Decameron physiologicum, or, Ten dialogues of natural philosophy by Thomas Hobbes ... ; to which is added The proportion of a straight line to half the arc of a quadrant, by the same author.

CAP. I. Of the Original of Natural Philoso∣phy. (Book 1)

A.

I Have heard exceeding highly commended a kinde of thing which I do not well understand, though it be much talkt of, by such as have not otherwise much to do, by the name of Philosophy. And the same a∣gain by others as much despised and derided. So that I cannot tell whether it be good or ill, nor what to make of it, though I see many other men that thrive by it.

B.

I doubt not, but what so many do so highly praise must be very admirable, and what is derided and scorn'd by many, foolish and ridiculous. The honour and scorn fal∣leth finally not upon Philosophy, but upon the Professors. Philosophy is The knowledge of Natural Causes. And there is no Know∣ledge but of Truth. And to know the true

Causes of things, was never in contempt, but in admiration. Scorn can never fasten upon Truth. But the difference is all in the Wri∣ters and Teachers. Whereof some have nei∣ther studied, nor care for it, otherwise than as a Trade to maintain themselves or gain Pre∣ferment; and some for Fashion, and to make themselves fit for ingenious Company: and their study hath not been meditation, but ac∣quiescence in the Authority of those Authors whom they have heard commended. And some (but few) there be, that have studied it for Cu∣riosity, and the delight which commonly men have in the acquisition of Science, and in the mastery of difficult and subtil Doctrines. Of this last sort I count Aristotle, and a few others of the Ancients, and some few Moderns: and to these it is that properly belong the Praises which are given to Philosophy.

A.

If I have a minde to study (for exam∣ple Natural Philosophy) must I then needs read Aristotle, or some of those that now are in request?

B.

There's no necessity of it. But if in your own meditation you light upon a difficulty, I think 'tis no loss of time, to enquire what o∣ther men say of it, but to rely onely upon Reason. For though there be some few Ef∣fects of Nature (especially concerning the Heavens) whereof the Philosophers of old time have assigned very rational Causes, such

as any man may acquiesce in, as of Eclipses of the Sun and Moon by long observation, and by the Calculation of their visible Motions; yet what is that to the numberless and quoti∣dian Phaenomena of Nature? Who is there amongst them or their Successors, that has sa∣tisfied you with the Causes of Gravity, Heat, Cold, Light, Sense, Colour, Noise, Rain, Snow, Frost, Winds, Tides of the Sea, and a thousand other things which a few mens lives are too short to go through, and which you and other curious Spirits admire (as quotidian as they are) and fain would know the Causes of them, but shall not finde them in the Books of Na∣turalists; and when you ask what are the Causes of any of them, of a Philosopher now, he will put you off with mere words; which words, examined to the bottom, signifie not a jot more than I cannot tell, or Because it is: Such as are Intrinsecal quality, Occult quality, Sympathy, Antipathy, Antiperistasis, and the like. Which pass well enough with those that care not much for such wisdom, though wise enough in their own ways; but will not pass with you that ask not simply what's the Cause, but in what manner it comes about that such Effects are produced.

A.

That's Cozening. What need had they of that? When began they thus to play the Charletants?

B.

Need had they none. But know you

not that men from their very birth, and natu∣rally, scramble for every thing they covet, and would have all the world, if they could, to fear and obey them? If by fortune or indu∣stry one light upon a Secret in Nature, and thereby obtain the credit of an extraordina∣ry Knowing man, should he not make use of it to his own benefit? There is scarce one of a thousand but would live upon the charges of the people as far as he dares. What poor Geometrician is there, but takes pride to be thought a Conjurer? what Mountebank would not make a living out of a false opinion that he were a great Physician? And when ma∣ny of them are once engaged in the mainte∣nance of an Errour, they will joyn together for the saving of their Authority to decry the Truth.

A.

I pray, tell me, if you can, how and where the study of Philosophy first began.

B.

If we may give Credit to old Histories, the first that studyed any of the Natural Sci∣ences were the Astronomers of Aethiopia. My Author is Diodorus Siculus, accounted a very faithful Writer, who begins his History as high as is possible, and tells us that in Aethiopia were the first Astronomers; and that for their Predictions of Eclipses, and other Conjuncti∣ons and Aspects of the Planets, they obtained of their King not onely Towns and Fields to a third part of the whole Land, but were also

in such veneration with the People, that they were thought to have discourse with their Gods, which were the Stars; and made their Kings thereby to stand in awe of them, that they durst not either eat or drink but what and when they prescribed; no nor live, if they said the Gods commanded them to die. And thus they continued in subjection to their false Prophets, till by one of their Kings, called Ergamenes, (about the time of the Ptolemies) they were put to the Sword. But long be∣fore the time of Ergamenes, the Race of these Astrologers (for they had no Disciples but their own Children) was so numerous, that a∣bundance of them (whether sent for or no I cannot tell) transplanted themselves into E∣gypt, and there also had their Cities and Lands allowed them, and were in request not onely for Astronomy and Astrologie, but also for Geometry. And Egypt was then as it were an University to all the world, and thither went the curious Greeks, as Pythagoras, Plato, Thales, and others, to fetch Philosophy into Greece. But long before that time, abundance of them went into Assyria, and had their Towns and Lands assigned them also there; and were by the Hebrews called Chaldies.

