensibly diminishes: The Matter that composes it, is dispersed on all sides, and the strongest of the neighbouring Vortexes carries the greatest part away, and at last involves the Planet that is the Centre of it. This Planet being wholly sur∣rounded with the Matter of the great Vortex, swims along in it, only keeping, together with some of the Matter of its own Vortex, its former Circular Motion, and takes at last such a Si∣tuation, as puts it in Aequilibrio with an equal Quantity of the Matter in which it swims. If it has but little Solidity and Magnitude, it descends very near the Centre of the surrounding Vor∣tex; because having no great Force to continue its Motion in a Right Line, it must take such a Place in that Vortex, as that an equal Quantity of the second Element, endeavouring to remove from the Centre, may be in Aequilibrio with it; that being the only Place where it can be ex∣actly balanc'd. If that Planet be of greater Bulk and Solidity, it must seek its Aequilibrium in a Place more distant from the Centre of the Vortex. And lastly, If there is no Place in the Vor∣tex, in which an equal Quantity of its Matter hath as much Solidity as this Planet, and conse∣quently as much Strength to continue its Motion in a Direct Line, perhaps because the Planet shall be very bulky, and over-grown with very solid and condens'd Crusts; it shall not stop in that Vortex, as finding no Aequilibrium in the Matter that composes it; but pass from Vortex to Vortex, until it meets with a Place in which it may be equally balanced by a competent Quan∣tity of Matter; so that it will sometimes be seen in its Passage, as the Comets are, when it shall be in our Vortex, and at a convenient Distance from us: But it will not be seen in a long time, when it shall be in other Vortexes, or in the utmost Boundary of ours.

If we hereupon conclude, that a single Vortex may, by reason of its Bulk, Strength, and ad∣vantageous Situation, insensibly undermine, involve, and carry away several Vortexes, and even such as shall have conquer'd others; it will necessarily follow, that the Planets that have been form'd in the Centre of the conquer'd Vortexes, being entered into the great and conquering Vor∣tex, place themselves in Aequilibrio with an equal Volume of the Matter in which they swim: So that if those Planets are unequal in Solidity, they will float at unequal Distances from the Centre of the Vortex in which they swim. But if two Planets have very near the same Force to continue that Direct Motion; or if a Planet carries in its small Vortex one or several other smaller Planets, which it shall have conquer'd, according to our Way of conceiving the Forma∣tion of Things: Then the smallest Planets will turn about the greatest, whilst the greatest shall turn upon its own Centre; and all these Planets shall be carried by the Motion of the great Vor∣tex, at a Distance very near equal from its Centre.

We are obliged, by the Light of Reason, to dispose in that Order the Parts that compose the whole Universe, which we imagine to have been formed by the most simple Ways. For all that had been said is only grounded on the Idea of Extension, the Parts of which are supposed to move in the most simple Motion, which is that in a Right Line. And when we examine by the Effects, whether we are mistaken in the Explication of Things by their Causes, we are surprized to see the Phenomaena of Celestial Bodies so perfectly agreeing with our Ratiocinations. For we perceive all the Planets that are in the middle of a small Vortex turning upon their own Centre, as the Sun does, and swimming in the Vortex of the Sun, and about the Sun; the smallest and least solid nearest to it, and the most solid at a greater distance. We likewise observe, that there are some, as the Comets, which cannot remain in the Vortex of the Sun: And lastly, that there

are several Planets, which have other smaller turning about them, as the Moon does about the Faith: Jupiter has four of them, Mars has three, and perhaps Saturn has so many, and so small, that they resemble a continued Circle, of which the thickness cannot be perceived, because of their too vast distance. Those Planets being the biggest we can observe, it may be imagin'd, that they have been produced from Vortexes which had a sufficient strength to conque•• others, before they were involved in the Vortex we live in.

All these Planets turn upon their own Centre, the Earth within 24. hours, Mars within 25. or thereabouts, Jupiter within about 10, &c. They all turn about the Sun, Mercury the nearest in about 4. Months; Saturn the remotest in about 30. Years, and those that are betwixt them in more or less time, which however keep not an exact proportion with their distance. For the mat∣ter in which they swim makes a swifter Circumvolution when 'tis nearer to the Sun, because the Line of its Motion is then shorter. When Mars is opposite to the Sun, he is then near enough to the Earth, but is at a vast distance from it when he is in Conjunction with him. The like may be said of the other superiour Planets, as Saturn and Jupiter; for the inferiour, as Venus and Mercury are, to speak properly, never opposite to the Sun. The Lines, which all the Planets seem to describe about the Earth, are no Circles, but are very like Ellipses, which Ellipses seem very much to differ, because of the different Situation of the Planets in reference to us. In short, whatever may be observed with any certainty in the Heavens, touching the Motion of the Planets perfectly agrees with what has been said of their Formation by the most simple ways.

As to the fixed Stars, Experience teaches us, that some diminish and entirely vanish away, whilst others that are wholly new appear; the lustre and bulk of which sensibly increase. They increase or diminish proportionably as the Vortexes, in whose Centre they lye, admit more or less of the first Element. We cease to see them when they are overspread with Spots and Crusts, and begin to discover them, when those Spots, which obstruct their lustre, are entirely dissipated. All these Stars keep very near the same distance from each other, since they are Centres of Vor∣texes which are not conquer'd, and remain Stars as long as they can resist the Invasion of others. They are all bright like as many little Suns, because they are all, as he is, the Centers of uncon∣quer'd Vortexes. They are all at an unequal distance from the Earth, though they appear as if they were fastned to a Vault; for if the Parallaxe of the nearest with the remotest has not yet been observable, by the different situation of the Earth from 6 to 6 Months; it is because that difference is too inconsiderable in reference to our distance from the Stars, to make that Parallaxe sensible. Perhaps by means of the Telescopes, it will one day or other become somewhat obser∣vable. In short, whatever the Senses and Experience may observe in the Stars, differs not from what we have discover'd by the Mind, whilst we examin'd the most simple and natural Relations that are betwixt the Parts and the Motions of Extension.

To search after the Nature of Terrestrial Bodies; we must conceive that the first Element be∣ing made up of an infinite number of different Figures, the Bodies that result from their Mixture must be very different. So that there will be some whose Parts shall be branched, others long, others very near round, but all irregular, several ways. When their Parts are branched and gross, they are hard, but flexible, and not elastick, as Gold: If their Parts be not so gross, they are soft, and fluid, as Gums, Fats, Oyles; but if their branched Parts be extremely fine, they are like the Air. If the long Parts of Bodies are gross and inflexible, they are pungent, incorruptible, and dis∣solvible, as Salts; if those long Parts be flexible, they are insipid like Water; if the gross Parts be of very irregular and different Figures, they are like Earth and Stones. In short, thence must needs arise Bodies of several different Natures, and two will hardly be found exactly alike, by rea∣son of the infinite number of Figures incident to the first Element, which can never be complicated after the same manner in two different Bodies. What Figure soever those Bodies may have, if their Pores be large enough to give way to the second Element's passing all manner of ways, they will be transparent like Air, Water, Glass, &c. If the first Element entirely surrounds some of their Parts and affords them a sufficient force and commotion to repel the second Element on all sides, they will appear Luminous like flame; if they drive back all the second Element that falls upon them, they will be very white; if they receive it without repelling it, they will be very black; and last∣ly, if they repel it by several Concussions and Vibrations, they will appear of different colours.

As to their Situation, the heaviest, or those that have least force to continue their direct Motion, will be the nearest to the Centre, as are Metals: Earth, Water and Air, will be more remote, and all Bodies will keep the same Situation in which we observe them; because they will recede from the Centre of the Earth, as far as their Motion will allow.

It must not seem strange that I now say, that Metals have less force to continue their direct Motion, than Earth, Water, and other less solid Bodies, though I have formerly said, that the most solid Bodies have more strengh than others to continue their direct Motion. For the Rea∣son why Metals are not so apt to continue to move, as Earth and Stones, is that Metals have less Motion in themselves; it being true however, that of two Bodies unequal in solidity, but mo∣ved with an equal swiftness, that the most solid will have more force to pursue its Motion in a right Line; because the most solid has then the greater Motion, and that Motion is the Cause of strength.

But if we would understand the Reason why Bodies, gross and solid, are heavy towards the Center of Vortexes, but light at a considerable distance from it; we must know, that these Bodies receive their Motion from the subtle matter that invirons them, and in which they swim. Now that subtle matter actually moving in a Circular Line, and only tending to move in a right Line;

it only Communicates that Circular Motion to the gross Bodies it carries along with it: and as to its tendency to remove from the Centre in a Right Line, it only communicates that to them as far as it is a necessary sequel of the Circular communicated Motion. For it must be observed, that the Parts of the subtle matter tending to different sides, can only compress the gross Body they convey; since that Body cannot go several different ways at the same time. But because the subtle Matter, that lies about the Centre of the Vortex, has a far greater Motion than that which it spends in circulating, and because it communicates only its Motion Circular, and common to all its Parts, to the gross Bodies which it carries; and that if these Bodies should chance to have more Motion than what is common to the Vortex, they would soon lose that overplus, by communica∣ting it to the little Bodies they meet with; thence 'tis evident, that gross Bodies, towards the Centre of the Vortex, have not so much Motion as the Matter in which they swim; each part of which has its own particular and various Motion, besides the Cicular and common. Now if gross Bo∣dies have less Motion, they have less Tendency to move in a right Line, and if they have less Ten∣dency, they are forc'd to yield to those that have more, and consequently to approach the Centre of the Vortex, that is, in short they must be heavyer, as they are more gross and solid.

But when solid Bodies are very remote from the Centre of the Vortex, as the Circular Mo∣tion of the subtle Matter is then very great, because it spends very near its whole Motion in wheeling about; Bodies have then so much more Motion as they have more Solidity; because they go as swift as the subtle Matter in which they swim: and so they have more force to con∣tinue their direct Motion. Wherefore gross Bodies at a certaine distance from the Centre of the Vortex, are so much lighter as they are more solid.

This makes it apparent, that the Earth is metallick towards the Centre, and not so solid a∣bout the Circumference; that Water and Air must remain in the Situation wherein we see them; but that all those Bodies are ponderous; the Air as well as Gold and Quick-silver; because they are more solid and gross than the first and second Element. This shews likewise that the Moon is at too great a distance from the Centre of the Vortex of the Earth to be heavy, though it be solid; that Mercury, Venus, the Earth, Mars, Jupiter, and Saturn, cannot fall into the Sun, and that they are not solid enough to travel out of this Vortex, as the Comets do; that they are in Aequilibrio with the Matter in which they swim, and that if a Musket Ball, or a Cannon Bullet, could be shot high enough, those two Bodies would become little Planets, or perhaps Comets, that would not stay in any Vortex, as being endued with a competent Solidity.

I pretend not to have sufficiently explain'd all the things I have mention'd, or to have de∣duced from the simple Principles of Extension, Figure and Motion all the possible Inferences, I only intended to shew the Method Des Cartes has used in the discovery of Natural things, that this Method and his Ideas may be compared with those of other Philosophers; I design'd here no more, and yet I may venture to assert, that if one would supersede admiring the Virtue of the Loadstone, the regular Motion of the ebbing and flowing of the Sea, the noise of Thunder, the Generation of Meteors; in short, if any desire to get a well-grounded Knowledge of Natu∣ral Philosophy, as he can doe nothing better than to read and medi••ate his Books; so he can doe nothing at all, unless he follows his Method, I mean unless he Reason as he did, upon clear I∣deas, still beginning with the most simple and familiar.

Neither do I pretend that this Author is Infallible; for I think I can demonstrate that he has been mistaken in several places of his works. But 'tis more advantageous for his Readers to be∣lieve that he hath been deceived, than if they were persuaded that whatever he said was true: A Man that should take him to be infalible would read him without Examination, believe him without understanding what he says, learn his Opinions as we learn History, and would never form and perfect his Mind. He himself advertises his Readers to observe whether he be deceived, and to believe nothing of what he says, but what the Evidence compells them to. For he is not like those false pretenders to Science, who endeavouring to Lord it over the Minds, will be believed upon their own word; and who instead of making Men the Disciples of the inward Truth, by proposing only clear and distinct Ideas, labour what they can to submit them to the Authority of Heathens, and press upon Men incomprehensible Opinions by unintelligible Reasons.

The chief thing that is found fault with in Des Cartes's System, is the manner in which he feigns that the Sun, Stars, Earth, and all the Bodies that surround us, have been produced; for∣asmuch as it seems contrary to what Holy Writ teaches us of the Creation of the World; since, according to him, one would say, that the whole Universe has been formed of its own accord, so as we see it now a-days; to which several Answers may be made.

First, As to the pretended Contrarieties betwixt Moses and Des Cartes, those that assert it, have not perhaps examin'd them both, with as much Attention as those who have shewn, by pub∣lick Writings, that the sacred History of the Creation perfectly agrees with the opinion of that Philosopher.

But the chief Answer is, that Des Cartes never pretended that things should ever have been made by degrees, and as he describes them. For at the first Article of the Fourth Part of his Philosophical Principles, which runs thus: That the former Hypothesis is to be retain'd, notwith∣standing its being false, to find out the true Causes of natural Things; he expresly asserts the con∣trary in these words. Though I pretend not that the Bodies of this visible World were ever produ∣ced in the manner that has been described before, of which the Reader has been already sufficiently fore∣warn'd; yet I must still keep to the same Hypothesis, to explain what appears upon Earth; For if I may, as I hope I can, plainly shew by those means the most intelligible and certain Causes of all Na∣tural

things, and they cannot be found out another way; I may thence reasonably conclude, that though the World was not at the Beginning fram'd in this manner, but created immediately by God, yet the Nature of all things it contains ceases not to be the very same, as though they had been produced in that very method.

Des Cartes knew that to understand the Nature of things, they must be consider'd in their Birth and Original, and that beginning with those that are most simple, we ought to drive them up to the Fountain head, and that the business is not to examine, whether God working by the most simple ways, formed the World by degrees, or struck it out at a single Blow; but that, in what manner soever God may have produced his Works, they ought to be first consider'd in their Principles, if we would understand them, and afterwards we should observe, how consistent our thoughts are with the Operations of God, by comparing them together. He knew that the Laws of Nature, by which God preserves all his Works in their present Order and Situation are the same Laws, with those by which he might have formed and disposed them; It being evident to all considering Men, that if God had not disposed his Works in an instant, in the same manner they would have order'd and postur'd themselves in time; the whole Oeconomy of Nature would be destroy'd, since the Laws of Preservation would be contrary to those of the first Creation. If the whole Universe remains in the Order in which we see it, 'tis because the Laws of Motion which preserve it in that Order, were capable of producing it in it; and if God had established it in an Order different from that into which those Laws of Motion should have put it, all things would be turned upside down, and place themselves by the force of those Laws, in the Order which they at present keep.

A Man desires to discover the Nature of a Chicken, to that end he opens every day Eggs taken from under a Brood-Hen; he examines what part moves and grows first, he quickly perceives that the Heart begins to beat, and to drive out Blood through small Conduits on all sides, that are the Arteries; which Blood comes back to the Heart through the Veins, that the Brain like∣wise appears at first, and that the Bones are the last formed. By that he frees himself from ma∣ny Errours, and even draws from those Observations several Consequences very useful for the Knowledge of living Creatures. What fault may be found with the conduct of such a Man, and how may it be given out, that he pretends to persuade, that God formed the first Chicken, by creating an Egg, and giving it a competent degree of heat to hatch it? because he tries to disco∣ver the Nature of Chickens in their first Formation?

Why then should Des Cartes be accused of being opposite to the Holy Scriptures, for that de∣signing to discover the Nature of visible things, he examines the formation of them by the Laws of Motion, which are inviolably observ'd on all occasions. He never doubted but that the World was created at first with all its perfection; that there were Sun, Earth, Moon and Stars; that in the Earth there were not only the Seeds of Plants, but also the Plants themselves; and that Adam and Eve were not born Infants, but made adult. The Christian Faith teaches us that, and natural Reason persuades us the same; for when we consider the infinite Power of God, we can∣not think he should ever have made any thing which was not altogether perfect. But as we should better understand the nature of Adam and Eve, and the Trees of Paradise, by examining how Children are insensibly form'd in their Mothers Womb, and how Plants are deriv'd from their Seeds, than by merely considering how they were when Created by God at the Creation of the World; so if we can find out Principles very simple and easie, out of which, as out of some Seeds, we can ma∣nifestly shew the Stars, the Earth, and all visible things might have been produced; though we ve∣ry well know that it was never so, (yet) that will be more conducible to explain their Nature, than if we should only describe them so as they now are, or as we believe they were Created, and be∣cause I suppose I have found out such Principles, I shall indeavour briefly to Explain them.

Des Cartes was persuaded that God formed the World all at once; but he also believed that God Created it in the same State and Order, and with the same Disposition of Parts, in which it would have been, had it been made gradually, and by the most simple ways. And that thought is worthy both of the Power and Wisdom of God; of his Power, because he has made in a Mo∣ment all his Works in the highest Perfection; and of his Wisdom, because he has shewn that he perfectly foresaw whatever could befall Matter, if it were moved by the most simple ways: and likewise because the Order of Nature could not subsist, if the World had been produced by ways, that is, by Laws of Motion, contrary to the Laws by which it is preserv'd, as I have alrea∣dy mention'd.

'Tis ridiculous to say, that Des Cartes believed the World might have been formed of it self, since he owns with all those that follow the light of Reason, that Bodies cannot move them∣selves by their own strength; and that all the immutable Laws of the Communication of Moti∣ons are but consequences of the immutable Will of God, who always acts in the same manner. His proving that God alone gives Motion to Matter, and that Motion produces in Bodies all their different Forms, was sufficient to hinder the Libertines from making an Advantage of his System. On the contrary, if Atheists should reflect on the Principles of this Philosopher, they would quickly be forced to confess their Errours; for if they can assert, with the Heathens, that Matter is uncreated, they cannot also maintain that it can move it self by its own Power: So that Atheists would at least be obliged to acknowledge the true Mover, if they refused to con∣fess the true Creatour. But the Ordinary Philosophy affords 'em sufficient pretences to blind themselves, and defend their Errours; for it speaks of some impress'd Virtues, certain motive Faculties, in a word, of a certain Nature which is the Principle of Motion in every thing;

And though they have no distinct Idea of it, yet by reason of the Corruption of their Heart, they willingly put it in the room of the true God, imagining that it performs all the Wonders that they see occur.

CHAP. V.

An Explication of the Principles of the Peripatetick Philosophy, in which is shewn, that Aristotle never observed the Second Part of the General Rule; and his Four Elements, with the Elementary Qualities, are examined.

THat the Reader may compare the Philosophy of Des Cartes with that of Aristotle, it will be convenient to set down in few words what the latter has taught concerning Elements and Natural Bodies in general; which the most learned believe he has done in his Four Books Of the Heavens. For his Eight Books of Physicks belong rather to Logick, or perhaps to Metaphysicks, than to Natural Philosophy; since they consist of Nothing but loose and general terms, that of∣fer no distinct and particular Idea to the Mind. Those Four Books are entituled Of the Heavens, because the Heavens are the chief amongst the simple Bodies which he treats of.

That Philosopher begins his Work by proving that the World is perfect, in the following man∣ner. All Bodies have three Dimensions and cannot have more, because the number three compre∣hends all, according to the Pythagoreans. But the World is the Coacervation of all Bodies, and therefore the World is perfect. By that ridiculous Proof, it may also be demonstrated, that the World cannot be more imperfect than it is, since it cannot be composed of parts that have less than three Dimensions.

In the Second Chapter, he first supposes some Peripatetick Truths, as that all Natural Bodies have of themselves the force of moving, which he proves neither here nor elsewhere; but on the contrary asserts, in the First Chapter of his Second Book of Physicks, that to endeavour to prove it is absurd, because 'tis evident of it self, and that none but those who cannot distinguish what is known of it self from what is not, insist upon proving plain by obscure things. But it has been shewn elsewhere, that it is altogether false that natural Bodies should have of themselves the force of moving, and it appears evident only to such as follow, with Aristotle, the Impressions of their Senses, and make no use of their Reason.

Secondly, He says that all local Motion is made in a Line, either direct or circular, or com∣posed of both; but if he would not think upon what he so rashly proposes, he ought at least to have open'd his Eyes that he might see an Infinite number of different Motions, which are not made of either the right or circular: Or rather he ought to have thought that the Motions composed of the direct may be infinitely varied, when the compounding Motions increase or di∣minish their swiftness in an infinite number of different ways, as may be observed by what has been said before . There are, says he, but two simple Motions, the right and the Circular, and therefore all the others are composed of them. But he mistakes, for the Circular Motion is not simple, since it cannot be conceived, without thinking upon a Point to which it relates, and what∣ever includes a Relation is relative and not simple. This is so true that the Circular Motion may be conceived as produced from two Motions in a right Line, whose Swiftness is unequal, ac∣cording to a certain Proportion. But a Motion composed of two others, made in a right Line, and variously increasing or diminishing in swiftness, cannot be simple.

Thirdly, He says that all the simple Motions are of three sorts, one from the Centre, the other towards the Centre, and the third about it. But 'tis false that the last, viz. the Circular Moti∣on should be simple, as has been already said. And 'tis false again that there are no simple Mo∣tions besides upwards and downwards. For all the Motions in a right Line are simple, whether they approach to, or remove from the Centre, the Poles, or any other Point. Every Body, says he, is made up of three Dimensions, and therefore the Motion of all Bodies must have three sim∣ple Motions. What Relation is there betwixt simple Motions and Dimensions? Besides, every Body has three Dimensions, and none has three simple Motions.

Fourthly, He supposes that Bodies are either simple or composed, and calls simple Bodies, those that have the force of moving themselves, as Fire, Earth, &c. adding, that the compounded re∣ceive their Motion from the compounding. But in that sense there are no simple Bodies, since none have in themselves any Principle of their Motion: there are also none composed, since there are no simples of which they should be made; and so there would be no Bodies at all. What Fancy is it, to define the simplicity of Bodies by a Power of moving themselves. What distinct Ideas can be fixed to the Words of simple and composed Bodies, if the simple are only defined in Relation to an Imaginary moving force? But let us see what Consequences he draws from those Principles. The Circular Motion is simple. The Heavens move Circularly, and there∣fore their Motion is simple: But simple Motion can be ascribed only to a simple Body, that is to say, to a Body that moves of it self; And therefore the Heavens are a simple Body distinguished from the four Elements, that move in right Lines. 'Tis plain enough that such Arguments con∣tain nothing but false and absurd Propositions. Let us examine his other Proofs, for he alleadges a great many shameful and nonsensical ones, to prove a thing as useless as it is false.

His second Reason to shew that the Heavens are a simple Body distinguished from the Four E∣lements, supposes that there are two sorts of Motion, one natural, and the other violent or against Nature. But 'tis sufficiently plain to all those that judge of things by clear and distinct Ideas, that Bodies having not in themselves any such Principle of their Motion as Aristotle pretends, there can be no Motion violent or against Nature. 'Tis indifferent to all Bodies to be moved or not, either one way or another. But this Philosopher, who judges of things by the Impressions of the Senses, imagines that those Bodies, which by the Laws of the Communications of Mo∣tions, always place themselves in such or such a Situation, in reference to others, doe it of their own accord, and because it is most convenient for them, and best agrees with their Nature. Here follows the Argument of Aristotle.