A.

Why so?

B.

I cannot tell; but I finde in Martinius Lexicon they were called Chasdim, and Ches∣dim, and (as he saith) from one Chesed the

son of Nachor; but I finde no such man as Chesed amongst the issue of Noah in the Scri∣pture. Nor do I finde that there was any certain Country called Chaldaea; though a Town where any of them inhabited were cal∣led A Town of the Chaldies. Martinius saith further, that the same word Chasdim did signi∣fie also Demons.

A.

By this reckoning I should conjecture they were called Chusdim, as being a Race of Ethiopians. For the Land of Chus is Aethiopia; and so the name degenerated first into Chul∣dim, and then into Chaldim; so that they were such another kinde of people as we call Gypsies; saving that they were admired and feared for their Knavery, and the Gypsies counted Rogues.

B.

Nay pray, except Claudius Ptolomaeus, Author of that great Work of Astronomy, the Almegest.

A.

I grant he was excellent both in Astro∣nomy and Geometry, and to be commended for his Almegest; but then for his Judiciar A∣strologie annexed to it, he is again a Gypsie. But the Greeks that travelled (you say) into Egypt, what Philosophy did they carry home?

B.

The Mathematiques and Astronomy. But for that sublunary Physiques, which is com∣monly called Natural Philosophy, I have not read of any Nation that studied it earlier than the Greeks, from whom it proceeded to the

Romans. Yet both Greeks and Romans were more addicted to Moral than to Natural Phi∣losophy; in which kinde we have their Wri∣tings, but loosly and incoherently, written up∣on no other Principles than their own Passi∣ons and Presumptions, without any respect to the Laws of Common-wealth, which are the ground and measure of all true Morality. So that their Books tend rather to teach men to censure than to obey the Laws. Which has been a great hinderance to the Peace of the Western world ever since. But they that se∣riously applied themselves to Natural Philoso∣phy were but few, as Plato and Aristotle, whose Works we have; and Epicurus, whose Doctrine we have in Lucretius. The Writings of Phi∣lolaus and many other curious Students being by fire or negligence now lost: though the Doctrine of Philolaus concerning the Motion of the Earth have been revived by Copernicus, and explained and confirmed by Galileo now of late.

A.

But methinks the Natural Philosophy of Plato and Aristotle, and the rest, should have been cultivated and made to flourish by their Disciples.

B.

Whom do you mean, the Successors of Plato, Epicurus, Aristotle, and the other first Philosophers? It may be some of them may have been learned and worthy men. But not long after, and down to the time of our Sa∣viour

and his Apostles, they were for the most part a sort of needy, ignorant, impudent chea∣ting fellows, who by the profession of the Do∣ctrine of those first Philosophers, got their li∣ving. For at that time, the name of Philo∣sophy was so much in fashion and honour a∣mongst great persons, that every rich man had a Philosopher of one Sect or another to be a Schoolmaster to his Children. And these were they that faining Christianity, with their disputing and readiness of talking got them∣selves into Christian Commons, and brought so many Heresies into the Primitive Church, every one retaining still a tang of what they had been us'd to teach.

A.

But those Heresies were all condemned in the first Council of Nice.

B.

Yes. But the Arrian Heresie for a long time flourished no less than the Roman, and was upheld by divers Emperours, and never fully extinguished as long as there were Van∣dals in Christendom. Besides, there arose daily other Sects, opposing their Philosophy to the Doctrine of the Councils concerning the Divinity of our Saviour; as, how many Persons he was, how many Natures he had. And thus it continued till the time of Charle∣main, when he and Pope Leo the third divi∣ded the Power of the Empire into Temporal and Spiritual.

A.

A very unequal division.

B.

Why? Which of them think you had the greater share?

A.

No doubt, the Emperour: For he onely had the Sword.

B.

When the Swords are in the hands of men, whether had you rather command the Men or the Swords?

A.

I understand you. For he that hath the hands of the Men, has also the use both of their Swords and strength.

B.