The Circular Motion of the Heavens is natural, or against Nature. If natural, the Heavens are a simple Body distinguished from the Elements, since the Elements never move circularly by a natural Motion. If the Circular Motion of the Heavens is against their Nature, they will be some one of the Elements, as Fire, Water, &c. or something else. But the Heavens can be none of the Elements: as for instance, if the Heavens were Fire, that Element tending naturally upwards, the Heavens would have two contrary Motions, viz. the circular and the ascending, which is im∣possible. If the Heavens be some other Body, which moves not circularly by its own Nature, they will have some other natural Motion, which cannot likewise be; for if that Motion be as∣cending, they will be Fire or Air; and if descending, Water or Earth: Therefore, &c. I shall not insist upon shewing the particular Absurdities of those Reasonings, but only observe in ge∣neral, that all that which this Philosopher here says, has no signification, and that there is nei∣ther Truth nor Inference well drawn. His third Reason is as follows.

The first and most perfect of all simple Motions must be that of a simple Body, and of the first and most perfect among simple Bodies. But the circular Motion is the first and most perfect amongst simple Motions, because every circular Line is perfect, and that no right Line is so. For if it be finite, something may be added to it; if infinite, it is not yet perfect, since it has no end , and that things are not perfect but when they are finished; and therefore the circular Motion is the first and most perfect of all, and a Body moving circularly is simple, and the first and most Divine amongst simple Bodies. Here you have his fourth Reason.

Every Motion is either natural, or not; but every Motion which is not natural to some Bo∣dies, is natural to some others: For, we see that the ascending and descending Motions, which are not natural to some Bodies, are so to others; for Fire naturally descends not, but Earth does. Now the Circular Motion is not natural to any of the Four Elements; there must then be a sim∣ple Body to which that Motion is natural; and therefore the Heavens, which move Circularly, are a simple Body, distinguished from the Four Elements.

Lastly, The Circular Motion is either natural or violent to some Body or other: If it be na∣tural, 'tis evident that Body must be one of the most simple and perfect: But if it be against Nature, 'tis strange how that Motion endures for ever; since we see that all Motions against Nature are of a short continuance. And therefore we must believe, after all those Reasons, that there is some Body separated from all those that environ us, whose Nature is the more perfect, as it lies at a greater distance. Thus argues Aristotle; but I defie the best and most intelligent of his Interpreters to fix distinct Ideas to his Words, and to shew that this Philosopher begins with the most simple Things, before he speaks of the more composed; which is however altoge∣ther necessary to exact Reasonings, as I have already proved.

If I were not afraid of being tedious, I would be at the pains to translate some Chapters of Aristotle: But besides that none who can understand him, care to read him in English, or in any other vulgar Tongue, I have sufficiently shewn, by what I have related from him, that his Way of Philosophizing is wholly unserviceable to the Discovery of Truth: For, he says himself, in the Fifth Chapter of this Book, That those that mistake at first in any thing, mistake ten thou∣sand times more, if they proceed: So that it being apparent, that he knows not what he says in the two first Chapters of his Book, we may reasonably believe, that it is not safe to yield to his Authority, without examining his Reasons. But that we may be the more persuaded of it, I proceed to shew, that there is no Chapter in this First Book but has some Impertinency.

In the Third Chapter he says, That the Heavens are incorruptible, and uncapable of Alteration; of which he alledges several Childish Proofs, as, that they are the Habitation of the Immortal Gods, and that no Change was ever observed in them. This last Proof would be good enough, could he say, that ever any Body was come back from thence, or that he had approached Celesti∣al Bodies sufficiently near to observe their Alterations. And yet I doubt whether at this time any one should yield to his Authority, since Telescopes assure us of the contrary.

In the Fourth Chapter he pretends to prove, That the Circular Motion has no Opposite; though it be plain, that the Motion from East to West is contrary to that which is made from West to East.

In the Fifth Chapter he very weakly proves, That Bodies are not Infinite; drawing his Argu∣ments from the Motion of simple Bodies: For what hinders, but there may be above his Primum mobile some unmovable Extension.

In the Sixth, he loses time in shewing, That the Elements are not Infinite: For, who can doubt of it, when he supposes, with him, that they are included within the surrounding Hea∣vens?

But he ridicules himself, by drawing his Proofs from their Gravity and Lightness. If Ele∣ments, says he, were Infinite, there would be an Infinite Heaviness and Lightness; which cannot be: Ergo, &c. Those that desire to see his Arguments at length, may read them in his Books; for I reckon it a loss of Time to relate them.

He goes on in the Seventh Chapter to prove, That Bodies are not Infinite; and his first Argu∣ment supposes it necessary for every Body to be in Motion, which he neither does nor can de∣monstrate.

In the Eighth he asserts, That there are not many Worlds of the same Nature, by this ridicu∣lous Reason, That if there were another Earth besides this we inhabit, the Earth being ponderous of its own nature, it would fall upon ours, which is the Centre of all ponderous Bodies. Whence has he learned this, but from his Senses?

In the Ninth he proves, That it is not so much as possible that there should be several Worlds, because if there was any Body above the Heavens, it would be simple or composed, in a natural or violent State; which cannot be, for Reasons which he draws from the Three sorts of Motions already spoken of.

In the Tenth he asserts, That the World is Eternal, because it cannot have had a Beginning, and yet last for ever; because we see, that whatever is made, is corrupted in Time. He has learned this likewise from his Senses: But who has taught him, that the World will always endure?

He spends the Eleventh Chapter in explaining what Incorruptible signifies; as though Equivoca∣tion was here very dangerous, or that he was to make a great Use of his Explanation. However, that Word Incorruptible is so clear of it self, that Aristotle needed not have troubled himself with explaining in what Sense it must be taken, or in what Sense he takes it. It had been more convenient to define an infinite Number of Terms, very usual with him, which raise nothing but sensible Ideas; for so perhaps we should have learned something by the reading of his Works.

In the Last Chapter of this First Book of the Heavens, he endeavours to shew, That the World is incorruptible, because 'tis impossible it should have had a Beginning, and yet last eternally. All Things, says he, subsist either for a finite or infinite Time; but what is only infinite in one sense, is neither finite nor infinite, and therefore nothing can subsist in that Manner.

This is the way of arguing with the Prince of Philosophers, and the Genius of Nature; who, instead of discovering, by clear and distinct Ideas, the true Cause of natural Effects, lays the Foundation of a Pagan Philosophy upon the false and confused Ideas of the Senses, or upon such Ideas as are too general to be useful to the Search after Truth.

I condemn not Aristotle for not knowing that God has created the World in Time, to manifest his Power, and the Dependency of Creatures; and that he will never destroy it, to shew that he is immutable, and never repents of his Designs: But I may find fault with him for proving, by trifling Reasons, that the World is of Eternal Duration. For, though he be sometimes excusa∣ble as to the Opinions he maintains, yet he's for the most part intollerable as to the Reasons he alledges, when he treats of Subjects that are somewhat difficult. What I have already said, may perhaps be sufficient to evince it; though I have not related all the Errours I have met with in the Book whence the former are extracted, and that I have endeavour'd to make him speak plainer than is customary with him.

But for an entire and full Conviction, that the Genius of Nature will never discover the secret Springs and Contrivances of it, it will be convenient to shew, that his Principles, upon which he reasons for the Explication of natural Effects, have no Solidity in them.

'Tis evident that nothing can be discover'd in Physicks, without beginning with the most simple Bodies; that is, with the Elements; into which all others are resolv'd, because they are con∣tain'd in them either actually or potentially, to speak in a Peripatetick Stile. But no distinct Ex∣plication of those simple Bodies can be found in the Works of Aristotle; whence follows, that his Elements being not clearly known, 'tis impossible to discover the Nature of Bodies which are compos'd of them.

He says indeed, that there are four Elements, Fire, Air, Water and Earth; but he gives no clear Manifestation of their Nature, by any distinct Idea: He pretends not that those Elements are the Fire, Air, Water and Earth that we see; for if it were so, our Senses at least would afford us some Knowledge of them. I grant that in several places of his Works he endeavours to explain them by the Qualities of Heat and Cold, Moisture and Dryness, Gravity and Levity. But that Method is so impertinent and ridiculous, that it cannot be conceiv'd how so many Learned Men could be satisfied with it; which I proceed to demonstrate.

Aristotle pretends in his Book of the Heavens, that the Earth is the Centre of the World, and that all Bodies which he is pleas'd to call simple, because he supposes that they are mov'd by their own Nature, must move by simple Motions. He asserts, that besides the Circular Motion, which he pretends to be simple, and by which he proves that the Heavens, which he supposes to move circularly, are a simple Body, there are two other simple Motions; one downwards, from the Cir∣cumference to the Centre; and the other upwards, from the Centre to the Circumference: That those simple Motions are proper to simple Bodies, and consequently that Earth and Fire are such Bodies; one of which is altogether heavy, and the other perfectly light. But because Gravity and Levity may be proper to a Body, either wholly, or in part, he concludes that there are two other Elements, or simple Bodies, one of which is partly light, and the other partly ponderous, viz. Water and Air. Thus he proves that there are four Elements, and no more.

It is plain to all those who examine the Opinions of Men by their own Reason, that all those Propositions are false, or cannot at least be taken for clear and undeniable Principles, which may afford very plain and distinct Ideas, whereon to lay the Foundation of Natural Philosophy. 'Tis certain that nothing can be more absurd, than to establish the Number of Elements upon the ima∣ginary Qualities of Heaviness and Lightness; saying, without any farther Proof, that some Bodies are ponderous, and others light, of their own Nature: For if any thing may be asserted without Proof, it may be said that all Bodies are naturally heavy, and endeavour to approach the Centre of the World, as the place of their Rest. And the contrary may be asserted too, viz. That all Bo∣dies are light of their own Nature, and tend to rise to the Heavens, as to the place of their great∣est Perfection. For if you object to him who maintains the Gravity of Bodies, that Fire and Air are light; he needs but answer, that Fire and Air are not light; but that being less ponderous than Earth and Water, they seem to us to be light: And that it goes with those Elements, as with a piece of Wood that appears light upon the Water; not by reason of any natural Levity, since it falls down when in the Air; but because Water being heavier, seizes the lower Place, and forces it to ascend.

On the contrary, If you object to him that defends the natural Levity of Bodies, that Earth and Water are ponderous; he will likewise answer, That those Bodies seem heavy, because they are not so light as those that surround them: That Wood, for instance, appears to be ponderous when in the Air, not because of its natural Gravity, since it ascends when in the Water, but because it is not so light as Air.

And therefore 'tis ridiculous to suppose, as an undeniable Principle, that Bodies are either light or heavy of their own Nature; it being, on the contrary, evident, that none has the Force of mo∣ving it self, and that 'tis indifferent to be moved either upwards or downwards, to the East or to the West, to the South or to the North, or in any other possible manner.

But let us grant to Aristotle, That there are four Elements, such as he pretends; two of which are heavy, viz. Earth and Water; and the two other light of their own Nature, viz. Fire and Air; what Consequence may be drawn from thence, for the Knowledge of the Universe? Those four Elements are not the visible Fire, Air, Water and Earth, but something quite different, which we know neither by the Senses, nor by Reason, having no distinct Idea of them. Let all natural Bodies be compos'd of them, since Aristotle has said it: But the Nature of those Compounds is still unknown, and cannot be discovered, but by knowing the four Elements, or the simple Bodies of which they are made, since the Composed is known only by the Simple.

Fire, says Aristotle, is light by its own Nature; the ascending Motion is simple: Fire is there∣fore a simple Body, since Motion must be proportion'd to the Moveable. Natural Bodies are compos'd of simple, there is then Fire in all natural Bodies, but a Fire which is not like to that we see; for Fire is often but in potentia in the Bodies that are made of it. What signifie all these Peripatetick Discourses? That there is Fire in all Bodies, either actual or potential, that is to say, that all Bodies are compos'd of something we see not, and the Nature of which is wholly un∣known unto us. Now we have made a very fair Progress.

But though Aristotle shews us not the Nature of Fire, and other Elements, of which all Bodies are made up; yet one may imagine, that he will at least discover their principal Qualities and Properties. Let us also examine what he says upon that Account.

He declares that there are four principal Qualities which belong to the Sense of Touching, viz. Heat, Cold, Humidity and Siccity; of which all the other are compos'd. He distributes those primitive Qualities into the four Elements, ascribing Heat and Dryness to Fire, Heat and Moisture to the Air, Cold and Moisture to Water, and Cold and Dryness to Earth. He asserts that Heat and Cold are active Qualities; but that Dryness and Moisture are passive. He defines Heat, What congregates Things of the same kind; Cold, What congregates Things either of the same, or of dif∣ferent Species; Moisture, What cannot easily be contain'd in its own Limits, but is easily kept with∣in foreign Bounds; and Dryness, What is easily contain'd within its own Limits, but will hardly be adapted to the Bounds of surrounding Bodies.

Thus, according to Aristotle, Fire is a hot and dry Element, and therefore congregates Homoge∣neous Things, is easily contain'd within its own Limits, and hardly within others: Air is a hot and moist Element, and therefore congregates Homogeneous Things, can hardly be kept within its own Limits, but easily within others: Water is a cold and moist Element, and therefore congregates both Homogeneous and Heterogeneous Things, is hardly contain'd within its own Limits, but easily with∣in others: And lastly, Earth is a cold and dry Element, or such an one as aggregates Things, both of the same and different Natures, is easily contain'd within its own Limits, but can hardly be adapt∣ed to others.

There you have the Elements explain'd, according to the Opinion of Aristotle, or the Definitions he has given of their principal Qualities; and because, if we may believe him▪ the Elements are simple Bodies, out of which others are constituted; and their Qualities are simple Qualities, of which all others are compos'd, the Knowledge of those Elements and Qualities must be very clear and distinct, since the whole Natural Philosophy, or the Knowledge of all sensible Bodies, which are made of them, must be deduc'd from thence.

Let us then see what may be wanting to those Principles. First, Aristotle fixes no distinct Idea to the Word Quality: It cannot be known whether by Quality he understands a real Being distin∣guish'd from Matter, or only a Modification of Matter; he seems one while to take it in the for∣mer, and at another time in the latter Sense. I grant that in the 8th Chapter of his Categories, he

defines Quality, that by which Things are denominated so or so; but that is not plain and satisfacto∣ry. Secondly, His Definitions of the four Primitive Qualities, viz. Heat, Cold, Moisture and Dryness, are either false, or useless. We will begin with his Definition of Heat: Heat, says he, is that which congregates Homogeneous Things.

First, Though that Definition should be true, That Heat always congregates Homogeneous Bo∣dies; yet we cannot see how it perfectly explains the Nature of Heat.

Secondly, 'Tis false that Heat congregates Homogeneous Things; for Heat dissipates the Par∣ticles of Water into Vapour, instead of heaping them together: It congregates not likewise the Parts of Wine, or any Liquor or Fluid Body whatsoever, even to Quick-silver. On the contrary, it resolves and separates both Solid and Fluid Bodies, whether of the same or different Natures; and if there be any, the Parts of which Fire cannot dissipate, it is not because they are homoge∣neous, but because they are too gross and solid to be carry'd away by the Motion of the fiery Particles.

Thirdly, Heat, in reality, can neither congregate nor segregate the Parts of any Body whatso∣ever; for, that the Parts of Bodies may be congregated, separated or dissipated, they must be mo∣ved: But Heat can move nothing, or at least, it appears not that it can move Bodies; for though we consider Heat with all the possible Attention, we cannot discover that it may communicate to Bodies a Motion which it has not it self. We see, indeed, that Fire moves and separates the Parts of such Bodies as lie expos'd to its Action, but it is not perhaps by its Heat, it being not evident whether it has any; it is rather by the Action of its Parts, which we visibly perceive to be in a con∣tinual Motion; for these fiery Particles striking against a Body, must needs impart to it somewhat of their Motion, whether there is or is not any Heat in Fire. If the Parts of that Body be not very solid▪ Fire will dissipate them; but if they be very gross and solid, Fire can but just move them, and make them slide one over the other. And Lastly, If there be a Mixture of subtile and gross Parts, Fire will only dissipate those which it can push so far as to separate them from the others. So that Fire can only separate; and if it congregate, 'tis only by Accident. But Aristotle asserts quite contrary: Separating, says he, which some ascribe to Fire, is but congregating Homo∣geneous Things; for 'tis only by Accident that Fire carries off Things of different Nature.

If this Philosopher had at first distinguished the Sensation of Heat, from the Motion of the small Particles, of which the Bodies called hot are composed, and had afterwards defined Heat, taken from the Motion of Parts, by saying, that Heat is what agitates and separates the invisible Parts, or which visible Bodies are made up; he would have given a tolerable definition of Heat; though not full and satisfactory: because it would not accurately discover the Nature of Motion in hot Bodies.

Aristotle defines Cold, what congregates Bodies of the same, or different Nature: but that De∣finition is worth nothing, for Cold congregates not Bodies. To congregate them, it must move them: but if we consult our Reason we shall find, that Cold can move nothing; for we under∣stand by that word, either what we feel when we are cold, or what causes our Sensation. As to our Sensation, 'tis plain that it is merely Passive, and can neither move nor drive any thing. And as to the Cause of that Sensation, reason tells us, if we examine things, that it is merely rest, or a Cessation of Motion: So that Cold in Bodies being no more than the Cessation of that sort of Motion which attends Heat, 'tis evident that if Heat separate, Cold does not. And therefore Cold coacervates neither things of the same, nor of different nature; since what cannot drive on Bodies cannot amass them together. In a word, as it does nothing, it must needs congregate nothing.

Aristotle judging of things by his Senses, imagin'd Cold to be as positive as Heat; and because the Sensations of Heat and Cold are both real and positive, he supposes them both likewise to be active Qualities: and indeed, if we follow the Impressions of the Senses, we shall be apt to be∣lieve that Cold is a very active Quality; since cold Water congeals, accumulates, and hardens in a moment melted Gold and Lead, when they are pour'd upon it from a Crucible; though the Heat of those Metals be yet strong enough to separate the Parts of the Bodies which they touch.

'Tis plain, by what has been said in the First Book, concerning the Errours of the Senses, That if we relye upon the Judgment the Senses make of the Qualities of sensible Bodies, 'tis impossible to discover any certain and undeniable Truth, that may serve as a Principle to proceed in the Knowledge of Nature. For one cannot so much as discover that way, what things are hot, and what cold; amongst several Persons, who touch luke-warm Water, it feels cold to those that are hot, and hot to those that are cold. And if we suppose Fishes susceptible of Sensation, 'tis very probable that they feel it warm, when all or most Men feel it cold. It is the same with Air, that seems to be hot or cold, according to the different Dispositions of the Bodies of those that are ex∣posed to it. Aristotle pretends that it is hot, but I fansie that the Nothern Inhabitants are of ano∣ther Opinion, since several learned Men, whose Climate is as hot as that of Greece, have asser∣ted it to be cold. But that Question, which has made so much noise in the Schools, will never be resolv'd, as long as no distinct Idea shall be affixed to the Word Heat.

The Definitions Aristotle lays down of Heat and Cold cannot settle that Idea. For Instance, Air, and even Water, though never so hot and scalding, congregate the parts of melted Lead to∣gether with those of any other Metal whatsoever. Air conglutinates all sorts of Fat joyn'd with Gums, or any other solid Bodies. And he shall be a very formal Peripatetick, who should think of exposing Mastich, to the Air, to separate the pitchy from the Earthy part, and other com∣pound Bodies to uncompound them. And therefore Air is not hot, according to the Definition

which Aristotle gives of Heat. Air separates Liquors from the Bodies that are imbued with them, hardens Clay, dries spread Linen, though Aristotle makes it moist, and so is hot and drying, ac∣cording to the same Definition; therefore it cannot be determined by that Definition, whether or no Air is hot. It may indeed be asserted that Air is hot in reference to Clay, since it separates the Water from the Earthy Part. But must we try all the various Effects of Air upon all Bodies, before we can be assured, whether there is Heat in the Air we breath in? If it be so, we shall ne∣ver be sure of it, and 'tis as good not to philosophize at all upon the Air we respire, but upon some certain pure and elementary Air, not to be found here below, of which we can very dog∣matically assert, with Aristotle, that it is hot, without giving the least Proof of it, nor even distinctly knowing what we understand either by that Air, or by the Heat ascribed to it. For thus we shall lay down Principles scarce to be destroyed; not because of their Plainness and Certainty, but by reason of their Darkness, and their being like to Apparitions, which cannot be wounded, because they have not a Body.

I shall not insist upon Aristotle's Definitions of Moisture and Dryness; it being evident, that they explain not their Nature. For according to those Definitions, Fire is not dry, since it is not easily contained within its own limits; and Ice is not moist, since it keeps within its proper Bounds, and can difficultly be adapted to external Bounds. But if fluid be understood by the Word humid, or moist, it may again be said, that Ice is not moist; and that Flame, melted Gold, and Lead, are very humid. If by humid or moist be understood what easily cleaves to any thing, Ice is not humid, and Pitch, Fat, and Oil, are moister than Water, since they cleave to Bodies more strongly than it does. Quick-silver is moist in that sense, for it cleaves to Metals; where∣as Water is not perfectly moist, since it cleaves not to most of them. So that 'tis unserviceable to have recourse to the Testimony of the Senses, to defend the Opinions of Aristotle.

But without farther examining his wonderful Definitions of the four Elementary Qualities, let us suppose that whatever the Senses teach us of those Qualities is incontestable: let us muster up all our Faith, and believe all those Definitions very accurate: Only let it be allowed us to en∣quire whether all the Qualities of sensible Bodies are made of these Elementary Qualities. Aristo∣tle pretends it, and he must do so indeed, since he looks upon those Four primitive Qualities, as the Principles of all the things which he intends to explain in his Books of Physicks.

He teaches us, that Colours are produced from the Mixture of those Four Elementary Quali∣ties; White is produced when Moisture exceeds Heat; as in old Men, when they grow gray; Black when Moisture is exhausted, as in the Walls of Cisterns; and all other Colours by the like Mixtures: that Odours and Savours arise from different Degrees of Dryness and Moisture, mix'd together by Heat and Cold; and that even Gravity and Levity do depend thereon. In short, All sensible Qualities must needs be produced, according to Aristotle, by Two active Principles, viz. Heat and Cold: and composed of Two passive, namely, Dryness and Moisture; that there may be some probable Connexion betwixt his Principles, and the Consequences he draws from them.

However 'tis yet a harder Task to persuade us of such things, than any of those that have been hitherto related from Aristotle. We can scarce believe that the Earth, and other Elements, would not be colour'd, or visible, if they were in their natural Purity, without Mixture of those Ele∣mentary Principles, though some learned Commentators on that Philosopher assert it. We under∣stand not what Aristotle means when he assures us, that gray Hair is produced by Moisture, because in old Men Moisture exceeds Heat; though to illustrate his thought we put the definition instead of the thing defined. For it looks like an incomprehensible piece of Nonsence to say that the Hair of old Men becomes gray, because what is not easily contained within its own Limits, but may be within others, exceeds what congregates homogeneous things.

And we are as hard put it to believe that Savour is well explain'd, by saying it consists in a mixture of Dryness, Moisture, and of Heat, especially when we put, instead of those words, the Definitions given by that Philosopher; as it would prove useful, if they were just and good. And none perhaps could forbear laughing, if instead of the Definitions which Aristotle gives of Hunger and Thirst when he says, that Hunger is the desire of what is hot and dry, and Thirst the desire of what is cold and moist; we should substitute the Definitions of those words, calling Hunger the desire of that which coacervates things of the same nature, and is easily contained with∣in its own Limits, and difficultly within others; and defining Thirst, the desire of that which con∣gregates things of the same and different natures, and which can hardly be contained within its own bounds, but is easily kept within others.

Surely 'tis a very useful Rule to know whether Terms have been well defined, and to avoid mistakes in reasoning, often to put the Definition instead of the thing defined; for that shews whe∣ther the words are equivocal, and the Measures of the Relations false and imperfect, or whether we argue consequently. If it be so, what Judgment can be made of Aristotle's Arguments, which become an impertinent and ridiculous Nonsence, when we make use of that Rule? and what may also be said of all those who argue upon the false and confused Ideas of the Senses, since that Rule which preserves Light and Evidence, in all exact and solid Reasonings, brings nothing but confusion in their Discourses?

'Tis not possible to lay open the foolish Capriciousness and Extravagance of Aristotle's Expli∣cations upon all sorts of matters. When he treats of simple and easie Subjects, his Errours are plain and obvious to be discover'd; but when he pretends to explain very composed things and depending on several Causes, his Errours are as much compounded as the Subjects he speaks of; so that it is impossible to unfold them all, and set them before others.

That great Genius, who is said to have so well succeeded in his Rules for defining well, knows not so much as which are the things that may be defined, because he puts no Distinction betwixt a clear and distinct▪ and a sensible Knowledge, and pretends to know and explain other things of which he has not so much as a distinct Idea. Definitions ought to explicate the Nature of things, and the words of which they consist must raise in the Mind distinct and particular Notions. But 'tis impossible to define in that manner sensible Qualities, as Heat, Cold, Colour, Savour, &c. When you confound the Cause with the Effect, the Motion of Bodies with the Sensation that attends it; because Sensations being Modifications of the Soul, which are not to be known by clear Ideas, but only by internal Sensation as I have explain'd it in the third Book; it is impos∣sible to fix to those words, Ideas which we have not.

As we have Distinct Ideas of a Circle, a Square, a Triangle, and therefore know distinctly their Nature, so we can give good Difinitions of them, and even deduce from our Ideas of those Figures all their Properties, and explain them to others by such words as are fixed to those Ideas. But we cannot define either Heat or Cold, in as much as they are sensible Qualities, because we know them not distinctly, and by Ideas; but only by Conscience and inward Sensation.

Neither must we define the Heat that is without us by any of its Effects. For if we substitute such a Definition in its place, we shall find that it will only conduce to lead us into Errour. For In∣stance, if Heat be defined what congregates homogeneous things, without adding any thing else, we may by that Definition mistake for Heat such things as have no Relation to it. For then it might be said, that the Loadstone collects the Filings of Iron, and separates them from those of Silver, be∣cause 'tis hot; that a Dove eats Hempseed when it leaves other Grain, because that Bird is hot; that a covetous Man separates his Guineas from his Silver, because he is hot. In short, there is no impertinency, but that Definition would induce one into it, were he dull enough to follow it. And therefore that Definition explains not the nature of Heat, nor can it be imploy'd to deduce all its properties from it: since by literally insisting upon it, we should draw ridiculous Conclu∣sions; and by putting it instead of the thing defined, fall into Nonsense.

However, if we carefully distinguish Heat from its Cause; though it cannot be defined, in as much as it is a Modification of the Soul, whereof we have no Idea: yet its Cause may be defi∣ned, since we have a distinct Idea of Motion. But we must observe that Heat▪ taken for such a Motion, causes not always in us the Sense of Heat. For Instance, Water is hot, since its Parts are fluid, and in Motion, and most probably it feels warm to Fishes, at least 'tis warmer than Ice, whose Parts are more quiet; but 'tis cold to us, because it has less Motion than the Parts of our Body; what has less Motion than another, being in some manner quiet, in respect of that. And therefore 'tis not with reference to the Motion of the Fibres of our Body, that the Cause of Heat, or the Motion that excites it, ought to be defined. We must, if possible, define that Motion ab∣solutely, and in it self: for then our Definition will be subservient to know the Nature and Proper∣ties of Heat.

I hold not my self oblig'd to examine farther the Philosophy of Aristotle, and to extricate his so much confus'd and puzling Errours. I have shewn, methinks, that he proves not the Existence of his four Elements, and defines them wrong; that his Elementary Qualities are not such as he pre∣tends, that he knows not their Nature, and that all the Second Qualities are not made of them; and lastly, that though we should grant him that all Bodies are compos'd of the four Elements, and the Second Qualities of the First, his whole System would still prove useless for the finding out of Truth, since his Ideas are not clear enough to preserve Evidence in all our Reasonings.

If any doubt whether I have propos'd the true Opinions of Aristotle, he may satisfie himself by consulting his Books of the Heavens, and of Generation and Corruption, whence I have ex∣extracted almost all that I have said of him. I would relate nothing out of his Eight Books of Physicks, because some learned Men pretend they are but a mere Logick; which is very apparent, since nothing but rambling and undetermin'd Words are to be found in them.

As Aristotle often contradicts himself, and that almost all sorts of Opinions may be defended by some Passages drawn out of him, I doubt not but some Opinions, contrary to those I have ascrib'd to that Philosopher, may be prov'd out of himself: And I shall not warrant for him; but it is sufficient for me that I have the Books I have quoted, to justifie what I have said of him; and I care little whether those Books are Aristotle's, or not; taking them for such, as I find them upon the publick Fame; for we ought not to trouble our selves with enquiring into the true Genealogy of Things, for which we have no great Esteem.

CHAP. VI.

General and necessary Directions to proceed orderly in the Search after Truth, and in the Choice of Sciences.

LEST it should be said, that we have only been destroying the Reasonings of others, but establish nothing certain and undeniable of our own; it will be convenient to propose, in few words, what Order we ought to observe in our Studies, for the avoiding Errour: and I de∣sign withal to shew some Truths and Sciences that are very necessary, as bearing such a Character of Evidence, as that we cannot withold our Consent, without feeling the secret Upbraidings of

our Reason. I shall not explain at large those Truths and Sciences; that's already done, and I intend not to reprint the Works of others, but only to refer to them, and to shew what Order we must keep in our Studies, to preserve Evidence in all our perceptions.

The first Knowledge of all, is that of the Existence of our Soul; all our Thoughts are so many undeniable Demonstrations of it, for nothing is more evident, than that whatever actually thinks, is actually something. But though it be easie to know the Existence of our Soul, yet her Essence and Nature are not so easily discovered. If we desire to know what she is, we must take care above all, not to confound her with the things to which she is united. If we doubt, will, argue; we must only believe, that the Soul is something that doubts, wills, argues, and nothing more, as long as we have not felt in her other Properties: for we know our Soul only by the inward Sensation we have of her. We must not mistake her for our Body, for Blood, for Animal Spi∣rits, for Fire, and many other things for which Philosophers have mistaken her. We must be∣lieve of the Soul no more than we are forced to believe of her, by a full conviction of our in∣ward Sense, for otherwise we shall be deceiv'd. Thus we shall know, by a simple view, or by internal Sensation, whatever may be known of the Soul; without being obliged to long reason∣ings that might lead us into Errour. For when we reason, Memory operates; and whereever Memory operates, there may be Errour; supposing our Knowledge should depend on some wicked Spirits that should take delight in deceiving us.

Though I should suppose, for instance, a God, who took delight in thus abusing me; yet I am persuaded that I could not be deceived in a Knowledge of simple Perception, as is that by which I know that I am, that I think, or that 2 and 2 are 4. For I am conscious to my self, that in this extravagant Supposition, such a deluding Spirit, though never so potent, could not make me doubt that I am, or that 2 times 2 are 4; because I perceive those things with a simple view or Perception, and without the use of Memory. But when I reason, as I see not evidently the Principles of my Reasonings, but only remember that I have evidently seen them. If that sedu∣cing God should join that Remembrance to false Principles, as he might do if he pleas'd, I should conclude nothing but what was false. Just like those that make long Calculations; fancying they remember that they have plainly seen that 9 times 9 are 72, or that 21 is a primitive Num∣ber, or some other Errour of that Nature, draw false Inferences from thence.

And therefore 'tis necessary to know God, and to be assured that he is no Deceiver; if we de∣sire to be fully convinced that the most certain Sciences, as Arithmetick and Geometry are true Sciences; for without that their Evidence is not full, and we can still with-hold our Consent. And 'tis likewise necessary to know by a simple View, and not by Reasoning, that God is no De∣ceiver; since reasoning may still be false, in the supposition of a deluding God.

All the ordinary Proofs of the Existence and Perfections of God, drawn from the Existence and Perfections of his Creatures, are methinks liable to this Defect, that they convince not the Mind with a simple Perception. All those Arguments are Reasonings convincing in themselves; but be∣cause they are Reasonings, they are not demonstrative in supposing a wicked and deceitfull Genius. They sufficiently shew that there is a Power superiour to us, which is granted even by that foo∣lish Supposition: but they do not fully persuade us that there is a God, or a Being infinitely per∣fect; so that the Conclusion of those Arguments is more evident than the Principle.

Tis more evident that there is a Power superiour to us, than that there is a World, since no Supposition can obviate our demonstrating that superiour Power; whereas in supposing an evil and deceitfull Spirit, 'tis impossible to prove the Existence of the World: because it may still be conceived, that this wicked Genius gives us the Sense of things that are not in being; as Sleep, and some Distempers, make us perceive things that never were, and even feel an actual pain in imaginary Members, such as we have lost, or that we never had.

But the Arguments of the Existence and Perfections of God, drawn from our Idea of infinite, are Proo••s of simple sight. We see there is a God, as soon as we perceive infinite; because ne∣cessary Existence is included in the Idea of infinite, and that nothing but infinite can furnish to us the Idea of an infinite Being. We likewise see that God is no Deceiver, because knowing that he is infinitely perfect, and that infinite cannot want any Perfection, we plainly perceive that he will not seduce us, and even that he cannot, because he can but what he wills, and what he is able to will. And therefore there is a God, a true God, and a God that never deceives us; though he does not always enlighten us, and that we are obnoxious to Mistakes, when we want his Light. Attentive Minds perceive all those Truths, by a simple intuitive Perception, though we seem to make Arguments, that we may demonstrate them to others; so that they may be sup∣posed as unquestionable Principles of our Reasonings; for having known that God delights not in deceiving us, nothing hinders but we may proceed to Reason.

'Tis also plain that the certainty of Faith depends on that Principle, That there is a God un∣capable of Deceipt. For the Existence of God, and the Infallibility of his Divine Authority, are rather a natural Knowledge and common Notions, as to Minds capable of serious Attention, than Articles of Faith; though to have a Mind susceptible of a sufficient Attention rightly to conceive those Truths, and willingly to apply our selves to the understanding them, be a parti∣cular Gift of God.

From that Principle, That God is no Deceiver, we might likewise infer, that we have a real Body, to which we are united in a particular manner, and that we are surrounded with several others . For we are inwardly convinced of their Existence by the continual Sensations, which God produces in us, and which we cannot correct by Reason, without offending Faith; though

we can correct by Reason the Sensations that represent them, as endu'd with some Qualities and Perfections that are not in them: So that we ought not to believe that they are such as we see or imagine them, but only that they exist, and that they are such as we conceive them by Reason.

But that we may proceed orderly, we must not yet examine whether we have a Body, whether there are others about us, or whether we have only bare Sensations of Things which exist not. Those Questions include too great Difficulties, and are not perhaps so necessary as may be ima∣gin'd to perfect our Mind, and to have an accurate Knowledge of Natural and Moral Philoso∣phy, and some other Sciences.

We have within us the Ideas of Numbers and Extension, whose Existence is undeniable, and their Nature immutable; and which would eternally supply us with Objects to think on, if we de∣sire to know all their Relations: It is necessary to begin to make use of our Minds upon those Ideas, for some Reasons, which it will not be amiss to explain, whereof the principal are Three.

The First is, That those Ideas are the most clear and evident of all: For if, to avoid Errour, we must still keep to Evidence in our Reasonings, 'tis plain that we must rather argue from the Ideas of Numbers and Extension, than from the confus'd or compos'd Ideas of Physicks, Morals, Mechanicks, Chymistry, and other Sciences.

Secondly, Those Ideas are the most distinct and exact of all, especially those of Numbers: So that the Habit (which proceeds from the Exercise of Arithmetick and Geometry) of not being content till we precisely know the Relations of Things, endues the Mind with such an Exactness of Thought, as is not to be found in those that are satisfied with the Probabilities so obvious to be met with in other Sciences.

The Third and chief Reason is, That those Ideas are the immutable Rules and common Measure of all the Objects of our Knowledge: For those that perfectly know the Relations of Numbers and Figures, or rather the Art of making such Comparisons as are requisite to know them, have a kind of Universal Knowledge, and a very sure Means evidently and certainly to discover whatever goes not beyond the ordinary Limits of the Mind. But those that are not skilful in this Art, can∣not with Certainty discover such Truths as are somewhat intricate, though they have very clear Ideas of Things, and endeavour to know their Compound Relations.

These, or the like Reasons, mov'd some of the Antients to apply their Youth to the Study of Arithmetick, Algebra and Geometry. Undoubtedly they well knew that Arithmetick and Algebra endue the Mind with such an Insight and Penetration, as was not to be gotten by other Studies; and that Geometry manages the Imagination so well, as that it is not easily puzzl'd or confounded; for that Faculty of the Soul, so necessary to Sciences, acquires by the Use of Geometry, such an universal Nicety as promotes and preserves the clear View of the Mind, even in the most intricate Difficulties.

And therefore, he that desires always to preserve Evidence in his Perceptions, and discover na∣ked Tru••hs, without Mixture of Darkness and Errour, must begin with the Study of Arithmetick, Algebra and Geometry, after he has obtain'd some Knowledge, at least of himself, and the Sove∣reign Being. As for Books that make the Way to those Sciences easie, I may refer to the Medi∣tations of des Cartes, as to the Knowledge of God, and our selves; to the Elements of Mathema∣ticks, newly printed, as to Arithmetick and Algebra; to the New Elements of Geometry, printed in 1667, or to the Elements of Father Taquet, Jesuit, printed at Antwerp in 1665, as to ordi∣nary Geometry; and as to Conick Sections, and the Solution of Geometrical Problemes, to the Trea∣tises of Monsieur de la Hire, intituled, Of Conick Sections, Of Geometrical Places, and Of the Con∣struction of Equations; to which may be added, the Geometry of des Cartes.

I would not have advis'd to the Elements of Mathematicks, as to Arithmetick and Algebra, if I knew any Author who had clearly demonstrated those Sciences; but Truth obliges me to a thing, for which I may be blam'd by some People; for Algebra and Analyticks being altogether requisite for the Discovery of compos'd Truths, I must needs shew my Esteem for a Book which carries those Sciences very far, and which, in the Opinion of many Learned, explains them more clearly than they had been hitherto.

By the careful Study of those general Sciences, we shall evidently know a great Number of Truths, very serviceable in all accurate and particular Sciences. We may afterwards study Natu∣ral and Moral Philosophy, as being very useful, though no•• very fit to make the Mind nice and quick-sighted. And if we desire to preserve Evidence in all our Perceptions, we must take a spe∣cial Care not to be opinionated of any Principle that is not evident, and to which the Chinese, for instance, would not be suppos'd to dissent, after having throughly weigh'd and consider'd it.

And therefore we must only admit in Physicks those Notions which are common to all Men, such as Axioms of Geometry, and the clear Ideas of Extension, Figure, Motion, Rest, and others of that nature, if there be any. Perhaps it will be said, that Extension is not the Essence of Matter: But what is that to the purpose? 'Tis sufficient that the World, which we conceive to consist of Extension, appears like to that we see, though it be not made of such a Matter, which is good for nothing, and altogether unknown, whilst so much Noise is made about it.

It is not absolutely necessary to examine whether there are actually External Beings, corre∣sponding to those Ideas; for we argue not from those Beings, but from their Ideas. We must only take care that our Reasonings which we make upon the Properties of Things, agree with our inward Consciousness; that is, that our Thoughts perfectly agree with Experience; be∣cause in Physicks we endeavour to discover the Order and Connexion of Effects with their

Causes, either in Bodies if they exist, or in the Sense we have of them if they are not in being.

I say not, however, that we can doubt whether Bodies are actually existing, when we consider that God is not a Deceiver; and that the Order he has constituted in our Sentiments of Things▪ both as to natural Occurrences, and such as are wrought to create our Belief of what Reason is at a Loss to comprehend, is very regular. But I observe this, because 'tis not necessary to insist at first very long upon a thing which no body doubts of, and is not extremely conducible to the Knowledge of Physicks, consider'd as a true Science.

Neither must we puzzle our Heads with enquiring whether there are in the Bodies about us some other Qualities, besides those of which we have clear Ideas; for we must only reason up∣on our Ideas; and if there be any thing of which we have no clear, distinct and particular Idea, we shall never know it, nor argue from it with any Certainty: Whereas, perhaps, by reasoning upon our Ideas, we may follow Nature, and perhaps discover that she is not so hidden as is com∣monly imagin'd.

As those who have not study'd the Properties of Numbers, often imagine that it is not possible to resolve some Problemes, which are however simple and easie; so those that have not meditated upon the Properties of Extension, Figures and Motions, are very apt to believe, and even to assert, that most part of the Physical Questions are inexplicable. But we must not be deterr'd by the Opi∣nion of those who have examin'd nothing, or nothing at least with due Application: For though few Truths concerning Natural Things have been fully demonstrated, yet 'tis certain that there are some that are general which cannot be doubted of, though it be very possible not to think up∣on them, to know nothing of them, and to deny them.

If we meditate orderly, and with due Time and all necessary Application, we shall discover se∣veral of those certain Truths I speak of: But for more Conveniency, it will be requisite carefully to read des Cartes's Principles of Philosophy, without approving of any thing he says, till the Strength and Plainness of his Reasons shall suffer us to doubt no longer.

As Moral Philosophy is the most necessary of all Sciences, so it must be study'd with the great∣est Application; it being very dangerous to follow in this the Opinions of Men. But to the avoiding Errour, and keeping to Evidence in our Perceptions, we must only meditate upon such Principles as are confess'd by all those whose Hearts are not corrupted by Debauchery, and their Minds blinded with Pride: For there is no Moral Principle undeniable to Minds of Flesh and Blood, who aspire to the Quality of Bold Wits. Such People conceive not the most simple Truths; or if they do, they constantly deny them through a Spirit of Contradiction, and to keep up the Repu∣tation of great Wits.

Some of the most general Principles of Morality are, That God having made all things for him∣self, has made our Understanding to know, and our Will to love him: That being so just and powerful as he is, we cannot be happy but by obeying his Commands, nor be unhappy in follow∣ing them: That our Nature is corrupted, our Mind depending on our Body, our Reason on our Senses, and our Will on our Passions: That we are uncapable of performing what we plainly see to be our Duty, and that we have need of a Redeemer. There are yet many other Moral Prin∣ciples; as, That Retirement and Penitency are necessary to diminish our Union with sensible Ob∣jects, and to increase that which we have with intelligible Goods, true Goods, and the Goods of the Mind: That we cannot enjoy vehement Pleasures, without becoming Slaves to them: That nothing must be undertaken by Passion: That we must not long for Settlements in this Life, &c. But because these last Principles depend on the former, and on the Knowledge of Man, it behoves us not to take them at first for granted. If we orderly meditate upon those Principles, with as much Care and Application as so great a Subject deserves, and admit no Conclusion for true but such as follows from those Principles, we shall compose a very certain System of Morals, and per∣fectly agreeable with that of the Gospel, though not so large and compleat.

I grant that in Moral Reasonings it is not so easie to preserve Evidence and Exactness, as in some other Sciences; and that the Knowledge of Man being absolutely necessary to those that will proceed far, many Learners make no considerable Progresses therein: They will not consult themselves, to be sensible of the Weakness of their Nature: They are soon weary of interroga∣ting the Master, who inwardly teaches them his Will; that is, the Immutable and Eternal Laws, and the true Principles of Morality: They cannot listen with Pleasure to him that speaks not to their Senses, who answers not according to their Desires, and flatters not their secret Pride: They have no Veneration for such Words, the Lustre of which dazles not their Imagination, which are lowly pronounc'd, and never distinctly heard but when the Creatures are silent: But they consult with Pleasure and Reverence Aristotle, Seneca, or some new Philosophers, who seduce them by the Obscurity of their Words, by the Elegancy of their Expressions, or the Probability of their Reasons.

Since the Fall of our first Parents we esteem nothing but what refers to the Preservation of the Body, and the Conveniencies of Life; and as we discover that sort of Good by means of the Senses, so we endeavour to use them on all Occasions. The Eternal Wisdom, which is our true Life, and the only Light that can illuminate us, often shines but upon the Blind, and speaks but to the Deaf, when it speaks within the Recesses of our Soul, because we are for the most part exer∣cis'd abroad. And as we are continually putting Questions to the Creatures, to learn any News from them of the Good we are in search of, it was requisite, as I have said elsewhere, that this Wisdom should offer it self to our Senses, yet without going out of our selves, that we might learn by sensible Words and convincing Examples, the way to eternal Happiness. God perpetual∣ly

imprints on us a natural Love for him, that we may always love him; yet by that same Mo∣tion of Love we incessantly recede from him, running with all the strength he gives us to the sinsible Good which he forbids us to love; and therefore as he desires we should love him, so he must make himself sensible and offer himself before us, to stop by the delectation of his Grace all our restless Agitations, and begin our Cure by Sensations or Satisfactions, like to the preventing Pleasures that had been the Original of our Disease.

For these reasons I pretend not that Men may easily discover, by the strength of their Mind, all the Rules of Morality necessary to Salvation, and much less that they should be able to act accor∣ding to their Light; for their Heart is still more corrupted than their Mind. I only say, that if they admit nothing but evident Principles, and argue consequently from them, they shall discover the same Truths that are taught us in the Gospel: because it is the same Wisdom, which speaks imme∣diately, and by it self, to those that discover the Truth in evident Reasonings, and which speaks in the Holy Scriptures to those that understand them in their right sense.

We must therefore study Morality in the Gospel, to spare our selves the trouble of Meditation, and to learn with certainty the Laws and Rules of our Life and Manners. As to those who are not satisfied with a bare Certainty, because it only convinces the Mind, without enlightening it, they must meditate upon those Laws, and deduce them from their natural Principles; that they may know evidently by Reason what Faith has already taught them, with an absolute Certainty. Thus they will convince themselves, that the Gospel is the most solid Book in the World, that Christ perfectly knew the Disorders and Distempers of Nature, that he has rectified and cured them in a manner the most useful to us, and most worthy of himself, that can be conceived. But that the Light of Philosophers is nothing but a dark Night, and their most splendid Ver∣tues, an intolerable Pride: In short, that Aristotle, Seneca, and all the rest are but Men, to say nothing worse.

CHAP. VII.

Of the Vse of the First Rule concerning particular Questions.

WE have sufficiently insisted upon the general Rule of Method, more especially regarding the Subject of our Studies, and shewn, that Des Cartes has exactly followed it in his Sy∣stem of the World; whereas Aristotle and his Disciples have not observed it. We proceed now to the particular Rules that are necessary to resolve all sorts of Questions.

The Questions that may be formed upon all sorts of Subjects are of so many Kinds, as that it is not easie to enumerate them. However I shall set down the principal. Sometimes we search after the unknown Causes of some Effects that are known, and sometimes after unknown Effects by known Causes. Fire burns and dissipates Wood, we enquire after the Cause of it. Fire con∣sists in a violent Motion of the fiery Particles; we desire to know what Effects that Motion is able to produce, whether it may harden Clay, melt Iron, &c.

Sometimes we seek the Nature of a thing by its Properties, and sometimes its Properties by its Nature, that is known to us. We know, or suppose, that Light is transmitted in a mo∣ment; and however, that it is reflected and collected by a concave Mirrour, so as to consume and melt the most solid Bodies; and we design to make use of those Properties to discover its Nature. On the contrary we know, that all the space that reaches from the Earth to the Hea∣vens, is full of little Spherical and most movable Bodies, which continually endeavour their re∣moval from the Sun: We desire to discover whether the endeavour of those small Bodies may be transmitted in an instant; whether being reflected by a concave Glass, they must unite them∣selves, and dissipate or melt the solidest Bodies.

Sometimes we enquire after all the Parts of the Whole, and sometimes after the Whole by its Parts. We search after all the unknown Parts of a Whole that is known, when we seek all the Aliquot Parts of a Number, all the Roots of an Equation, all the Right Angles of a Figure, &c. And we enquire after an unknown Whole, all the Parts of which are known, when we seek the Summ of several Numbers, the Area of many Figures, the Dimensions of different Vessels. Or we seek a Whole, one Part of which is known, and whose other Parts, though unknown, include some known Relation with that which is unknown; as when we seek what is that Number, one Part of which, as 15, being known, makes with the other part the half, or the third of an unknown Number; or when we seek an unknown Number equal to 15, and to the double of the Root of that unknown Number.

Lastly, We often enquire whether some things are equal, or like to others; and how much they are unequal or different: As when we desire to know whether Saturn is greater than Jupiter, and how much the former surpasses the latter: Whether the Air of Rome is hotter than that of London, and how many degrees.

What is general in all Questions is, that they are formed for the Knowledge of some Truths; and because all Truths are Relations, it may generally be said, that in all Questions, we search but after the Knowledge of some Relations, either betwixt things, or betwixt Ideas, or betwixt things and their Ideas.

There are Relations of several sorts, as betwixt the Nature of things, betwixt their Magnitudes, their Parts, their Attributes, their Qualities, Effects, Causes, &c. but they may all be reduced to

two, viz. to Relations of Magnitude and of Quality; comprehending under the former, all those in which things are consider'd as suceptible of more and less; and all the others under the latter. So that it may be said, that all Questions tend to discover some Relation, either of Magnitude or of Quality.

The first and chief Rule is, That we must very distinctly know the state of the Question to be resolv'd; and have such distinct Ideas of its Terms, that we may compare them together, and discover their unknown Relations.

We must then first very clearly perceive the unknown Relation enquired after; for 'tis plain, that if we have no certain Mark to distinguish it, when 'tis sought for, or when 'tis found, our labour will be fruitless.

Secondly, We must, as far as possible, make the Ideas which answer to the Terms of the Que∣stion, distinct, by taking off their Equivocation; and make them clear, by considering them with all the possible Attention: for if those Ideas are so confused and obscure, as that we cannot make the necessary Comparisons, to discover the Relations we look for, we are not yet in a state of re∣solving the Question.

Thirdly, We must consider with all possible Attention, the Conditions expressed in the Question, if any there be; since without that we can but confusedly understand the state of that Question: besides that the Conditions commonly trace out the way to resolve it. So that when the state of a Question, and its Conditions are rightly understood, we not only know what we enquire after, but also sometimes by what means it may be discovered.

I grant that Conditions are not express'd in all Questions, but then those Questions are unde∣terminate, and may resolved several ways; as when 'tis required to find out a Square Number, a Triangle, &c. without specifying any other particulars: Or it may be that the Querist knows not how to resolve, or that he conceals them, in order to puzzle the Resolver; as when 'tis required to find out Two mean Proportionals betwixt Two Lines, without adding by the Intersection of the Circle and Parabola, or of the Circle and Ellipsis, &c.

And therefore 'tis altogether necessary, that the distinguishing Character of what is searched after, be very distinct, and not equivocal, or that it be only proper to the thing enquired; other∣wise we could not be certain whether the Question proposed is resolved. We must likewise care∣fully separate from the Question all the Conditons that make it intricate, and without which it subsists entire; because they fruitlessly divide the capacity of the Mind. Besides that we have not a distinct perception of the state of the Question, as long as the Conditions that attend it are useless.

Suppose, for instance, a Question were proposed in these Words; to cause that a Man be∣sprinkled with some Liquors, and crowned with a Garland of Flowers, be not able to rest, though he sees nothing that is capable of moving him. We must enquire whether the word Man is Meta∣phorical; whether the word Rest is equivocal; whether it relates to local Motions, or to Passions, as the last words, though he sees nothing that is capable of moving him, seem to hint: Lastly, We must enquire whether the Conditions, besprinkled with some Liquors, and crowned with a Gar∣land of Flowers are essential. Lastly, The state of that ridiculous and undeterminate Question be∣ing thus plainly known, 'twill be easie to resolve it, by saying that we need but put a Man in a Ship, with the Conditions expressed in the Question.

The Skill of those that propose such Questions, is to join some Conditions to them, that seem necessary though they be not so; that the Mind of the Resolver may be diverted to things that are unserviceable, as to the Solution of it. As in this Question, which Servant-Maids often put to Children; I have seen, say they, Hunters, or rather Fishers, which carried with them what they could not catch, and threw into the Water what they catch'd; the Mind being prepossessed with the Ideas of Fishers that take Fish, cannot understand the state of that Foolish Question; the whole Difficulty of which comes from hence, that we think not that Hunters and Fishers, as well as other Men, often seek in their Cloaths some little Animals, which they throw away if they catch, and carry with them if they find them not.

Sometimes all the Conditions that are necessary to resolve a Question are not mention'd, which makes them as hard as the expressing of unserviceable Characters, as in the following; to make a Man unmovable, without binding or wounding him; or rather, by putting his little Finger in∣to his Ear; so that he shall not be able to stir, until he takes his little Finger out of his Ear; that at first appears impossible, and 'tis really so: for any one may walk having his little Finger in his Ear; but there wants a Condition, which, if it were express'd, would remove the whole Diffi∣culty: for you need but make a Man embrace a Bed-post, or something like, and put his little Finger into his Ear, so that the Post be included between his Arm and Ear, it being plain he can∣not stir without taking out his Finger. It is not mentioned that there is yet something to be done, on purpose that the Mind should not seek for, nor discover it. But those that undertake the resolving of such Questions, must make all the Queries that are requisite, to understand the point wherein lies the Stress of the Difficulty.

Those arbitrary Questions appear to be foolish, and are indeed so in one Sense, as far as no∣thing is learn'd by their Solution. However they are not so different from natural Questions as may be imagin'd; for both are resolved by a Method that is very near the same. And as the Skill or Maliciousness of Men, makes arbitrary Questions intricate and difficult; so natural Effects are of themselves surrounded with Obscurity and Darkness, that must be dissipated by the Attention of the Mind, and by Experiments, which are a sort of Queries put to the Author of Nature;

even as Equivocations, and useless Circumstances are taken off from arbitrary Questions, by the skilful Queries that are made to the Proposers. Let us explain these things methodically, and in a more serious and instructing Manner.

There are many Questions which appear very difficult, because they are not understood, which should rather be taken for Axioms, that need some Explication, than for true Questions; for some Propositions which are undeniable, when the Terms that compose them are rightly understood, must not methinks be ranked in the Number of Questions.

For Instance, It is proposed as a very difficult Question, Whether the Soul be immortal; because they who propose, or pretend to resolve it, do not distinctly apprehend the Sense of the Terms. For as the Words Soul and immortal signifie different things, and that they know not how to un∣derstand them, so they cannot tell whether the Soul is immortal, having no distinct Idea, either of what they ask, or enquire after.

By the Word Soul may be understood a Substance that thinks, wills, feels, &c. or it may be taken for the Motion or Circulation of the Blood, and the Configuration of the parts of the Body; and lastly, for the Blood it self, and the Animal Spirits. Likewise by the Word immortal, we understand what cannot perish by the ordinary Force of Nature, or what cannot be changed; or lastly, what cannot be corrupted or dissipated, as a Vapour or Smoke. The Words Soul and immortal, being suppos'd thus distinguished into their several Significations, a very mean Atten∣tion of the Mind will be able to judge whether she is immortal or not.

First, 'tis plain that the Soul taken in the first Sense, or for a thinking Substance, is immortal, if you explain immortal in the first Sense, what cannot perish by the ordinary Force of Nature; since 'tis not conceivable, that any Substance should be annihilated, but that to conceive the Possibility of it, we must have Recourse to the Omnipotence of God.

Secondly, The Soul is immortal, taking immortal in the third Sense, for what cannot be cor∣rupted, nor resolved into Vapour, or Smoke; since 'tis evident, that what cannot be divided into several Parts, cannot be corrupted, nor resolved into Vapours.

Thirdly, The Soul is not immortal, taking it in the second Sense, for what is unchangeable; for we have convincing Proofs enow of the Alterations of our Soul, which feels one while Pain and another Pleasure, which often desires some things which she afterwards ceases to desire; which is united to a Body from which she may be separated, &c.

If the Word Soul be taken in some other Sense, it will be as easie to perceive, whether she is immortal, fixing a determin'd Sense to that Epithet. And therefore what makes such Questions difficult, is, that they are not distinctly understood, or that the Words, in which they are express'd are equivocal; so that they rather need Explication than Proof.

There are some People so dull, and others so fanciful, as that they always take the Soul for some Configuration of the Parts of the Brain, and for the Motion of the Spirits. 'Tis indeed impossible to prove that the Soul is immortal, and unperishable in that Sense, the contrary being evident: so that this is not a Question difficult to be resolved, but a Proposition which 'tis not easie to make some people apprehend; because they have not the same Ideas as we, and that they labour all they can not to have them, and to blind themselves.

When we are asked, whether the Soul is immortal, or any other Question whatsoever; we must first take off the Equivocation of Words, and know in what Sense they are understood, that we may distinctly conceive the State of the Question. If those that propose it are ignorant of the Signification, we must put Queries to them, in order to illuminate and determine them. If by these Queries we discover, that their Ideas are not agreeable with ours, 'tis in vain to answer them; for to answer one who imagines that a Desire, for instance, is nothing but the Motion of some small Particles call'd Spirits; that a Thought is but a Trace or an Image, which the Objects or those Spirits have left in the Brain; and that all the Reasonings of Men consist but in the various Situation of some little Corpuscles, which dispose themselves differently in the Head; to answer him, I say, that the Soul taken in his Sense is immortal, is to deceive him, or to appear ridicu∣lous to him; but to tell him that she is mortal, is, in some Sense, to confirm him in a very dangerous Errour: we must then reply nothing at all, but only endeavour to make him retire into himself, that he may receive the same Ideas that we have from him who is only able to enlighten him.

'Tis likewise a Question which seems pretty difficult, To know whether Beasts have a Soul; how∣ever the Equivocation being taken off, it is so far from being hard, that those who suppose they have one, and those that think they have none, are ignorantly at bottom of the same Opinion.

The Soul may be taken for something Corporeal, dispersed through all the Body, which gives it Life and Motion; or else for something Spiritual. Those that pretend Beasts have no Soul, understand it in the second Sense; for never any Man denied that there is in Animals something Corporeal, which is the Principle of their Life or Motion; since it cannot be denied even of Watches. On the contrary, Those who assert that Beasts have Souls, understand it in the first Sense; for few believe them endued with a Spiritual and Indivisible Soul: so that both Peripate∣ticks and Cartesians believe that Beasts have a Soul, or a Corporeal Principle of their Motion, and both think they have none, or that there's nothing in them Spiritual, and Indivisible.

And therefore the Difference betwixt the Paripateticks and Cartesians consists not in that the former believe Beasts have a Soul, and the latter deny it; but only in that the Aristotelians think that Beasts are capable of Pain and Pleasure, of perceiving Colours, hearing Sounds, and of all the other Sensations and Passions of Men; whereas the Cartesians are of a contrary Opinion.

The latter distinguish the Word Sensation, to take off the Equivocation. For instance, They say that when one is too near the Fire, the Parts of Wood strike against his Hand, vibrate the Fibres; which Vibration is communicated to the Brain, and determines the Animal Spirits con∣tained in it to disperse through the outward Parts of the Body, in such a manner as is fit to make them shrink in, or withdraw. They agree that all those things, or the like, may possibly be found in Animals, and that they actually are, as being Properties of Bodies: And the Peripa∣teticks dissent not from it.

The Cartesians add, that the Percussion or Vibration of the Fibres of the Brain in Men, is attended with a Sensation of Heat, and that the course of the Animal Spirits to the Heart, and other Viscera, is accompanied with a Passion of Hatred, or Aversion; which Sense and Passion of the Soul they deny to be in Beasts, whereas the Peripateticks assert, that Brute Animals feel that Heat as well as we do; that they have, as we, an Aversion to what is uneasie to them; and ge∣nerally, that they are capable of all our Sensations and Passions. The Cartesians do not think that Beasts are sensible of Pleasure or Pain, nor that they love or hate any thing; because they admit nothing in them but what is material, and believe not that Sensations and Passions may be Properties of any Matter whatsoever. On the contrary some Peripateticks esteem Matter capable of Sensation and Passion, when 'tis extremely subtle and refined; that Beasts may feel, by means of the Animal Spirits, that is to say, of a very subtle and fine Matter; and that our Soul is sus∣ceptible of Sensation and Passion, only because she is united to such a Matter.

And therefore to resolve that Question, Whether Beasts have a Soul, we must retire within our selves, and consider with all possible Attention our Idea of Matter: if we can conceive that Mat∣ter so and so figur'd, as square, round, oval, &c. is some Pain, Pleasure, Heat, Colour, Odour, Sound, &c. then we may assert that the Soul of Beasts, though never so material, is however capable of Sense; but if we cannot conceive it, we must not assert it; for we must assure no farther than we can conceive. And likewise if we conceive that Matter toss'd and extremely agi∣tated upwards, downwards, in a Circular, Spiral, Parabolical, Elliptick Line, &c. is any thing of Love, Hatred, Joy, Sorrow, &c. We may say that Beasts have the same Passions as we, but if we apprehend it not, we must not say it, unless we will speak without understanding our selves. But I am sure no Motion of Matter will ever be mistaken for Love, or Joy, by him that shall earnestly think upon it: So that to resolve that Question, Whether Beasts have Sense, we need only take off Equivocation, as those that are called Cartesians use to do; for then that Question will be made so simple and easie, as to be resolved with a little Attention.

'Tis true that St. Austin supposing, according to the common prejudice of Mankind, that Beasts have a Soul; which he never doubted of, as far as I can perceive, because he never seriously examin'd it in his Works: this great Man, I say, perceiving that it is contradictory to say, that a Soul, or a Substance which thinks, feels desires, &c. is material, believed that the Soul of Beasts was really spiritual and indivisible. He proves by very evident Reasons, that a Soul, or whatever has Sense, Imagination, Fear, Desire, &c. must needs be Spiritual; but I never observed that he produc'd any Reason to maintain that Beasts have Souls. He even cares not to prove it, because 'tis likely that scarce any body doubted of it in his time.

There being now Men, who endeavour wholly to free themselves of their Prejudices, and call in Question all Opinions that are not grounded upon clear demonstrative Reasonings: it has been call'd into doubt, whether Animals have a Soul susceptible of the same Sensations and Passions as ours; however there are still several Defenders of the ancient Prejudices, who pre∣tend to prove that Beasts feel, will, think, and argue, even as we do, though in a more im∣perfect manner.

Dogs, say they, know their Masters, love them, and patiently bear the Blows they receive from them, as judging it their best interest not to forsake them; but as to Strangers, they hate them so much as not to away with their Flatterings. All Animals love their Young; Birds, which build their Nests in the extremities of the Branches, sufficiently shew, that they are afraid lest some Creature should devour them: They judge those Branches too weak to bear their Enemies, though strong enough to support both their Young and their Nests. Even Spiders, and the vilest Insects, give some Intimations of an Intelligence that animates them: For one cannot but wonder at the conduct of a little Beast, which though it be blind, yet finds means to trapan in its Nets, others that have Eyes and Wings, and are so bold as to attack the biggest Animals we see.

I grant that all the actions that Beasts perform are certain indications of an Intelligence; for whatever is regular demonstrates it. A Watch shews the same; for 'tis impossible Chance should have composed its Wheels, but an understanding Agent must have ordered its Motions. We plant a Seed inverted, the Roots that were upward sink down into the Ground of themselves, and the Seminal Nib that was turn'd downwards endeavours to alter its Position, to break out: That intimates an Intelligence. That Plant produces Knots at certain Distances, to strenghen it self; it covers its Seed with a Skin that preserves it, and surrounds it with Prickles to defend it: This still denotes an Intelligence. In short, whatever we see done, either by Plants or by Animals, undoubtedly denotes an understanding Agent. All the true Cartesians agree to it, but they make Distinctions, to take away as much as possible, the Equivocation of Words.

The Motions of Beasts and Plants intimate an Intelligence, but that Intelligence is not Matter, and is much distinguished from Beasts, as that which disposes the Wheels of a Watch is distinguish∣ed from the Watch it self. For that Intelligent Being seems infinitely Wise, Powerful, and infinitely the same who has framed us in our Mother's Womb, and affords us a growth to which all the

attempts of our Mind and Will cannot add so much as a Span. And therefore there is in Beasts neither Understanding nor Soul, in the sense those Words are commonly taken. They eat with∣out pleasure, they cry without Pain, they grow without being conscious of it, they neither desire, nor fear, nor know any thing; and if they act in such a manner as intimates an Intelligence, it is because God having made them for a certain time, he has framed their Body in such a manner as that they machinally, and without Fear, shun whatever is able to destroy them. Otherwise it must be said, that there is more Understanding in the smallest Insect, or even in a little Seed, than in the most Ingenious Man; it being certain that there are in them more different Parts, and regular Motions, than we are able to know.

But as Men are used to confound all things, and imagine that their Soul produces in their Bo∣dies most or all the Motions and Changes which befal it, they fix to the Word Soul the wrong Idea of Former and Preserver of the Body. So that thinking that their Soul produces in them whatever is absolutely requisite to the Preservation of their Life, though she knows not so much as the Con∣texture of the Body which she animates, they judge that there must needs be a Soul in Beasts, to produce all the Motions and Changes which befall them, because they are so like those which oc∣cur in us. For Beasts are begot, fed, strengthened, as our Body: they eat, drink, sleep, as we do; because we are altogether like them, as to our Body: the only Difference betwixt us and them con∣sisting in this, that we have a Soul, and they have none. But our Soul frames not our Body, di∣gests not our Aliments, and gives no Motion and Heat to our Blood. She feels, wills, argues, and animates the Body, as to the Sensations and Passions that relate to it: but not by dispersing her self through our Members, to communicate Sense and Life to them; for our Body can receive nothing of what belongs to the Mind. Thence 'tis plain, that the Reason why we cannot resolve several Questions, proceeds from our not distinguishing, and even from our not thinking to distin∣guish the different significations of a Word.

'Tis true, that we distinguish sometimes, but we do it so ill, that instead of taking off the Equi∣vocation of Words by our Distinctions, we make them more perplexed and dark. For instance, when we are asked, whether the Body lives, how it lives, and in what manner the Rational Soul animates it. Whether the Animal Spirits, the Blood, and other Humours live; whether the Teeth, the Hair, and the Nails are animated, &c. we distinguish the Words, live and be animated, in living or being animated with a Rational, with a Sensitive, or with a Vegetative Soul. But that Distinction is only fit to perplex the Question; for those Words want an Explanation themselves; and perhaps the two last, Vegetative and Sensitive, are inexplicable and inconceivable in the Sense they are commonly understood.

If we desire to fix a clear and distinct Idea to the Word Life, we may say, That the Life of the Soul is the Knowledge of Truth, and the love of Good; or rather, that her Thoughts are her Life; and that the Life of the Body consists in the Circulation of the Blood, and the just Proportion and Mixture of Humours; or rather, that the Life of the Body is such a Motion of its parts as is fit for its Preservation. The Ideas fix'd to the Word Life being thus made plain, it will evident∣ly appear, First, That the Soul cannot communicate her Life to the Body, since she cannot make it think. Secondly, That she cannot give it the Life by which it is fed, grows, &c. since she knows not so much as what is requisite to digest our Aliments. Thirdly, That she cannot make it feel, since Matter is incapable of Sensation, &c. Thus all other Questions concerning that Subject, may be resolved without Trouble; provided the Words, in which they are express'd, excite clear Ideas; for if they raise confused and dark, it is impossible to solve them.

In the mean while, 'tis not always absolutely necessary to have Ideas that perfectly represent those things, the Relations of which we desire to examine. It is often sufficient to have but an initial or imperfect Knowledge of them, because we seek not always exactly to know their Re∣lations. I shall explain this more at large.

There are Truths or Relations of two Sorts; some are exactly known, and others but imper∣fectly. We exactly know the Relation betwixt such a Square, and such a Triangle, but have only an imperfect Knowledge of the Relation betwixt London and York. We know that such a Square is equal to such a Triangle, double or treble of it, &c. but we only know that London is big∣ger than York, without knowing precisely how much.

Moreover there are infinite Degrees of Imperfection in Knowledge; and no Knowledge is imper∣fect, but in reference to a more perfect. For Instance, We know that London is bigger than Lin∣coln's Inn ••ields, and that Knowledge is only imperfect, in Relation to another more exact, by which we might accurately know, how much London is larger than that open place contained in it.

There are therefore several sorts of Questions. First, There are some in which we seek a per∣fect Knowledge of all the exact Relations of two or several things betwixt each other.

Secondly, There are some in which we search after the perfect Knowledge of some exact Re∣lation betwixt two or several things.

Thirdly, There are some in which we enquire after the perfect Knowledge of some Relation nearly approaching to the exact Relation, that is betwixt two or more several things.

Fourthly, There are some in which we are content to find a general and indefinite Relation.

'Tis evident, First, That to resolve the Questions of the First sort, and perfectly to know all the exact Relations of Magnitude and Quality betwixt two or more things; we must have distinct Ideas perfectly representing them, and compare them together in all the possible manners. We may, for Instance, resolve all the Questions that tend to discover the exact Relations betwixt 2 and 8, because both Numbers being accurately known may be compared together, as much as is

necessary to know the exact Relations of their Magnitude and Quality. We may know that 8 is 4 times 2, and that 8 and 2 are even, but not square Numbers.

'Tis plain, Secondly, That to resolve Questions of the second sort, and accurately to know some Relation of Magnitude or Quality, which is betwixt two or more things; 'tis necessary and suffici∣ent distinctly to know those Faces by which they must be compared, to discover the enquired Relation. For Instance, to resolve such Questions as tend to discover some exact Relations be∣twixt 4 and 16, as that 4 and 16 are even and square Numbers, it's sufficient exactly to know that 4 and 16 can be divided into equal parts without Fractions, and that both are the product of a Number multiplied by it self; and 'tis to no purpose to examine what is their true Magnitude: It being plain, that to know the exact Relations of Quality betwixt things, a distinct Idea of their Quality is sufficient, without thinking on their Magnitude; and that to know the exact Relations of Magnitude, we need not search after the true Quality, an accurate Knowledge of their Mag∣nitude being all that is required.

Thirdly, It clearly appears that to resolve the Questions of the third sort, or to know some Relation very near approaching the exact Relation that is betwixt two or several things; it is enough nearly to know the Faces by which they must be compared, to discover the Relation re∣quired, whether it be of Magnitude or Quality. For Instance, I may evidently know that the √ 8 is greater than 2, because I may very near know the true Magnitude of the √ 8; but I cannot dis∣cover how much the √ 8 is greater than 2, because I cannot exactly find out the true Magnitude of the √ 8.

Lastly, 'Tis evident that to resolve the Questions of the fourth sort, or to discover general and un∣definite Relations, it is enough to know things in a manner propotion'd to the need we stand in of comparing them together, to find out the required Relation. So that 'tis not necessary to the Solu∣tion of all sorts of Questions, to have very distinct Ideas of their Terms, or perfectly to know the things expressed by those words. But our knowledge must be the more exact, as the Relations we search after are more accurate and numerous: For as we have said in imperfect Questions, im∣perfect Ideas of the things consider'd are sufficient to resolve them perfectly, that is, as far as they reach. And many Questions may be resolved even without any distinct Idea of their Terms; as when we are ask'd whether Fire is capable of melting Salt, hardning Clay, resolving Lead into Va∣pours, and the like, we understand perfectly those Questions, and may very well solve them, though we have no distinct Idea of Fire, Salt, Clay, &c. Because the Querists only desire to know, whe∣ther we are ascertained by sensible Experiments that Fire produces those Effects. And therefore may receive a satisfactory Answer, by a knowledge drawn from the Senses.

CHAP. VIII.

An Application of the other Rules to particular Questions.

QUestions are of two sorts, some are simple and others compound. The former may be solved by the bare Attention of the Mind to the Ideas of the words, in which they are expressed: but the Solution of the latter must be perform'd by comparing them to a third or to many other Ideas. We cannot find out the unknown Relations that are express'd in the Terms of a Question, by immediately comparing the Ideas of those Terms, since they can neither be joined nor compa∣red. We must then have one or several mean Ideas, that we may make such Comparisons, as are necessary to discover those Relations; taking a special Care that those mean Ideas be the more clear and distinct, as the Relations enquired after are more exact and numerous.

That Rule is but a Consequence of the first, but of an equal importance with it. For if ex∣actly to know the Relation of the things compared, it is necessary to have clear and distinct Ideas of them: It plainly follows from the same Reason, that we must have an accurate knowledge of the mean Ideas, by which we intend to make our Comparisons; since we must distinctly know the Relation of measure with each of the things measured, to find out their Relations. I shall give some Instances of it.

When we put a piece of Cork, or other small and light Vessel, in the Water, with a Load∣stone in it, and offer to the North Pole of that Stone the same Pole of another Magnet which we keep in our Hands, we presently perceive that the former Load-stone flies back, as though it were driven by a violent Wind. 'Tis requir'd to discover the Cause of that Effect.

'Tis plain that to render a Reason of the Motion of that Load-stone, it is not sufficient to know the Relations it has to the other; for we might perfectly know them all, and yet not understand how two Bodies could repel each other without meeting.

We must therefore examine what are the Things which we distinctly conceive capable, accord∣ing to the Course of Nature, of moving Bodies; for 'tis requir'd to find out the natural Cause of the Motion of a Load-stone, which is certainly a Body. And therefore we must not have re∣course to any Quality, Form, or Being, which by a clear Knowledge we cannot conceive capable of moving Bodies; neither must we ascribe their Effect to an understanding Agent, since we are not assur'd that Intelligences are the ordinary Causes of the natural Motions of Bodies, and know not so much as whether they can produce Motion.

We plainly know that it is a natural Law, that Bodies should move each other when they meet: We must then endeavour to explain the Motion of the Load-stone, by the Means of some

concurrent Body. 'Tis true that something besides a Body may move it; but as long as we have no distinct Idea of that Thing, we must not admit it as a proper Means to discover what is search∣ed after, nor to explain it to others; for to contrive a Cause which none clearly conceives, is not to give account of an Effect. We must not then trouble our selves to enquire whether there is, or is not any other natural Cause of the Motion of Bodies, besides the mutual Impulse; but rather suppose that there is none, and attentively consider what Bodies may meet with, and move that Load-stone.

We presently see that it is not mov'd by the Magnet we keep in our Hands, since it touches it not; but because 'tis mov'd only when that Magnet is brought near it, and that it moves not of it self▪ we must infer that it is mov'd by some small Effluviums, or little Bodies, that proceed from that Magnet, and are driven to the other Load-stone.

To discover those Corpuscles, we must not open our Eyes, nor nearly consider that Magnet; for our Senses might impose upon our Reason, and make us judge that nothing proceeds out of it, because we perceive it not. Perhaps we should not reflect that we see not the most impetuous Winds, nor several other Bodies that produce very surprizing Effects: We must then keep close to that clear and intelligible Means, and carefully examine all the Effects of a Load-stone, to disco∣ver how that Magnet may continually vent so many little Bodies, without diminishing; for the Experiments we shall make will discover, that the small Particles that evaporate at one side, im∣mediately re-enter through another; and will serve to explain all the Difficulties that may be ob∣jected against the Method of solving this Question. But it must be observ'd, that this Medium must not be forsaken, though we should not be able to answer some Objections proceeding from our Ignorance in several things.

If we desire not to examine why Load-stones remove from each other when their Poles of the same Name are in Opposition to each other, but rather why they approach and endeavour to unite together when the North Pole of one is opposite to the South Pole of the other, the Question will be more difficult, and one Medium alone will not be sufficient to resolve it; for it is not enough exactly to know the Relations betwixt the Poles of those two Load-stones, nor to have recourse to the Medium propos'd in the fore-going Question; for that Means seems only fit to hinder the Ef∣fect, whereof the Cause is sought for: Neither must we propose any of those Things that are not clearly known to be the natural and ordinary Causes of Corporeal Motion; nor evade the Diffi∣culty of the Question, by the rambling and uncertain Notion of an Occult Quality in Load-stones, by which they attract each other; for the Mind cannot conceive any such Attraction in Bodies.

The Impenetrability of Bodies plainly convinces us, that Motion may be communicated by Im∣pulsion; and Experience evidently proves, that it is communicated that way: But there is no Rea∣son, nor Experiment, that clearly demonstrates the Motion of Attraction; for when the true and certain Cause of the Experiments, which are alledg'd to prove that sort of Motion, is found out, it is visible that what appear'd to be done by Attraction, is produc'd by Impulsion. We must not therefore insist upon any other Communication of Motion but that effected by Impulsion, since this Way is sure, and undeniable; whereas all the others imaginable have at least some Obscurity in them. But though it might be demonstrated, that mere Corporeal Things have some other Prin∣ciples of Motion besides the Concourse of Bodies, this might not however be reasonably rejected, but must rather be insisted upon preferably to all others, it being the most clear, and most evident; and appearing so undeniable, that we may confidently assert, that it has always been receiv'd by all Nations and Ages in the World.

Experience shews, that a Load-stone, freely swimming upon the Water, draws towards that which we keep in our Hands when their different Poles are opposite to each other; we must then conclude, that the Load-stone upon the Water is driven to it. But as the Magnet we hold cannot drive the other, seeing this other approaches it, and that the free Load-stone only moves at the Pre∣sence of the other Magnet, 'tis plain that to resolve this Question by the receiv'd Principle of the Communication of Motions, we must have recourse to two Means at least.

[illustration]

The Load-stone c approaches the Magnet C, and therefore the surrounding Air drives it, since no other Body can do it; that's the first Means. The Load-stone c moves not, except at the Presence of the Magnet C; and therefore the Magnet C must needs determine the Air, to drive the Load-stone c; that's the second Means. 'Tis evident these two Means are absolutely necessary: So that now the whole Difficulty consists in joining those two Means together; which may be done two several Ways; either beginning by something known in the Air, that encompasses the Load-stone c; or by some∣thing known in the Magnet C.

If we know that the Parts of the Air are in per∣petual Agitation, as those of all fluid Bodies use to be, we shall not doubt but they continually strike against the Load-stone c, which they sur∣round; but because they strike it equally on all sides, they impel it one way no more than another,

as long as there is an equal Quantity of Air on all sides. It being so, 'tis easie to judge that the Magnet C hinders, lest there should be as much Air towards a as towards b, which cannot be done but by its diffusing some other Corpuscles betwixt C and c, and therefore there ex••ale such Particles ou•• of both Load-stones, which filling up that Space, and carrying away the Air about a, make the Load-stone c less press'd on that side than on the other; and it must by consequence approach the Magnet C, since all Bodies move towards the side on which there is the least Pressure or Re∣sistance.

But if in the Load-stone c, about the Pole a, there were not many Pores fit to receive the small Particles streaming out of the Pole B of the Magnet C, and too small to admit those of the Air, 'tis plain that those small Particles being more agitated than the Air, since they are to chase it from betwixt the Load-stones, they would drive the Load-stone c, and remove it from the Mag∣net C: Therefore, since the Load-stone c approaches to, or removes from the Magnet C, accord∣ing as they are oppos'd by different or the same Poles, we must needs infer that the Poles a and b of the Load-stone c are full of different Pores; otherwise, the small Particles issuing out of the Magnet C could not have a free Passage, without impelling the Load-stone c at the side a, nor would they repel it at the side b. What I say of one of these Load-stones, must be understood of the other.

'Tis plain that we always learn something by that Method of Arguing from clear Ideas, and un∣deniable Principles: For we have discover'd that the Air which environs the Load-stone c, was driven from thence by Corpuscles perpetually flowing out of the Pores of both Load-stones; which Corpuscles find a free Passage at one side, but are shut out at the other. If we desir'd nearly to discover the Bigness and Figure of the Pores of the Load-stone through which those Particles pass, we ought to make other Experiments; but that would lead us to Subjects which we intend not to trea•• of. The Curious may consult des Cartes's Principles of Philosophy: I only observe, as an Answer to an Objection which will presently be made against this Hypothesis; that is, Why those small Particles cannot re-enter through the Pores from whence they came? That besides that the Pores of the Load-stones may be suppos'd to be wrought like the Channelling of a Screw, which may pruduce the propos'd Effect; it may be said likewise, that the small Branches, of which those Pores are made, bend one way to obey and yield to the Motion of the entring Particles; whereas they stand on end, and shut them out another way: So that we must not be surpriz'd at this Dif∣ference betwixt the Pores of the Load-stone, for it may be explain'd in several manners, and the only Difficulty consists in chusing the best.

If we had endeavour'd to resolve the fore-mention'd Question, beginning with the Corpuscles that are suppos'd to stream out of the Magnet C, we should have found the same; and likewise discover'd that Air is compos'd of an infinite Number of Parts that are in a perpetual Motion, with∣out which it would be impossible that the Load-stone c could approach the Magnet C. I insist not on the Explication of this, because there is no Difficulty in it.

Here follows a Question more compound and complicate than the fore-going; for the Solution of which, 'tis necessary to make use of many Rules. 'Tis ask'd, Which may be the Natural and Mechanical Cause of the Motion of our Members.

The Idea of Natural Cause is clear and distinct when understood, as I have explain'd it in the former Question: But the Words, Motion of our Members, are equivocal and confus'd, because there are several such Motions; some being Voluntary, others Natural, and others Convulsive. There are also different Members in the Humane Body; and therefore, according to the first Rule, I must ask, Of which of these Motions the Cause is requir'd from me? But if the Question be left undetermin'd, and to my Discretion, I examine it after this manner.

I attentively consider the Properties of those Motions; and discovering at first that Voluntary Motions are sooner perform'd than Convulsive, I infer that their Cause is different, and therefore that I may and must examine the Question by Parts, for it seems to require a long Discussion.

I restrain then my self to consider only Voluntary Motions; and because several of our Members are employ'd about them, I content my self for the present with the Consideration of the Arm. I observe that it is compos'd of several Muscles, which are most or all in Action when we raise so••ething from the Ground, or remove it from one place to the other: But I only insist upon one, being willing to suppose that the others are very near fashion'd after the same manner. I inform my self of its Texture and Shape by some Book of Anatomy, or rather by the sensible Sight of its Fibres and Tendons, which I cause to be dissected in my presence, by some skilful Anatomist, to whom I put all the Queries which, in the sequel, may exhibit to my Mind a Medium to find out what I seek for.

After such a serious Consideration, I cannot doubt but the Principle of the Motion of my Arm depends on the Contraction of its Muscles which compose it. I am likewise content, lest I should puzzle my self with too many Difficulties, to suppose, according to the common Opinion, that this Contraction is perform'd by the Animal Spirits, which filling up the Ventricle of those Mus∣cles, may cause their Extremities to come nearer. Now the whole Question concerning Voluntary Motion is reduc'd to this Point; How the small Quantity of Animal Spirits which are contain'd in our Arm, may at the Command of the Will, so suddenly swell the Muscles, as to afford a sufficient Strength to list up an Hundred Weight, or more.

Upon an attentive Reflexion thereupon, the first Means that offers it self to the Imagination, is commonly that of a quick and violent Fermentation, like to that of Gun-powder, or of some Liquors fill'd with Volatile Salt, when they are mix'd with others that are Acid, or full of a

fixed Salt. A small quantity of Gun-powder is able, when kindled, to raise not only an Hun∣dred Weight, but even a Tower, and a Mountain. Earthquakes, that overthrow Cities, and shake whole Countries, proceed from Spirits kindling under the Ground, almost as Gun-powder▪ So that supposing in the Arm such a Cause of the Fermentation and Dilatation of the Spirits, it may be look'd upon as the Principle of that Force, by which Men perform so sudden and violent Motions.

But as we ought to mistrust those Means that are offer'd to the Mind by the Senses, and of which we have no clear and evident Knowledge, so we must not easily admit this; for it is not sufficient to give an Account of the Strength and Quickness of our Motions, by a Comparison: For this is both a confus'd, and imperfect Account; because we are here to explain a volunta∣ry Motion, and Fermentation is not so. The Blood is exceedingly fermented in Fevers, and we cannot hinder it: The Spirits are inflam'd and agitated in the Brain, but we cannot rule their Agitation, nor lessen it by our Desire. When a Man moves the Arm several Ways, a Thousand Fermentations, great and small, swift and ••low, ought to begin, and (what is harder to ex∣plain) to end likewise in a Moment, as often and as soon as it is desir'd, if this Hypothesis were true. Besides, Those Fermentations ought not to dissipate all their Matter, but need al∣ways be ready to take Fire. When a Man has walk'd Twenty Miles, how many Thousand times must the Muscles, employ'd in walking, have been fill'd and empty'd; and what a vast quantity of Spirits would be requir'd, if Fermentation should dissipate and deaden them so often? And therefore this Supposition is insufficient to explain such Motions of our Body as entirely depend upon our Will.

'Tis plain that the present Question may be reduc'd to this Problem of Mechanicks, To find ••ut by Pneumatick Engines a Means to overcome such a Force as an Hundred Weight by another Force, though never so small; as that of an Ounce Weight: And that the Application of that small Force may produce the desir'd Effect, at the Discretion of the Will. The Solution of that Problem is easie, and the Demonstration of it clear.

It may be solv'd by a Vessel which hath two Orifices, one of which is a little more than 1600 times larger than the other, in which the Pipes of two equal Bellows are inserted; and let a Force precisely 1600 times stronger than the other be apply'd to the Bellows of the larger Mouth, for then the Force 1600 times weaker shall overcome the stronger. The Demonstration of which is clear in Mechanicks, since the Forces are not exactly in a reciprocal Proportion with their Mouths; and that the Relation of the weaker Force to the smaller Mouth, is greater than the Relation of the stronger Force to the larger Mouth.

But to solve this Problem by an Engine which sets better before the Eyes the Effect of the Mus∣cles, than the Former: We must blow a little in a Foot-ball, and hinder the Air from going out with a Sucker; then put upon that Foot-ball, half full of Wind, a Stone of 5 or 600 weight; or having set it on a Table, lay on it a Board, and on that Board a huge Stone, or cause a heavy Man to sit upon the Board, allowing him to hold by something, that he may sit the faster upon the rising Foot-ball; for if you blow again into it only with the Mouth, it will raise the Stone that compresses it, or the Man that sits upon it. The Reason of this is, that the Mouth of the Foot-ball is so small, or at least must be suppos'd so, in comparison to the Capaciousness of the Foot-ball that withstands the Weight of the Stone, that by such means a very small, is able to over∣come a very great Force.

If we also consider that Breath alone is capable of violently driving a Leaden Ball through a long and strait Trunk, because the Strength of the Breath is not dissipated, but continually re∣new'd, it will visibly appear, that the necessary Proportion betwixt the Mouth and the largeness of the Foot-ball being suppos'd, Breath alone may overcome a very considerable Force.

If we therefore conceive that the whole Muscles, or each of the Fibres of which they are made, have, as this Foot-ball, a competent Capacity to admit Animal Spirits, that the Pores through which those Spirits flow are yet proportionably straiter than the Neck of a Bladder, or the Aper∣ture of the Foot-ball; that the Spirits are detain'd in, or driven through the Nerves, almost as the Breath through a Trunk; that the Spirits are more agitated than the Air of the Lungs, and dri∣ven with a greater Violence to the Muscles than it is in a Bladder; we shall perceive that the Mo∣tion of the Spirits which are dispers'd through the Muscles, can conquer the Force of the heaviest Weight we carry; and that if we cannot move other more ponderous, this Want of Strength pro∣ceeds not so much from the Spirits, as from the Fibres and Membranes of which the Muscles are compos'd, which would burst should we make too great an Effort. Besides, If we observe that by the Laws of the Union betwixt Soul and Body, the Motion of those Spirits, as to their Deter∣mination, depends on the Will of Man, we shall see that the Motion of the Arm must needs be vo∣luntary.

'Tis true that we move our Arm so readily, that it seems, at first sight, incredible that the Course of the Spirits into the Muscles should be so swift as to effect that Motion. But we ought to consider that those Spirits are extremely agitated, always ready to pass from one Muscle into another; and that a small quantity of that Spirituous Liquor may sufficiently swell them up, so as to move them, or to lift up from the Ground something very light: For we cannot raise great Weights very readily, because that Effort requires a great stretching and swelling of the Muscles, which cannot be perform'd by the Spirits that are in the neighbouring or Antagonist Muscles; and therefore some Time is requir'd to call in more Spirits to their help, and in such a Quantity, as that they may be able to withstand the Heaviness of the Weight. Thus we see that

those that are loaden cannot run, and that a ponderous thing is not lifted up from the Ground so readily as a Straw.

If we consider that those that are of a fiery Temper, or heated with Wine, are quicker than others; that amongst living Creatures, those whose Spirits are more agitated, as Birds, move swifter than those in which Blood is colder, as it is in Frogs; and that in some of them, as the Chamelion, the Tortoise, and some Insects, the Spirits are so little agitated, that their Muscles are not sooner fill'd than a Foot-ball would be by the Breath of a Man. All these things being well ob∣serv'd, may probably make our Explication acceptable.

But though that part of the Question propos'd which concerns Voluntary Motions be sufficient∣ly resolv'd, yet we must not assert that it is fully and perfectly, or that nothing else in our Body contributes to those Motions besides what has been mention'd; for most probably there are a Thou∣sand Springs that facilitate them, which will for ever be unknown, even to those who give a better Guess upon the Works of God.

The second Part of the Question to be examin'd concerns the Natural Motions, or those that have nothing extraordinary in them, as Convulsions have; but are absolutely necessary to the Pre∣servation of our Machine, and consequently altogether independent on our Will.

I first consider with all the possible Attention, what Motions have those Conditions, and whe∣ther they are perfectly alike: And as I quickly perceive that they are for the most part different from each other, lest I should perplex my self with too many things, I shall only insist upon the Motion of the Heart; which, of all the inward Parts, is the best known, and its Motions the most sensible. Whilst I examine its Construction, I observe two Things, amongst many others: First, That it is compos'd of Fibres, as the other Muscles: And Secondly, That there are two re∣markable Cavities in it: And therefore I judge that its Motion may be perform'd by means of the Animal Spirits, since it is a Muscle; and that the Blood ferments and dilates in it, since it has Cavities. The first of these Judgments is founded upon what I have said before: The second, upon the Heart's being much hotter than any other Parts of the Body; and that it diffuses Heat, together with Blood, into all our Members; and that those two Ventricles could neither be form'd, nor preserv'd, but by the Dilatation of the Blood: So that they are subservient to the Cause that has produc'd them. I can then give a sufficient Reason of the Motion of the Heart, by the Spirits that agitate, and the Blood that dilates it, during the Fermentation: For though the Cause I alledge of its Motion should not be true, yet I plainly see that it is sufficient to pro∣duce it.

It may be, that the Principle of Fermentation or Dilatation of Liquors is not so well known to all Readers, as that I may pretend to have explain'd an Effect, by generally shewing that it pro∣ceeds from Fermentation: But all particular Questions are not to be resolv'd by ascending to the first Cause, though that may be done too, and a true System on which all particular Effects depend, discover'd, provided we only insist upon clear Ideas. But that Way of Philosophizing is neither the exactest, nor yet the shortest.

To comprehend this, it must be observ'd that there are Questions of two sorts; in the first, it is requir'd to discover the Nature and Properties of some Thing; in the others, we only desire to know whether a Thing has such or such Properties; or if we know it has, we desire only to dis∣cover what is the Cause of them.

To solve the Questions of the first sort, we must consider Things in their Birth and Original, and conceive that they are always produc'd by the most simple and natural Ways: But the Solu∣tion of the others requires a very different Method, for they must be resolv'd by Suppositions; and then we must examine whether those Suppositions induce into any Absurdity, or whether they lead to any Truth plainly and clearly known.

For instance, We desire to discover the Properties of the Roulet, or some one of the Conick Sections: We must consider those Lines in their Generation, and form them by the most simple and least perplexing Ways; for that is the best and shortest Means to discover their Nature and Properties. We easily see that the Sub••endent of the Roulet is equal to the Circle whence it is form'd: And if we discover not many of its Properties that way, 'tis because the Circular Line that produces it is not sufficiently known. But as to Lines merely Mathematical, the Relations of which may be more clearly known, such as are Conick Sections; 'tis sufficient for the discover∣ing a vast Number of their Properties, to consider them in their Generation: Only we must ob∣serve, that as they may be produc'd by a Regular Motion several Ways, so all sorts of Generation are not equally proper to enlighten the Mind; that the most simple are the best; and that it of∣ten happens, notwithstanding that some particular Methods are fitter than others, to demonstrate some particular Properties.

But when it is not requir'd to discover in general the Properties of a Thing, but to know whe∣ther such a Thing has such a Property; then we must suppose that it actually enjoys it, and care∣fully examine the Consequences of that Supposition, whether it induces into a manifest Absurdi∣ty, or leads to an undeniable Truth, that may serve as a Means to find out what is sought for. That is the Method which Geometricians use to solve their Problems: They suppose what they seek, and examine what will follow of it; they attentively consider the Relations that result from the Supposition; they represent all those Relations that contain the Conditions of the Problem, by Equations, and then reduce those Equations, according to the usual Rules; so that what is unknown, is found equal to one or several Things perfectly known.

I say therefore, that when 'tis requir'd to discover in general the Nature of Fire, and of the dif∣ferent Fermentations, which are the most universal Causes of natural Effects, the shortest and su∣rest Way is to examine them in their Principle. We must consider the Formation of the most agi∣tated Bodies, the Motion of which is diffus'd into those that ferment. We must by clear Ideas, and by the most simple Ways, examine what Motion may produce in Matter. And because Fire and the various Fermentations are very general Things, and consequently depending upon few Causes, there will be no need of considering very long what Matter is able to perform when ani∣mated by Motion, to find out the Nature of Fermentation in its very Principle; and we shall learn withall several other Things, altogether requisite to the Knowledge of Physicks: Whereas he that would in such a Question argue from Suppositions, so as to ascend to the first Causes, even to the Laws of Nature, by which all things are form'd, would make a great many of them that should prove false and unprofitable.

He might perhaps discover that the Cause of the Fermentation is the Motion of an invisible Matter; communicated to the agitated Parts of Matter: For 'tis sufficiently known, that Fire and the various Fermentations of Bodies, consist in their Agitation; and that by the Laws of Nature, Bodies receive their immediate Motion only from their meeting with others that are more agita∣ted: So that he might discover that there is an invisible Matter, the Motion of which is commu∣nicated to visible Bodies by Fermentation. But 'tis morally impossible that he should ever, by his Suppositions find out how all that is perform'd; which however is not so hard to do, when we examine the Formation of Elements, or of Bodies, of which there is a greater Number of the same Nature; as is to be seen in Monsieur des Cartes's System.

The Third Part of the Question concerning Convulsive Motions, will not be very difficult to solve, if we suppose that there are in our Bodies Animal Spirits susceptible of Fermentation; and withall, Humours so piercing, as to insinuate themselves into the Pores of the Nerves, through which the Spirits are di••••us'd into the Muscles; provided always that we pretend not to determine the true Texture and Disposition of those invisible Parts that contribute to these Convulsions.

When we have separated a Muscle from the rest of the Body, and hold it by the two Ends, we sensibly perceive that it endeavours to contract it self when prick'd in the Middle. 'Tis likely that this depends on the Construction of the imperceptible Parts, of which it is made; which are as so many Springs determin'd to some certain Motions, by that of Compunction. But who can be sure he has found out the true Disposition of the Parts employ'd in the Production of that Mo∣tion; and who can give an uncontroverted Demonstration of it? Certainly that appears altogether impossible, though perhaps by long thinking we might imagine such a Construction of Muscles, as would be fit to perform all the Motions we know them to be capable of; we must not therefore pretend to determine the true Construction of the Muscles. However, because it cannot be rea∣sonably doubted, but that there are Spirits susceptible of some Fermentation, by the Mixture of a very subtile heterogeneous Matter; and that acriminious and pungent Humours may creep into the Nerves, that Hypothesis may be suppos'd.

Now to proceed to the Solution of the Question propos'd: We must first examine how many sorts of Convulsive Motions there are; and because their Number is indefinite, we must insist on the Principal, the Causes of which seem to be different: We must consider in what Parts they are made, what Diseases precede and follow them; whether they are attended with Pain, or free from it; and above all, what are the Degrees of their Swiftness and Violence; for some are ve∣ry swift and violent; others are very swift, but not violent; a third sort are violent, and not swift; and others again are free from both these Symptoms: Some finish and begin afresh perpetually, others keep the Parts rigid and unmoveable for some time; and others deprive us of their Use, and altogether deform them.

All this being well weigh'd, it will be no hard matter to explain in general, after what has been said concerning Natural and Voluntary Motions, how the Convulsive are perform'd: For if we conceive that some Matter, capable of fermenting the Spirits, mixes with those contain'd in a Muscle, it must needs swell up, and produce in that part a Convulsive Motion.

If that Motion may easily be resisted, 'tis a sign that the Nerves are not yet obstructed by any Humour, since we may empty the Muscle of the Spirits that have enter'd into it, and determine them to swell up the opposite Muscle. But if we cannot do it, we must conclude that pungent and piercing Humours have some part at least in that Motion: Even it may often happen that those Humours are the only Cause of Convulsions, since they may determine the Course of the Spirits to some certain Muscles, by opening some Passages that convey them, and shutting others: Be∣sides, that they may contract the Tendons and Fibres, by penetrating their Pores.

When a very ponderous Weight hangs at the end of a Rope, it may considerably be rais'd by only wetting that Cord; because the Particles of Water penetrating as so many little Wedges be∣twixt the Threads of the Rope, shorten it by dilating it: So the piercing and pungent Humours, insinuating into the Pores of the Nerves, contract them, stretch the Parts to which they are tied, and produce in the Body Convulsive Motions, that are extremely slow, violent and painful, and and often leave the Part sadly distorted for a long time.

As to the Convulsive Motions that are very swift, they are caus'd by the Spirits; but it is not necessary that those Spirits should receive any Fermentation; 'tis enough that the Conduits, through which they pass, be more open at one side than at the other.

When all the Parts of the Body are in their natural Situation, the Animal Spirits diffuse them∣selves equally and readily through them, according to the Necessities of the Machine, and faith∣fully perform the Orders of the Will. But when Humours disturb the Disposition of the Brain, alter or variously move the Apertures of the Nerves, or penetrate into the Muscles, they agitate their Springs; and the Spirits diffusing into those Parts after a new and unusual manner, produce extraordinary Motions, without the Consent of the Will.

However, we may often, by a strong Resistance, hinder some of those Motions, and insensi∣bly diminish the Traces that produce them, even when the Habit is wholly form'd. Those that look carefully to themselves, find little Difficulty in preventing Grimaces, unbecoming Gestures, and a sourish Countenance, though their Body have a Disposition to them; and may even con∣quer them when strengthen'd by Habit, but with a great deal more Difficulty; for such Disposi∣tions should always be oppos'd in their Birth, and before the Spirits have traced out a Way not easie to be stopp'd up.

The Cause of those Motions is often in the agitated Muscle, and proceeds from some pungent Humour, or fermenting Spirits; but we must judge that it is in the Brain, especially when the Convulsions agitate not one or two parts of the Body, but most or all; and withall, in several Diseases which alter the natural Constitution of the Blood and Spirits.

'Tis true, that one Nerve often having different Branches, which disperse through Parts of the Body very remote, as into the Face and Bowels, it sometimes happens that a Convulsion, the Cause of which lies in a Part to which some one of those Branches resorts, may have Communi∣cation with those to which other Branches reach, without proceeding from the Brain, and with∣out a Corruption of the Spirits.

But when the Convulsive Motions are common to most Parts of the Body, we must needs say, either that the Spirits ferment in a very extraordinary manner, or that the Order and Disposition of the Parts of the Brain is disturb'd, or that it proceeds from both Causes together. I shall not insist any longer upon this Question, because it grows so compound, and depending on so many things, when we enter into Particulars, that it cannot easily be made serviceable to a clear Expli∣cation of the Rules we have given.

There is no Science which may supply us with more Examples, to shew the Usefulness of those Rules, than Geometry, and especially Algebra, since these two Sciences make a perpetual Use of them. Geometry plainly discovers the Necessity always to begin with the most simple Things, and which include the least Number of Relations: It always examines those Relations by Measures that are clearly known; it takes off whatever is unserviceable to discover them; it divides into Parts Compound Questions, disposes those Parts, and examines them in order. In short, The on∣ly Fault to be found in this Science is, as I have observ'd elsewhere, that it affords no conve∣nient Means to abridge Ideas, and discover'd Relations: So that though it regulates the Imagina∣tion, and makes the Mind exact; yet it increases not its Extent very much, neither does it give a Capacity to discover very compound Truths.

But Algebra, continually teaching to abridge, and in the shortest Way imaginable, Ideas and their Relations, extremely improves the Capacity of the Mind; for nothing so compound can be conce••v'd in the Relations of Magnitudes, but the Mind may discover it in time by the Means it affords, when we know the Way that ought to be taken.

The fifth Rule, and the following, which speak of the Method of abridging Ideas, concern on∣ly that Science, for none else has a convenient Way of abridging them; so that I shall not insist upon their Explication. Those who have a great Inclination for Mathematicks, and desire to give their Mind all the Force and Extent it is capable of, and to put themselves into a State of disco∣vering, without a Tutor, an infinite Number of new Truths, will perceive, if they earnestly ap∣ply themselves to Algebra, that the Usefulness of that Science, as to the Enquiry after Truth, proceeds from its observing the Rules we have prescrib'd. But I must advertise, that by Algebra, I especially understand that which des Cartes and some others have made use of.

Before the Conclusion of this Book, I shall set down an Example somewhat at large, to shew the Usefulness of the whole Treatise: I shall represent by it the Advances of a Man who, in the Discussion of an important Question, endeavours to free himself from Prejudices; I shall at first make him fall into some Faults, that they may excite the Remembrance of what has been said else∣where: But at last, his Attention leading him to the Truth enquir'd after, I induce him speaking positively, and as one who pretends to have solv'd the Question he examin'd.

CHAP. IX.

The last Instance to shew the Vsefulness of this Treatise, wherein the Cause of the Vnion of Parts in Bodies, and withall, the Rules of the Communica∣tion of Motion, are examin'd.

BOdies are united together three different Ways, by Continuity, Contiguity, and in a third man∣ner, that has no particular Name; because it seldom happens, I shall call it by the general Term of Union.

By Continuity, or by the Causes of it, I understand somewhat or other which causes the Parts of a Body to hold so strongly together, that we must use violence to separate them; for which Reason they are look'd upon as a Whole.

By Contiguity I understand that, whatever it is, which makes me judge that two Bodies touch one another immediately, so as that there is nothing betwixt them; though I judge not that they are strictly united, because I may easily separate them.

By the third Word, Union, I understand something or other which makes two Glasses, or two Marble-Stones, whose surfaces are well rub'd and polished upon each other, to adhere together, so as that though they can easily be separated, by making them glide over one another, yet we find some resistance when we endeavour to do it in another manner.

Now these two united Glasses, or Marble-stones, cannot be said to be continuous, because they are not conceived as a Whole, since they may easily be separated some certain way. Neither is this a Contiguity, though it be something very like it, because those two pieces of Glass, or Mar∣ble, are strictly enough united, and even more than the Parts of soft and liquid Bodies, as those of Butter and Water.

These Words being thus explained, we must now enquire after the Cause that unites Bodies, and the difference betwixt Continuity, Contiguity, and the Union of Bodies, taken in this particu∣lar Sense: I shall first seek the cause of Continuity, or that, I don't know what, which unites the Parts of a Body, and links them so strictly together, that violence must be used to separate them, and that they are look'd upon as making together but one Whole. I hope that this Cause being found out, it will prove no hard task to discover the rest.

It seems now necessary to me, that this, I don't know what, which binds even the smallest Parts of that piece of Iron I hold in my Hands, should be something very powerful, since I must use a very great Force to break off a small Part of it. But am not I extremely mistaken, for may not that difficulty I find in breaking the least piece of this Iron, come from my Weakness, and not from the Resistance of the Iron? And indeed, I remember, I have formerly used a greater vio∣lence than I now do, to break a piece of Iron like this; and if I fell sick, it might happen that my utmost endeavours could not perform it. I see therefore that I must not judge absolutely of the firmness with which the Parts of Iron are joyned together, by the endeavours I make to dis-unite them, but only judge that they stick very strictly to each other in relation to my little Strength, or that they hang more firmly together than the Parts of my Flesh; since the Sense of Pain I feel in using too much Force advertises me, I shall sooner disunite the Parts of my Bo∣dy, than those of the Iron.

Thence I conclude, That as I am not absolutely strong nor weak, so Iron and other Bodies are not absolutely hard or flexible; but only in reference to the Cause that acts upon them. And that my Endeavours cannot be a Rule to measure the Degrees of Force, that must be used to overcome the Resistance and Hardness of Iron; since Rules must be unvariable; whereas those Endeavours vary, according to the Time, the plenty of Animal Spirits, and the Hardness of Flesh; for, af∣ter all, I cannot always produce the same Effects by the same Endeavours.

This Consideration frees me from a Prejudice, that made me imagine strong Bands to unite the Parts of Bodies, which Bands perhaps are not in being, and I hope it will not be unprofitable hereafter: for I am wonderfully apt to judge of all things with relation to my self, and to follow the Impressions of my Senses, of which I shall more carefully beware. But let us proceed.

Having thought some Time, and search'd with some Application, the Cause of this strict Union, without being able to discover it; I find my self inclin'd by my own natural Laziness, to judge, as several others do, that it is the Form of Bodies that preserves the Union betwixt their Parts, or the Friendship and Inclination they have for such as are alike to them: And to form other judge∣ments of like nature; nothing being more convenient than sometimes to suffer our selves to be se∣duc'd, and to become Learned on a sudden, with little Expence.

But I intend to believe nothing but what I know, nor to suffer my self to be cast down by my own Laziness, nor to yield to bare Glimpses. Let us therefore lay aside those Forms and Incli∣nations, of which we have no distinct and particular, but only confused and general Ideas, which methinks we only frame with reference to our Nature, and the Existence of which several Per∣sons, and perhaps whole Nations, do not own. But methinks I see the Cause of this strict Union of the Parts which make up hard Bodies, without admitting any thing in it, but what all the World grants; or at least, what all the World distinctly conceives to be possible. For every one distinctly conceives, that all Bodies are composed, or may be composed of small Parts: It may then be that some shall be crooked and branched, and be able, as many little Fetters, strongly to hold others; or that they shall be so intricated amongst each others Branches, that it will not be easie to disunite them.

I am so much the apter to yield to this Thought, as I see visible Parts of the gross Bodies, hold and bind one another this way. But I can scarce sufficiently mistrust my Prejudices and Impression of my Senses. I must therefore more strictly examine this Matter, and enquire after the Reason, why even the minutest and last solid Parts of Bodies, in short, even the Parts of every one of these little Bands, hang together: For they cannot be united by other smaller Bands; since I sup∣pose them to be solid. Or if I say they are united in that Manner, it will reasonably be ask'd, What unites these others together? and so in infinitum.

So that the Difficulty of the Question now is,

[illustration]

how the Parts of those little Fetters, or of those branched Parts, can be so strictly united as they are; A, for instance, with B, which I suppose to be Parts of a little Band: Or, which is the same thing, (Bodies being so much the more hard, as they are the more solid and less porous,) the Que∣stion at present is, to know how the Parts of a Co∣lumn being made of Matter without Pores, can be so strongly joined together, and compose a very hard Body; since it cannot be said that the Parts of this Column hang together by small Fetters; for being without Pores, they have no particular Figure.

I am again extremely apt to say, that this Column is hard by its Nature; or that the small Fetters, of which hard Bodies are made up, are Attoms, the Parts of which cannot be divided; as being the Essential and last Parts of Bodies, and essentially crooked, branched, or of a perplex'd Figure. But I freely own this is not solving the Difficulty, and that laying aside my Prejudices, and the Illusions of my Senses, I should be in the wrong, to have Recourse to an abstracted Form, and to embrace a Phantasm of Logick, for the Cause I enquire after. I mean, I should be in the wrong to conceive, as something real and distinct, the rambling or indefinite Idea of Nature or Essence; which expresses nothing but what is known to us; and so to take an abstracted universal Form for the Physical Cause of a real Effect: for there are Two things which I cannot too much mi∣strust. The first is, The Impression of my Senses; and the other, My Readiness to take abstract∣ed Natures, and general Ideas of Logick, for real and particular, by which two Principles of Er∣rour I remember to have been often seduc'd.

For to return to the Difficulty in hand; 'tis not possible to conceive how those little Fetters should be indivisible by their own Essence and Nature, nor consequently how they should be in∣flexible; since, on the contrary, I conceive them most divisible, nay, necessarily divisible by their own Essence and Nature. For the Part A is most certainly a Substance as well as B; and conse∣quently 'tis plain that A may exist without B, since Substances may exist without one another, otherwise they would be no Substances.

It cannot be said that A is no Substance; for 'tis plain that that is not a bare Mode, whereas every Being is either a Substance, or the Mode of a Substance. And therefore since A is not a Mode, it is a Substance, and may exist without B; and much more the Part A exists separately from B; so that this Fetter is divisible into A and B.

Moreover, if this Fetter were indivisible or crooked by its own Nature and Essence, there would happen a thing quite contrary to what we see by Experience; for not one Body could be broken. Let us suppose, as before, a Piece of Iron composed of many Fetters perplexed within one ano∣ther, and A a B b to be two of them; I say it will not be possible to disintangle them, and con∣sequently to break the Iron. For to break it, the Fetters that make it up must be bent, which however are supposed inflexible by their own Nature and Essence.

If they be not supposed inflexible, but only indivisible by their own Nature, the Supposition would be unserviceable for solving the Question. For then the Difficulty will be, Why those little Fetters obey not the Force that is used to bend a Bar of Iron? Neither must they be sup∣posed indivisible, if they be not supposed inflexible: For if the Parts of those Fetters could change their situation in reference to one another, 'tis visible that they might be separated; since there is no Reason why, if one part may be somewhat removed from the other, it could not be entirely re∣moved. And therefore whether these little Fetters are supposed indivisible or inflexible, the Que∣stion cannot be solved by that means: for if they be only supposed indivisible, a Piece of Iron must be broken without trouble; and if they be supposed inflexible, it will be impossible to break it; since the little Fetters that make up the Iron, being intricated within one another, it will be impossible to disintangle them. Let us therefore solve the Difficulty by clear and undeniable Principles, and find the Reason why that little Band has two Parts A B so firmly united to one another.

'Tis needful, I perceive, to divide the Subject of my Meditation into Parts, that I may examine it the more exactly, and with less Intention of Thought; since I could not at first, at a single view, and with the whole Attention I am capable of, discover what I enquired after. This I might have done at the beginning; for when the Subjects of our Meditation are somewhat abstruse, 'tis al∣ways the best way to consider them by parts, and not fruitlessly weary our selves with the vain Hopes of meeting happily with the Truth.

What I enquire after is, The Cause of the strict Union betwixt the minute Parts, that make up the little Fetter A B. Now I conceive only distinctly three Things that can be the Cause sought for, viz. The very Parts of that little Fetter, or the Will of the Author of Nature, or lastly invisi∣ble Bodies surrounding such little Bands. I might yet alledge, as the Cause of these things, the Form of Bodies, the Qualities of Hardness, or some occult Quality, the Sympathy betwixt Parts of the same Species, &c. but since I have no distinct Idea of those fine things, I neither must nor can ground my Reasonings thereupon: so that if I find not the Cause I search after, in those things of which I have distinct Ideas, I will not fruitlessly trouble my self with the Contemplation of

such rambling and general Notions of Logick; and shall forbear speaking of what I understand not. But let us examine the first of these things, that may be the Cause, why the Parts of that small Band are so firmly joined; viz. the very Parts of which it is made up.

When I only consider the Parts of which hard Bodies are composed, I am inclined to believe, That no Cement, which unites the Parts of that Fetter, can be imagin'd besides themselves and their own Rest: for of what Nature could it be? It cannot be a thing subsisting of it self, since all those minute Parts being Substances, for what Reason should they be united by other Substances but themselves? Neither can it be a Quality different from Rest; because there is no Quality more con∣trary to Motion, that may separate those Parts, but their own Rest: but besides Substances and their Qualities, we know not any other sorts of things.

'Tis true, that the Parts of hard Bodies remain united, as long as they are in Rest one by another; and that when they are once in Rest, they remain of themselves in the same state, as long as they can; but this is not what I enquire after, and I know not how too I came to mistake the Subject. I en∣deavour here to discover, why the Parts of hard Bodies have so great a strength, to remain in Rest one by another, that they withstand the Force that is used to move them.

I might however answer my self, that every Body has truly Force of continuing fix'd in its pre∣sent state, and that this Force is equal whether in Motion or Rest: But that the Reason why the parts of hard Bodies remain in Rest by one another, and that we can † difficultly move and sepa∣rate them, is our not imploying sufficient Motion to overpower the Rest. This is probable, but I am seeking Certainty, if it be to be found, and not bare Probability. And how can I know with Certainty, and Evidence, that each Body has this Force to continue in the state it's in, and that this Force is equal both as to Motion and Rest, since Matter on the contrary, seems indifferently passive to either, and altogether destitute of Force. Let us have recourse then with M. des Cartes to the Will of the Creatour, which is, it may be, that Force which Bodies seem to have in them∣selves, which is the second thing above mention'd, suppos'd capable of preserving the Parts of this little Fetter we speak of, so closely link'd to one another.

Certainly, 'tis possible that God may will every Body should remain in its present state, and that his Will should be the Force which unites their Parts to one another, as I otherwise know his Will to be the Moving Force which puts Bodies in Motion: For since Matter is incapable of moving it self, I have Reason, methinks, to conclude it is a Spirit, and even the Author of Nature, which puts it and preserves it in Motion, by preserving it successively in different places by his bare Will; in as much as an Almighty Being acts not with Instruments, and his Will is necessarily follow'd by Effects.

I acknowledge then, it's possible that God may will that every thing remain in its present state, whether it be Motion or Rest, and that his Will may be the natural Power, which Bodies have of remaining in the state they once have obtain'd. And if so, we must like M. des Cartes, measure that Power, conclude what ought to be the Effects of it, and give Rules for the Force and Communica∣tion of Motions upon the Collision of different Bodies, in proportion to their Magnitude; since we have no other way of coming to the knowledge of that general and immutable Will of God, who makes the different Power these Bodies have of acting upon, and resisting one another, consist in their different Magnitude and Swiftness.

But however, I have no infallible proof that God wills by a positive Will, that Bodies remain in Rest, and one would think it sufficient for God to will the Existence of Matter, not only to cause it to exist, but to exist in Rest.

The case is not the same with Motion, since the Idea of a Matter mov'd, certainly includes two Powers to which it is related, viz. that which created, and also that which mov'd it. But the I∣dea of a Matter in Rest, includes only the Idea of a Power which has created it, whilst there is no necessity of any other Power to put it in Rest, since if we barely conceive Matter, without think∣ing on any Power, we shall necessarily conceive it in Rest. Thus it is I conceive things: for I am to judge by my Ideas; and my Ideas tell me, Rest is but the privation of Motion. For God need but cease to will the Motion of a Body; to make its Motion cease, and to cause it to Rest.

But I remember I have heard from many very ingenious Persons, that Motion seem'd to them as much the privation of Rest, as Rest the privation of Motion. And some will not doubt to af∣firm, for Reasons I can't comprehend, that Motion seems rather a privation than rest. I do not distinctly call to Mind the Reasons they alledge: however this ought to make me suspicious, lest my Ideas should be false. For though most Men say what they please upon Subjects that seem of little moment, yet I have Reason to believe the Persons I speak of, were pleas'd to speak what they thought: wherefore I must still examine my Ideas more carefully.

To me it seems a thing of undoubted Certainty, and the Gentlemen before mention'd won't deny it, that 'tis the Will of God which moves Bodies. The Force then which that Bowl I see in Mo∣tion has, is the Will of God that moves it; what now is God requir'd to do to stop it? Must he Will, by a positive Will, that it should Rest? or is it sufficient to cease to will its Motion? 'Tis plain, that if God but cease to will the Motion of this Bowl, the cessation of its Motion, and consequently Rest will succeed the cessation of the Will of God. For the Will of God, which was the Force that moved the Bowl, desisting, that Force desists, and the Bowl will be no longer mov'd. Therefore the cessation of the moving Force produces Rest: Rest then has no Force to cause it; but is a bare privation that supposes no positive Will in God. Thus we should admit in God a positive Will without any Reason or Necessity, if we ascribed to Bodies any Force to remain in Rest.

But to overthrow this Argument if possible, Let us now suppose a Bowl at Rest, as before we suppos'd it in Motion, what must God do in order to agitate it? Is it enough that he ceases to will its repose? if so, I have hitherto made no advance; for that Motion will be equally the privation of Rest, as Rest of Motion. I suppose then that God desists to will the Rest of this Bowl; but supposing it, I see it not put in Motion; and if any others do, I desire them to inform me with what degree of Motion it is carried. Certainly 'tis impossible it should be mov'd, or have any degree of Motion: and 'tis impossible to conceive any degree of Motion in it, barely from our conceiving that God ceases to will it should be at Rest; because it goes not with Motion as it does with Rest. Motions are infinitely various, and are susceptible of more and less; but Rest being no∣thing, one cannot differ from another. One and the same Bowl which moves twice as fast at one time as at another, has twice as much Force, or Motion, at one time as at another. But it can∣not be said that the same Bowl has Rest double at one time to its Rest at another.

There must therefore be a positive Will in God, to put a Bowl in Motion, or to give it such a Force as it may move it self with: But he need only cease to will it should be mov'd, to cause its Motion to desist; that is, to make it Rest. Just as to the creating a World, it is not enough that God cease to will its non-existence, unless he likewise positively will the manner it shall exist in. But in order to annihilate it, there is no need of God's willing it should not exist, since God cannot will Nothingness by a positive Will, but barely, that he cease to will its Being.

I consider not here Motion and Rest, according to their relative Capacity; (for 'tis manifest that resting Bodies have as real Relations to those about them, as Bodies in Motion) I only conceive that Bodies mov'd have a moving Force, and that others at Rest have no Force at all to persevere in it; because the Relations of mov'd to the circumambient Bodies, perpetually changing, they need a continual Force to produce these Changes; it being indeed nothing but these Changes, that cause all that Novelty we observe in Nature; but there is no need of Force to do nothing. When the Relation of a Body to those surrounding it is constantly the same, there is nothing done; and the Continuance of that Relation, I mean the Action of the Will of God, which preserves it, is not different from that which preserves the Body it self.

If it be true, as I conceive, That Rest is but the Privation of Motion, the least Motion, or that of the least Body mov'd, will include a greater Force or power than the Rest of the greatest Body; and so the least Force, and the least Body, suppos'd to be mov'd in a Vacuum, against another never so great and bulky, will be capable of moving it; since the largest Body at Rest will have no power of resisting the least Body that shall strike against it. Therefore the Resistance which is made by the Parts of hard Bodies, to hinder their Separation, necessarily proceeds from some∣thing else than their Repose.

But 'tis necessary to demonstrate by sensible Experiments, what we have been proving by abstract∣ed Reasonings, to see whether our Ideas comport with the Sensations we receive from Effects. For it often happens that such Reasonings deceive us, at least will not convince others, and especially such as are prejudiced to the contrary. M. Des Cartes's Authority has such an influence upon some Mens Reason, that unless we prove all imaginable ways, that great Man in an Errour, we cannot disabuse them. What I have said will be readily admitted by such as are not prepossess'd with a contrary Opinion; and I perceive that I shall even be blam'd by them, for proving things which seem to them indisputable: However, the Cartesians well deserve our endeavours to content them. The others may pass over this Discourse, if they think it tedious.

Here then are some Experiments which sensibly demonstrate that Rest has no power to resist Motion, and which consequently evince, that the Will of the Author of Nature, which constitutes the Power and Force every Body has to continue in its present state, respects not Rest, but Mo∣tion only; since Bodies consider'd in themselves have no Force at all.

We daily see great Ships, whilst floating in the Water, mov'd with little Bodies striking against them. From which Experience I conclude, notwithstanding all the subterfuges of Monsieur des Cartes and the Cartesians, that if these great Bodies were in a Vacuum, they might be moved with much greater facility, since the Reason of a Vessel's being mov'd in the Water with some difficulty, is the resistance the Water makes to the imparted Motion; which in a void space will not be found. Now that which manifestly shews that Water resists the Motion impressed on the Vessel, is the cessation of its Motion some time after the Impulsion, which certainly would not happen, did not the Vessel lose its Motion, by communicating it to the Water; or if the Water yielded to its passage without any opposition; or lastly, imparted to it some of its own Motion. Therefore since a Vessel agitated in the Water, ceases by degrees to move, 'tis an infallible sign that the Water, instead of forwarding, as Monsieur des Cartes pretends, withstands its Motion; and consequently it would be infinitely easier to move a great Body in a Vacuum than in Water, since there would be no resistance on the part of surrounding Bodies. 'Tis evident therefore, that Rest has no Force to resist Motion, and that the least Motion contains more Power and Force then the greatest Rest; or at least, that we ought not to measure the Force of Motion and Rest, by the Proportion we find between the Magnitude of Bodies in those two States, as Monsieur des Cartes has done.

'Tis true, there is some reason to believe that the Vessel is mov'd, whilst in the Water, by rea∣son of the continual change which happen in the watery parts about it, though to us it seems not to change its place: And this has been an inducement to M. Des Cartes and some Persons to

believe, that 'tis not the bare Force of the impelling Agent which makes it advance in Water; but that having before receiv'd a great deal of Motion from the little parts of the surrounding Liquid, which press it equally on all sides, this Motion is only determin'd by the adventitious Motion of the impelling Body; so that what moves a Body in Water, could not do it in a Va∣cuum. And thus it is that M. Des Cartes and his Followers defend the Rules of Motion they have given us.

Let us suppose, for Example, a Piece of Wood of a Foot square, plac'd in a liquid Body, all the little parts whereof act and move against it; and because they press it equally on all sides, as well towards A as B, the piece of Wood stirs neither one way nor another: Now if I drive ano∣ther Piece of Wood of half a Foot against the former, on the side A, I see it advance forward; hence I conclude, that it might be mov'd in a Vacuum with less Force than that of the Piece that drives it, for the foregoing Reasons. But the Persons I speak of deny it, and answer, that the rea∣son of the greater Piece's advancing, when urg'd by the little one, is, that the latter unable to move it singly, being joyn'd with the parts of the agitated Liquid, determines them to drive it by im∣parting some of their Motion to it. But 'tis manifest that by this Answer, the Piece of Wood, when once mov'd, could never diminish its Motion; but must, on the contrary, perpetually increase it. For according to this Answer, the Piece of Wood is more driven by the Water to the side of A than B, therefore it must perpetually proceed; and because this Impulsion is continual, its Mo∣tion must constantly increase. But, as I have said, the Water is so far from facilitating its Mo∣tion, that it continually resists it; which resistance still lessening it more and more, at last makes it altogether insensible.

But I am now to prove that the Piece of Wood which is equally push'd by the little parts of the encompassing Water, has no Motion or Force at all, capable of moving it, though it continually changes its immediate place; and the Surface of the Water round it is different at different times. For if it be so that a Body equally press'd on all sides, as a Piece of Wood, be destitute of Motion, undoubtedly that foreign Force that strikes against it, must communicate it, since at the time of this Force's urging it on, the Water resists, and insensibly dissipates the impress'd Motion, caus∣ing it, by little and little, at last to cease.

It is certain, at least to those I speak to, that there is no more Motion in Nature at one time than another; and that Bodies at rest cannot be put in Motion, but by the Collision of some agi∣tated Bodies, which communicate their Motion to them. Whence I conclude, that a Body, which I suppose created perfectly at Rest in the midst of Water, will never receive any degree of Motion, from the little parts of the Water which surround it, and which strike continually against it, provided their Force be equal on all sides; because all these little parts which dash e∣qually against it on all sides, rebounding again with their whole Motion, communicate none of it; and consequently this Body ought to be consider'd as at Rest, and without any moving Force, though it continually changes its Situation.

Now the proof I have for the rebounding of these little parts, together with their whole Mo∣tion, is this; That otherwise the Water which touches this Body, must grow very cold, or even congeal'd, and become almost as hard as the Wood upon its Surface, since the Motion of the watry parts ought to be equally diffus'd into the little parts of the Body they encompass.

But that I may accommodate my self to the Patrons of M. Des Cartes's Opinion, I am willing to grant that we ought not to consider a Vessel on the Water as at Rest. I grant likewise, that all the parts of the environing Water are ••ubservient to the new Motion imprinted by the Wa∣terman, though it be but too visible by the decrease of the Boat's Motion, that they resist it more on the side where it makes, than on the other whence it is driven: Notwithstanding which supposition, I say, that of all the Parts of Water in the River, according to M. Des Cartes, there are none which can promote the Motion of the Vessel, except those which immediately touch it on the side it is driven on. For according to that Philosopher, The Water being fluid, all the parts that go to its Composition, act not conjointly against the Body we would move; but only those which touching it, conjointly bear upon it. But those which conjointly bear upon the Vessel, and the Boat's-man together, are twenty times more inconsiderable than the Boat. 'Tis plain therefore, from the Explication given by M. Des Cartes in this Article, concerning the difficulty we find to break a Nail between our Fingers, that a little Body is capable of moving one much bigger than it self. For in short, our Hands are not so fluid as Water; and when we would break a Nail, there are more parts that act jointly in our hands, than in the Water which pushes a∣gainst a Vessel.

But here's a more sensible Experiment. Take a Plank well smooth'd, or any other very hard Plain, drive in it a Nail half way, and set this Plain in a somewhat inclining posture; then place a Bar of Iron an hundred times thicker than the Nail, an Inch or two above it, and letting it slide down, it will not break it. Mean time it is observable, that, according to Des Cartes, all the parts of the Bar, as being hard and solid, act jointly upon the Nail. If therefore there were no other C••ment than Rest to unite the parts of the Nail, the Bar of Iron being an hundred times big∣ger, ought by the Fifth Rule of M. Des Cartes, and according to Reason, communicate somewhat of its Motion to the part of the Nail it fell upon; that is, to break it, and pass on, even though this Bar should slide with a very gentle Motion. Therefore we must seek some other Cause than the Rest of Bodies, that makes them hard, and capable of resisting the violence that is offer'd to break them, since Rest has no Force to withstand Motion: And I am persuaded these Experien∣ces are sufficient to evince, that the abstracted Proofs we have given are not false.

We must then examine the third Thing we supposed before might be the cause of the strict Union found between the Parts of hard Bodies; namely, an invisible Matter which surrounds them; and which being rapidly mov'd, pushes most violently the external and internal Parts of these Bodies, and constringes them in such a manner as requires greater strength to separate them, than has that invisible and extremely agitated Matter.

Methinks I might reasonably conclude, that the Union of the constituent Parts of hard Bo∣dies depends on an invisible Matter which surrounds and compresses them, since the two other things, supposed possible Causes of this union, have been discover'd not to be truly so. For since I meet with Resistance in breaking a Piece of Iron, which Resistance proceeds not from the Iron, nor the Will of God, as I think I have proved, it must necessarily proceed from some invisible Matter, which can be no other than that which immediately surrounds and compresses it. Ne∣vertheless, I shall give some positive Proofs of this Opinion, after I have more largely explain'd it by some Instance.

Take a Globe of any hard Metal, which is hollow within, and divided in two Halfs, join them together with a little Bond of Wax at the place of their Union, and then extract the Air: these two half Globes will be so firmly join'd to one another, that two Teams of Horses fastned to the Rings on the opposite sides of the Globe, shall not separate them, provided they be large in proportion to the Number of Horses; when yet if the Air be suffer'd to enter, one Man shall separate them with a great deal of Ease. From this Experiment 'tis easie to conclude, that what united the two Hemispheres to one another, was the Pressure of the surrounding Air upon their outward and convex Surface, whilst there was no Compression in their concave and inward parts; so that the Action of the Horses which drew the two Hemispheres on either side, could not con∣quer the Resistance made by innumerable little Parts of Air, by their pressing these two Halfs: But the least Force is capable of dividing them when the Air entring in the Copper Globe, drives against the Concave and inward Surfaces, as much as the external Air presses against the outward and convex.

Take, on the contrary, the Bladder of a Carp, and put it in a Vessel from which the Air is pump'd: this Bladder being full of Air, will crack and burst, because then there is no exteriour Air to resist that within the Bladder. 'Tis likewise for the same Reason I have given of the first Experiment, that two Glass or Marble Plains, ground and polish'd upon one another, so cling toge∣ther, that Violence must be us'd to separate them one way; because the two parts of the Marble are press'd and constring'd by the external Air that surrounds them, and are not so strongly press'd by that between. I might produce infinite other Experiments to prove that the gross Air which surrounds Bodies strongly unites their Parts: But what I have said is enough to give a distinct Explication of my Thoughts upon the present Question.

I say then, that what causes the Parts of hard Bodies and the little Fetters before-mentioned to hang so closely united to each other, is, there being other little Bodies infinitely more agitated than the course Air we breath, which bear against them, and compress them; and that which makes it so hard to separate them, is not their Rest, but the Agitation of these little surround∣ing Bodies. So that that which resists Motion is not Rest, (this being but the Privation of it, and has no Force at all,) but some contrary Motion.

This simple Exposition of my Opinion perhaps seems reasonable; yet I foresee, that many Persons will not easily be induc'd to yield to it. Hard Bodies make so great Impression on the Senses when they strike us, or when we use Violence to break them, that we are inclin'd to be∣lieve their Parts more strictly united than they really are. And on the contrary, the little Bodies which I have said encompass them, and to which I have ascribed the Force of causing this Union, making no Impression on our Senses, seem too weak to produce so sensible an Effect.

But to take away this Prejudice, which bottoms on the Impressions of our Senses, and on the Difficulty we find to imagine Bodies more little and agitated than those we daily see; 'tis to be consider'd, that the Hardness of Bodies is not to be measur'd with relation to our Hands, or the Endeavours we are able to make, which are different at different times. For indeed, if the great∣est Force of Men be nothing in comparison with that of the subtle Matter, we should be much to blame to believe, that Diamonds, and the hardest Stones, cannot derive their Hardness from the Compression of those little rapid Bodies which environ them. Now we may visibly discover how inconsiderably weak is Humane Force, if it be consider'd that Man's Power of moving his Body in so many manners, proceeds from a very moderate Fermentation of the Blood, which some∣what agitates the smaller Parts of it, and so produces the Animal Spirits. For 'tis the Agitation of these Spirits, which makes the Strength of the Body, and gives us the Power of making those Endeavours which we groundlesly regard, as something great and mighty.

But it must be observ'd, that this Fermentation of our Blood, is but a small Communication of that subtle Matter's Motion we have been speaking of. For all the Fermentations of visible Bodies are nothing but Communications of Motion from the Invisible, since every Body receives its Agitation from some other. 'Tis not therefore to be wonder'd if our Force be not so great as that of the same subtle Matter we receive it from. But if our Blood fermented as much in our Heart as Gun-Powder ferments, and is agitated when Fire is put to it; that is, if our Blood re∣ceiv'd as great a Communication of Motion from the subtle Matter, as Gun-Powder receives, we might do extraordinary things with a great deal of Ease; as break a Bar of Iron, overturn an House, &c. provided we suppose a competent proportion between our Members and our Blood so violently agitated. We must therefore rid our selves of our Prejudice, and not, following the

Impression of our Senses, imagine that the Parts of hard Bodies are so strongly united to one ano∣ther, because of the Difficulty we find to break them.

But if moreover, we consider the Effects of Fire in Mines, the Gravity of Bodies, and seve∣ral other natural Effects, which have no other Cause then the Commotion of these insensible Corpuscles, as is prov'd by M. Des Cartes in many places of his Works, we shall manifestly dis∣cover, that it does not exceed their Force, to unite and bind together the Parts of hard Bodies so powerfully as we find them. For in short, I fear not to affirm, that a Cannon-Bullet, whose Motion seems so extraordinary, receives not the thousandth part of the Motion of the subtle Matter which surrounds it.

My Assertion will not be doubted of, if it be consider'd, First, That the Gun-Powder is not all inflam'd, nor at the same instant: Secondly, That though it were all on Fire in the self-same Mo∣ment, yet it floats a very short time, in the subtle Matter; and Bodies swimming but a little while in others, can receive no great Motion from them; as may be seen in Boats when riding in a Stream, which receive their Motion by degrees. Thirdly, and principally, That each part of the Powder can receive but a collateral Motion, which the subtle Matter yields to. For Water only communicates to the Vessel the direct Motion which is common to all the parts of it, which Mo∣tion is generally very inconsiderable in respect of the others.

I might still prove to M. Des Cartes's Followers, the Greatness of the subtle Matter's Motion, by the Motion of the Earth, and the Heaviness of Bodies; from whence might be drawn very certain and exact Proofs, if that were necessary to my Subject. But in order to have one suf∣ficient Proof of the violent Agitation of the subtle Matter, to which I ascribe the Hardness of Bodies, it suffices (without seeing Des Cartes's Works) to read attentively what I have written in the second Chapter of the fourth Book, towards the End.

Being now deliver'd from our Prejudices, which induc'd us to believe our Efforts very potent, and those of the subtle Matter which surrounds and constringes hard Bodies, very feeble; being likewise satisfied of the vehement Commotion of this Matter, by what has been said of Gun-Powder; 'twill be no hard Matter to discover, that 'tis absolutely necessary that this Matter, act∣ing infinitely more on the Surface, than the Inside of the hard Bodies it encompasses and com∣presses, should be the Cause of their Hardness, or of the Resistance we feel when we endeavour to break them.

But since there are always many Parts of this invisible Matter passing through the Pores of hard Bodies, they not only render them hard, as I have before explain'd; but are also the Causes that some are springing, and elastical, that others stand bent, and others still are Fluid and liquid; and in short are the Cause not only of the Force which the Parts of hard Bodies have to remain close by one another; but of that likewise which the parts of fluid Bodies have to separate; or, which is the same thing, are the Cause of the Hardness of some Bodies, and the Fluidity of others.

But whereas 'tis absolutely necessary to know distinctly the Physicks of M. Des Cartes, the Fi∣gure of his Elements, and of the parts which constitute particular Bodies, to account for the stiffness of some and the flexibility of others, I shall not insist upon explaining it. Such as have read the Works of that Philosopher, will easily imagine what may be the cause of these things; whereas it would be a difficult task for me to explain it; and those who are unaquainted with that Author would have a very confus'd Notion of the Reasons I might offer.

Nor shall I stand to resolve a vast number of Difficulties which I foresee will be urg'd against what I have been establishing, because if those who propose them have no knowledge of true na∣tural Philosophy, I should but tire and confound them instead of satisfying them. But if they were Men of Science, I could not answer them without a long train of diagrams and reason∣ing. Wherefore I think it best to intreat those who shall find any Difficulty in what I have said, to give this Discourse a more careful perusal; not doubting but if they read it and consider it as they ought, all their Objections will fall to the Ground. But after all, if they think my Request inconvenient, let them sit still, there being no great danger in the Ignorance of the Cause of the Hardness of Bodies.

I speak not here of contiguity: for 'tis manifest that contiguous things touch so little, that there's always a good quantity of subtle Matter passing between them, which endeavouring to continue its Motion in a right Line hinders them from uniting.

As to the union found between two Marbles that have been polish't one upon another, I have already explain'd it; and 'tis easie to see, that though the subtle Matter passes constantly between the two parts, as close as they are yet the Air cannot get in; and therefore 'tis that which compresses and constringes the two parts together, and makes them so difficult to be disunited, unless we glide them over one another.

For all this it is manifest that the Continuity, Contiguity and Union of two Marbles would be one and the same thing in a vacuum: for neither have we different Ideas of them, so that it would be to talk without understanding our selves to make them differ absolutely, and without any regard to the surrounding Bodies.

I now come to make some Reflexions upon M. Des Cartes's Opinion, and the Original of his Errour: I call his Opinion an Errour, because I can find no sincere way of defending what he has said upon the Rules of Motion, and the Cause of the Hardness of Bodies towards the end of the second Part of his Principles in several places; and that he seems to have evidently prov'd the Truth of the contrary Opinion.

This great Man most distinctly conceiving that Matter could not naturally move it self, but that the moving Force of all Bodies was nothing but the general Will of the Author of Nature; and that therefore the Communications of their Motion upon their mutual Collision, must come from the same Will, yielded to be carry'd away with this Notion, That the Rules of the different Communication of Motions must be fetch'd from the Proportion found between the different Mag∣nitudes of Colliding Bodies; it being impossible to penetrate into the Designs and Will of God. And whereas he concluded that every thing had the Force to persevere in its present State, whether it were in Motion, or Rest, because God, whose Will constituted this Force, acts always in the same manner; he inferr'd that Rest had an equal Force with Motion. Thus he measur'd the Ef∣fects of the Power of Rest by the Greatness of the Body it resided in, as well as those of Motion: And hence he gave the Rules of the Communication of Motion which are seen in his Principles, and the Cause of the Hardness of Bodies, which I have endeavour'd to refute.

'Tis a hard matter not to submit to the Opinion of Monsieur des Cartes, when we contemplate it on the same side: For, once more, since the Communication of Motions proceeds only from the Will of the Author of Nature, and that we see all Bodies continue in the State they have once been put in, whether it be Motion or Rest, it seems that we ought to seek for the Rules of the different Communications of Motion upon the Concourse of Bodies; not in the Will of God, which is un∣known to us; but in the Proportion that is found between the Magnitudes of these same Bodies.

I do not therefore admire that Monsieur des Cartes should light upon this Notion; but I only wonder he did not correct it, when having push'd on his Discoveries, he found out the Existence, and some Effects of the subtile Matter which surrounds all Bodies.

I am surpriz'd to find him, in the 132d Article of the Fourth Part, attribute the Elastick Force of certain Bodies to the subtile Matter, and yet not ascribe to it their Hardness, and the Resistance they make to our Endeavours to bend and break them; but only to the Rest of their Parts. For I think it evident, that the Cause of the Elasticity and Stiffness of some Bodies, is the same with that which impowers them to resist the Violence that is us'd to break them: For indeed, the Force which is employ'd in breaking a piece of Steel, has but an insensible Difference from that which is us'd to bend it.

I mean not to multiply Reasons here, which one might give for the proving these things; nor to answer some Difficulties possible to be urg'd about Bodies which are not sensibly springing, and yet are difficultly bent: For all these Difficulties vanish, if we consider that the subtile Matter cannot easily make new Tracks in Bodies which break in bending, as in Glass and temper'd Steel; which it can easier do in such Bodies as are compos'd of branchy Parts, and that are not brittle, as in Gold and Lead: And Lastly, that there is no hard Body; but has some kind of Elaterium.

'Tis a hard matter to persuade one's self that Monsieur des Cartes did positively believe the Cause of Hardness to be different from that which makes the Elasticity; and what looks most likely, is, that he made not sufficient Reflexion on that matter. When a Man has for a long time medita∣ted on any Subject, and is well satisfied about that of his present Enquiry, he commonly thinks no farther on it; he believes that the Conceptions he had of it are undeniable Truths, and that it is needless to examine them any more. But a Man has so many Things in him which disrelish his Application, provoke him to precipitate Judgments, and subject him to Errour, that though his Mind remains apparently satisfied, yet it is not always well instructed in the Truth. Monsieur des Cartes was a Man, like us: No greater Solidity, Accuracy, Extent, and Penetration of Thought is any where to be met with, than in his Works, I confess; but yet he was not infallible: There∣fore 'tis very probable he remain'd so settl'd in his Opinion, from his not sufficiently reflecting that he asserted something in the Consequence of his Principles, contrary to it. He grounded it on ve∣ry specious and probable Reasons; but such notwithstanding, as being not capable of themselves to force his Consent, he might still have suspended his Judgment; and consequently, as a Philo∣sopher, he ought to have done it. It was not enough to examine in a hard Body, what was in it that might make it so; but he ought likewise to have thought on the invisible Bodies, which might give it Hardness; as he did at the End of his Philosophical Principles, when he ascrib'd to them the Cause of their Elasticity: He ought to have made an exact Division, and comprehensive of whatever might contribute to the Hardness of Bodies. It was not enough to have sought the Causes of it in the Will of God; he ought also to have thought on the subtile Matter, which sur∣rounds these Bodies: For though the Existence of that violently agitated Matter was not yet pro∣ved in the place of his Principles where he speaks of Hardness; it was not however rejected; he ought therefore to have suspended his Judgment, and have well remember'd that what he had written concerning the Cause of Hardness, and of the Rules of Motion, was fit to be revis'd; which I believe was neglected by him; or at least, he has not sufficiently consider'd the true Rea∣son of a thing very easie to be discover'd, and which yet is of greatest Consequence in Natural Phi∣losophy. I thus explain my self:

Monsieur des Cartes well knew that to the Support of his System, (the Truth of which he could not reasonably suspect,) it was absolutely necessary that great Bodies should always communicate some of their Motion to the lesser which they met with; and that the latter should rebound at the Encounter of the former, without the like Loss of their own: For otherwise, the first Element would not have all the Motion that is necessary above the second, nor the second above the third; and so all his System would be absolutely false, as is manifest to those who have a little consider'd it. But in supposing that Rest has Force to resist Motion, and that a great Body in Rest cannot be mov'd by another less than it self, though most violently striking against it, 'tis plain that great

Bodies must have much less Motion than an equal Mass of little ones, since they may always by that Supposition communicate their own Motion, but cannot always receive any from the lesser. Thus this Supposition being not contrary to all that Monsieur des Cartes had laid down in his Prin∣ciples, from the beginning, to the Establishment of his Rules of Motion, and according very well with the Consequence of these same Principles, he thought the Rules of Motion, which he believ'd he had demonstrated in their Cause, were sufficiently confirm'd by their Effects.

I agree with Monsieur des Cartes in the Bottom of the Thing, that great Bodies communicate their Motion much easier than the lesser; and that therefore his first Element is more agitated than the second, and the second than the third; but the Cause is manifest without recourse to his Sup∣position. Little and fluid Bodies, as Water, Air, &c. can but communicate to any great ones an uniform Motion, which is common to all their Parts. The Water of a River can only communi∣cate to a Boat a descending Motion, which is common to all the little Parts the Water is compo∣sed of; each of which Particles, besides its common Motion, has infinite others, which are par∣ticular. Which Reason makes it evident that a Boat, for instance, cannot have so much Motion as an equal Volume of Water, since the Boat can only receive from the Water a direct Motion, and common to all the Parts of it. If twenty Parts of a fluid Body drive against any other Body on one side whilst there are as many urging it on the other, it remains immoveable; and all the Par∣ticles of the surrounding Fluid it swims in, rebound without losing any thing of their Motion. Therefore gross Bodies, whose Parts are united one to the other, can receive only a circular and uniform Motion from the Vortex of the encompassing subtile Matter.

This Reason seems sufficient to give us to understand why gross Bodies are not so much agita∣ted as little ones; and that it is not necessary to the explaining these things, to suppose any Force in Rest to resist Motion. The Certainty of Monsieur des Cartes's Philosophical Principles cannot therefore be of Use in proving or defending his Rules of Motion. And we have Reason to be∣lieve that if Monsieur des Cartes himself had, without Prepossession, examin'd his Principles afresh, at the same time weighing such Reasons as I have alledg'd, he would not have believ'd the Effects of Nature had corroborated his Rules; nor have fallen into a Contradiction, in attributing the Hardness of hard Bodies only to the Rest of their Parts, and their Elasticity to the Effort of the subtile Matter.

I now come to give the Rules of the Communication of Motion in a Vacuum, which follow up∣on what I have before establish'd concerning the Nature of Rest. Bodies being not hard in a Va∣cuum, since they are only so by the pressure of the subtile Matter that surrounds them, if two Bo∣dies meet together, they would flatten without rebounding: We must therefore suppose them hard by their own Nature, and not by the pressure of the subtile Matter, to give these Rules.

Rest having no Force to resist Motion, and many Bodies being to be consider'd but as one at the Instant of their Collision, 'tis plain they ought not to rebound, save when they are equal in their Bulk and Swiftness, or that their Swiftness compensates for the Want of Bulk, or their Bulk the Want of Swiftness. And 'tis easie from hence to conclude, that they ought in all other Cases so to communicate their Motion, as afterwards to proceed along together, with an equal Pace.

Wherefore, to know what ought to happen in all the different Suppositions of the Magnitude and Celerity of Colliding Bodies, we need only add together all the Degrees of Motion of two or more, which ought to be consider'd but as one in the Moment of their Concourse, and afterwards divide the Summ of the whole Motion proportionably to the Bulk of each respective Body.

Hence I conclude, that of the † seven Rules of Motion, Monsieur des Cartes has given, the three first are good.

That the Fourth is false, and that B ought to communicate its Motion to C, in proportion to the bigness of the same C, and after go along in Company; so as if C be double to B, and B have three Degrees of Motion, it must give away two of them: For I have sufficiently prov'd, that Monsieur des Cartes ought not to have suppos'd in Rest, a Force to resist Motion.

That the Fifth is true.

That the Sixth is false, and that B ought to communicate half of its Motion to C.

And that the Seventh is false, and that B ought ever to communicate its Motion to C, in propor∣tion to the Magnitude and Motion of both B and C. But that if, according to the Supposition, C be double to B, and have three Degrees of Motion, whilst C has but two, they must proceed together in Company, C and B being but one Body at the time of their Collision; and therefore we must add together the Degrees of Swiftness, which are five, and afterwards divide them in proportion to their bigness, and so distribute 1 3/2 to B, and 3 ⅓ to C, which is double to B. But these Rules, though certain, from what I have said, are yet contrary to Experience, since we are not in a Vacuum.

The chief of those Experiences, which are contrary to what I have said about the Rules of Mo∣tion, is, the constant rebounding of hard Bodies, when they meet, one one way, and another an∣other; or at least, their not going in Company after their Encounter.

In Answer to which, we must call to mind what we have formerly said of the Cause of Elastici∣ty; namely, That there is a Matter, of a strangely-violent Motion, which continually passes into the Parts of hard Bodies, and makes them so by its compressing both their outward and inward Parts: For it will be easie from hence to see, that at the time of Percussion two encountring Bo∣dies drive and turn off the Current of this Matter from the places nearest to the stricken; which Matter resisting with great Violence, repells the two Bodies, which strike against each other, and restores its Passage, which the Percussion had stopp'd up.

That which more clearly still proves my Opinion is this, That if two Bowls of Lead, or of any other less Elastick Matter, meet, they rebound not after their Collision, but proceed almost ac∣cording to the Rules before establish'd, which they keep to so much more exactly as they are less springing. Bodies therefore rebound after their Percussion, because they are hard; that is, as I have explain'd, because there is an extremely agitated Matter, which compresses them, and which passing through their Pores with an extreme Violence, repel the Bodies which strike against them. But it ought to be suppos'd that the Percutient Bodies break not those which they dash against by a Motion over-powering the Resistance the little Parts of the subtile Matter are capable of making; as when we discharge a Musket against a piece of Wood.

'Tis true, the subtile Matter compresses soft Bodies, and passes with a rapid Course through their Pores, no less than through those of hard; and yet these soft Bodies have no Elasticity: The Rea∣son whereof is this; that the Matter passing through soft Bodies, can with a great deal of Ease open it self new Passages, by reason of the Minuteness of the Parts composing them, or of some other particular Configuration, proper for that Effect; which hard Bodies will not admit, by rea∣son of the Largeness and Situation of their Parts, which are contrary to the same.

Thus when a hard Body strikes another that is soft, it alters all the Roads the subtile Matter us'd to pass through, which is commonly visible; as in a Musket-Bullet, which flattens when it is smit∣ten. But when a hard Body strikes against another like it, it either makes none, or very few new Paths; and the subtile Matter in its Pores is oblig'd to return upon the same Ground, or else must repel the Body which blocks up its little Avenues.

Let A be a hard Body, B a soft one, C the Chanel

[illustration]

of the subtile Matter; I say, that if A strike B in the Point c, the Chanel Cc is shut up, and the subtile Mat∣ter finds out new Ways in the soft Body; and so ha∣ving an open Road, it repels not the striking Body, but the Body stricken changes its Figure, and batters it self a little: And it must be suppos'd, that in the least Body there are infinite Passages like Cc. But if the Bodies A and a are both of them hard, the Pas∣sage Cc is straiten'd; and the subtile Matter included in it continuing its Motion in a Right Line, for want of new Paths, repels the Body striking it so much more violently as it finds greater Difficulty in making a new Way; or else the Parts of the Body A break, and se∣parate from one another, and are reduc'd to Dust, or Pieces.

Lastly, It seems evident, that every mov'd Body, continually endeavouring to tend in a Right Line, and declining from it as little as is possible when it meets Resistance, ought never to rebound, since by that Motion it extremely deviates from a Right. 'Tis necessary therefore, either that Bodies should grow flat, or that the stronger should conquer the weaker, and make it bear it company: But because Bodies are springing, and hard, they cannot go in company, since if A pushes a, a repels A; and so they must recede from one another.

Notwithstanding, if two Bodies were in a Vacuum, though never so hard, they would go in company, because having no Body to surround them, they could have no Elastick Force, the Striker making no Resistance to the Striking; but Air, Gravitation, &c. resisting the great Motion which the striking Body gives the stricken, the stricken resists the striking, and hinders it from follow∣ing: For Experience teaches us, that Air and Gravity resist Motion; and that this Resistance is so much greater, as the Motion is more violent. 'Tis easie to discover from what I have been say∣ing, how it comes to pass, that in the Percussion of different Bodies, encompass'd with Air or Water, &c. sometimes the Smiting rebounds, sometimes communicates all its Motion, and re∣mains as it were unmoveable; and sometimes it follows the Smitten, but always with less De∣grees of Swiftness, if one or other of them be not perfectly soft: For all this depends on the Pro∣portion that is found between the Magnitude, the Hardness, and the Weight of one and the other, supposing them mov'd with an equal Swiftness: If they are very hard, the Smiting rebounds more, because the Elaterium is stronger. If the Smiting is very little, the Smitten very large and weigh∣ty, the Smiting rebounds still much, because of the Weight and the great Mass of Air surround∣ing the Smitten, which withstands the Motion. Last of all, If the Force of the Hardness is, as it were, abated by the little Volume of Air answering the Littleness of the stricken Body, or the contrary; it may happen that the Smiting may remain as immoveable after the Percussion. We need therefore but compare the Hardness of percutient Bodies, and the Air, which the Percuss'd ought to agitate anew at the time of Percussion, whereby to move, to give a pretty exact Con∣jecture concerning what must happen in the Percussion of different Bodies. I still suppose an equal Swiftness in the striking, for the Air more resists a great Motion than a little one; and there is as much Motion in a Body twice as little, as in another, when proceeding twice as fast as that other. Thus the Smitten being driven as fast again, may be consider'd as having a Volume of Air twice as big, to repel, in order to its moving.

But it ought still to be observ'd, that at the Moment of one Body's striking another, the Parts of this same Body have two contrary Motions; for those on the Fore-side have a backward Ten∣dency,

by reason of the Collision, when at the same time those behind tend forwards on the Ac∣count of the first Motion; and 'tis that Counter-motion which flattens soft Bodies, and is the Cause that some hard Bodies break in pieces; but when Bodies are very hard, this Counter-stroke, which vibrates some of the Parts, and makes a sort of Trepidation in them, as appears from the Sound they give, always produces some Changes in the Communication of Motion, which are very difficult to be known, for many Reasons; and 'tis, in my Mind, to little purpose to examine them in particular.

Would a Man meditate on all these things, I believe he would easily answer some Difficulties which might still be rais'd upon the Subject; but if I thought that what I have said were insuffi∣cient to shew that Rest has no Force to resist Motion, and that the Rules of the Communication of Motions, given by Monsieur des Cartes are in part false, I would here make out that it is impos∣sible by his Supposition to move our selves in the Air: And that which makes the Circulation of Motion in Fluid Bodies possible, without recurring to a Vacuum, is, that the first Element easily divides it self in several different manners, the Repose of its Parts having no Force to resist Motion.

The CONCLUSION of the Three last BOOKS.

I Have, if I mistake not, sufficiently shewn in the Fourth and Fifth Books, that Men's natural In∣clinations and Passions frequently occasion their falling into Errour; because they induce them more to a precipitate Judgment, than a careful Examination of Things.

I have shewn in the Fourth Book, that our Inclination for Good in general, is the Cause of the Restlesness of the Will; that this Restlesness of the Will puts the Mind in continual Agitation; and that a Mind continually agitated, is utterly unfit for the Discovery of any the least intricate and hidden Truths: That the Love of new and extraordinary Things frequently prepossesses us in their behalf; and that whatever bears the Character of Infinite, is capable of confounding our Ima∣gination, and mis-leading us. I have explain'd how our Inclination for Greatness, Elevation and Independency insensibly engage us in a falsly-pretended Learning, or in the Study of all vain and useless Sciences, which flatter the secret Pride of our Heart; because this is what recommends us to the Admiration of the Vulgar. I have shewn, that the Inclination for Pleasures constantly throws off the View of the Mind from the Consideration of abstracted Truths, which are the most simple and exuberant; and permits it not to consider any thing, with a competent Attention and Impartiality, to judge well of it: That Pleasures being the Modes of our Souls Existence, they necessarily divide the Capacity of the Mind; and that a Mind thus divided, cannot fully compre∣hend a Subject of any great Extent. Last of all, I have made appear, that the Relation and Natu∣ral Union we have to all those with whom we live and converse, is the Occasion of many Errours we fall into, and of our communicating them to others, as others communicate to us the same they were engag'd in.

In the Fifth, where I have endeavour'd to give some Idea of our Passions, I have, I think, made it sufficiently evident, that they were ordain'd to unite us to all things sensible; and to give us, as we are among them, a due and necessary Disposition for their Preservation and our own: That as our Senses unite us to our Body, and expand our Soul into all the composing Parts of it; so our Commotions carry us, as it were, out of our selves, and diffuse us upon all things round about us: That, Lastly, they incessantly represent things, not as they are in themselves, whereby we may form true Judgments; but according to the Relation they have to us, whereby to form Judg∣ments useful to the Preservation of our Being, and of those to whom we are either naturally or voluntarily united.

After having attempted the Discovery of Errours in their Causes, and the Deliverance of the Mind from the Prejudices it is subject to, I thought it was time at last to prepare it for the Search of Truth. Wherefore, in the Sixth Book, I have explain'd the Means which I thought most na∣tural for the increasing the Attention, and enlarging the Capacity of the Mind, by shewing the Use that might be made of its Senses, its Passions, and Imagination, to the giving it all the Force and Penetration it is capable of. After which, I have establish'd certain Rules, which must of ne∣cessity be observ'd for the Discovery of any Truth whatever: I have explain'd them by many Ex∣amples, that I might make them more sensible; and have chosen those which I thought most use∣ful, or that included more fecund and general Truths; that they might be read with greater Ap∣plication, and be made more sensible and familiar.

Possibly it may be acknowledg'd, by this Essay of Method which I have given, how necessary it is to reason only about clear and evident Ideas, and in which we are inwardly convinc'd that all Nations do agree; and never to proceed to Compound Things, till having sufficiently examin'd the Simple, whereon they depend.

And if it be consider'd that Aristotle and his Followers have not observ'd the Rules I have ex∣plain'd, as we ought to be assur'd by the Reasons I have alledg'd, and by the Correspondence that may be had with the most zealous Defenders of that Philosopher, it may be we shall despise his Doctrine, in spight of all the Impressions which persuade such as give way to be amuz'd by Words they do not understand.

But if we take notice of the manner of Monsieur des Cartes's Philosophizing, we cannot doubt of the Solidity of his Philosophy: For I have sufficiently shewn that he reasons but upon distinct and evident Ideas; beginning with most Simple Things, and afterwards passing on to the more Compound, which depend on them. Those who shall read the Works of that Learned Man, will have plenary Conviction of what I say of him, provided they read them with all the Application that is necessary to understand them: And they will feel a secret Joy, for being born in an Age and Country so fortunate, as to free them from the Trouble of seeking a Master to teach them Truth, among the past Ages of the Heathens; and in the Extremities of the Earth, among Bar∣barians and Strangers.

But as we ought not to be very sollicitous to know the Opinions of Men, even though we were otherwise assur'd they had found out Truth; so I should be very sorry if the Esteem I manifest for Monsieur des Cartes should prepossess any Man in his behalf, and make him sit down satisfy'd with reading and retaining his Opinions, without caring to be enlighten'd with the Light of Truth. This would be preferring Man before GOD, and consulting him in God's stead; and acquiescing in the obscure Answers of a Philosopher, which do not enlighten us, to avoid the Trouble of In∣terrogating by our Meditation Him who answers and enlightens us both together.

'Tis a mean and unworthy thing to become the Partizan of any Sect, and to look upon the Au∣thors of it as infallible. And thus Monsieur des Cartes, chusing rather to make Men Disciples of Truth, than Opinionated Followers of his Sentiments, expressly forewarns them, Not to take any thing he writes upon Trust, and to embrace nothing but what the Force and Evidence of Reason should constrain them to believe. He desires not, like some Philosophers, to be credited upon his Word: He ever remembers that he is a Man; and that disseminating his Light but by Reflexion, he ought to direct the Minds of those who would be illuminated by him, towards Him alone who can make them more perfect by the Gift of Understanding.

The principal Advantage that can be made of Application to Study, is, the rendring the Mind more accurate, more illuminated, more penetrating, and fit for the Discovery of all the Truths we desire to know. But such as read the Philosophers, with Design of remembring their Opinions, and factoring them to others, approach not Him who is the Life and Nourishment of the Soul: Their Mind grows blind and enervate, by their Commerce with such as can neither strengthen nor enlighten them: They are swell'd up with a spurious sort of Learning, the Weight whereof over∣whelms, and the Glittering blinds them; and fancying to themselves they are hugely learn••d when their Heads are cramm'd with the Opinions of the Antients, they forget that they become their Disciples who, St. Paul says, became Fools by usurping the Name of Wise. Dicentes se esse Sa∣pientes, stulti facti sunt.

The Method I have given will, if I mistake not, be highly advantageous to those who desire to make use of their Reason, or to receive of God the Answers he gives all those who can faithful∣ly consult Him: For I think I have said what is chiefly requir'd to corroborate and conduct the Attention of the Mind; which is, the natural Prayer we make to the true Master of all Men, in order to be instructed.

But because this Natural Way of Searching out Truth is very painful, and commonly impracti∣cable, except in the Resolution of Questions of little Use, the Knowledge whereof commonly more gratifies our Pride, than perfects our Understanding; I think it my Duty to say, (that I may profitably conclude this Work,) that the most expeditious and certain Method of discovering Truth, and uniting our selves to God in the purest and perfectest manner possible, is, to live as becomes true Christians; to follow exactly the Precepts of Eternal Truth, which unites it self with us, only to re-unite us with it: 'Tis to listen rather to the Dictates of our Faith, than Reason; and to tend to God, not so much by our natural Forces, which, since the Sin, are altogether languid and in∣active; as by the Assistance of Faith, by which alone God purposes to lead us into that immense Light of Truth which will dissolve and dissipate all our Darkness: For, in brief, 'tis much better, as good Men, to spend some Years in Ignorance of certain Things, and find our selves enlighten'd in a Moment, for ever; than by Natural Means, and abundance of Trouble and Application, pur∣chase a very imperfect Science, that shall leave us in Darkness to all Eternity.

Notes

• Ego enim ab anima h••c corpus animari non pu••o, nisi intentione ••acientis: nec ab isto quicquam illam pati arbitror, sed facere de illo, & in illo, tanquam subjecto divinitus dominationi suae. l. 6. Mu••c. c. 5. See also De quantit. Anim. c. 34.
• Amos 3.6.
• Psal. 33▪ 9.
• Haec est Religio Christiana, fratres mei, quae praedicatur per universum mundum horrentibus inimicis, & ubi vincuntur murmurantibus▪ ubi praevalent saevientibus; haec est Religio Christiana, ut COLATVR VNVS DEVS, NON MVLTI DII, QVIA NON FACIT ANIMAM BE∣ATAM NISI VNVS DEVS. Aug. Tr. 23. in Joan.
• By Equa∣tor I under∣stand the greatest Crooked Line which the Matter of the Vortex describes.
• That is, are driven towards the Cen∣tre of the Earth.
• Princ. Part. 3. §. 45.
• Sup. Ch. 4.
• 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉 and 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉 make a Pun in Greek, as in English Finis and finished. Thus that Philosopher proves, that an infinite Line is not perfect, because 'tis not finished.
• De Coelo, l. 3. c. 3.
• L. 2. & 3. de Gene. & Corrup.
• De Gener. & Corrupt▪ l. 2. c. 2.
• See Book I. from ch. 11. ••o ch. 15.
• See Illu∣stration X. of Book I.
• Lib. 4. de Anima & ejus Origi∣ne. Cap. 23. de quanti∣tate Animae & alias.
• M. Des Cartes his Principles, Art. 55. Part. II.
• Art. 43. ibid.
• †

  Art. 63.
• Art. 33. Part. II.
• I imagine here only God, my self, and one Bowl.
• By a Bo∣dy in a Va∣cuum, I un∣derstand one so se∣parate from others, whether hard or liquid, as that there is none either to aid or hinder the Communication of Motions.
• Art. 5.
• Art. 63.
• Art. 55. & 43. of the second Part, and else∣where.
• General Rules of the Commui∣cation of Motions.
• †

  See M. des Cartes's Rules in the second Part of his Prin∣ciples.