The Empire thus divided into Spiritual and Temporal, the freedom of Philosophy was to the power Spiritual very dangerous. And for that cause it behoved the Pope to get Schools set up not onely for Divinity, but al∣so for other Sciences, especially for Natural Philosophy. Which when by the power of the Emperour he had effected, out of the mix∣ture of Aristotle's Metaphysicks with the Scri∣pture, there arose a new Science called School-Divinity; which has been the principal Lear∣ning of these Western parts from the time of Charlemain till of very late.

A.

But I finde not in any of the Writings of the School-men in what manner, from the causes they assigne, the Effect is naturally and necessarily produced.

B.

You must not wonder at that. For you enquire not so much, when you see a change of any thing, what may be said to be the cause of it, as how the same is generated; which

generation is the entire progress of Nature from the efficient cause to the Effect produced. Which is always a hard Question, and for the most part impossible for a man to answer to. For the alterations of the things we perceive by our five Senses are made by the motion of Bodies (for the most part) either for distance, smalness, or transparence, invisible.

A.

But what need had they then to assigne any cause at all, seeing they could not shew the Effect was to follow from it?

B.

The Schools (as I said) were erected by the Pope and Emperour, but directed by the Pope onely, to answer and confute the Heresies of the Philosophers. Would you have them then betray their Profession and Authority, that is to say, their Livelihood, by confessing their ignorance? Or rather uphold the same, by putting for causes, strange and unintelligible words; which might serve well enough not onely to satisfie the people whom they relied on, but also to trouble the Philosophers them∣selves to finde a fault in.

A.

Seeing you say that Alteration is wrought by the Motion of Bodies, pray tell me first what I am to understand by the word Body.

B.

It is a hard Question, though most men think they can easily answer it, as that it is whatsoever they can see, feel, or take notice of by their Senses. But if you will know indeed what is body, we must enquire first what there

is that is not Body. You have seen (I suppose) the Effects of Glasses, how they multiply and magnifie the Object of our sight; as when a Glass of a certain Figure will make a Counter or a Shilling seem twenty, though you be well assured there is but one. And if you set a mark upon it, you will finde the mark upon them all. The Counter is certainly one of those things we call Bodies: Are not the o∣thers so too?

A.

No, without doubt. For looking through a Glass cannot make them really more than they are.

B.

What then be they but fancies, so many fancies of one and the same thing in several places?

A.

'Tis manifest they are so many Idols, mere Nothings.

B.

When you have look'd upon a Star or Candle with both your eyes, but one of them a little turn'd awry with your finger, has not there appeared two Stars, or two Candles? And though you call it a deception of the sight, you cannot deny but there were two I∣mages of the Object.

A.

'Tis true, and observed by all men. And the same I say of our faces seen in Looking∣glasses, and of all Dreams, and of all Appari∣tions of dead mens Ghosts; and wonder, since 'tis so manifest, I never thought upon't before, for it is a very happy encounter, and such as

being by every body well understood, would utterly destroy both Idolatry and Superstition, and defeat abundance of Knaves that cheat and trouble the world with their devices.

B.

But you must not hence conclude that whosoever tells his Dream, or sometimes takes his direction from it, is therefore an Idolater, or Superstitious, or a Cheater. For God doth often admonish men by Dreams of what they ought to do; yet men must be wary in this case that they trust not Dreams with the con∣duct of their lives further than by the Laws of their Country is allow'd: For you know what God says, Deut. 13. If a Prophet or a Dreamer of Dreams give thee a signe or a wonder, and the signe come to pass, yet if he did thee serve other Gods, let him be put to death. Here by serving other Gods (since they had chosen God for their King) we are to understand revolting from their King, or disobeying of his Laws. Otherwise I see no Idolatry nor Superstition in following a Dream, as many of the Patriarches (in the Old Testament) and of the Saints (in the New Testament) did.

A.

Yes: Their own Dreams. But when another man shall dream, or say that he has dream'd, and require me to follow that, he must pardon me if I ask him by what Autho∣rity, especially if he look I should pay him for it.

B.

But if commanded by the Laws you live

under, you ought to follow it. But when there proceed from one Sound divers Echoes, what are those Echoes? And when with fin∣gers cross'd you touch a small Bullet, and think it two; and when the same Herb or Flower smells well to one and ill to another, and the same at several times, well and ill to your self, and the like of Tastes, what are those Echoes, Feelings, Odours, and Tastes?

A.

'Tis manifest they are all but Fancies. But certainly when the Sun seems to my eye no bigger than a Dish, there is behinde it some∣where somewhat else (I suppose a real Sun) which creates those fancies, by working (one way or other) upon my eyes, and other Or∣gans of my Senses, to cause that diversity of Fancy.

B.

You say right; and that is it I mean by the word Body, which briefly I define to be any thing that hath a Being in it self, without the help of Sense.

A.

Aristotle (I think) meaneth by Body, Substance, or Subjectum, wherein Colour, Sound, and other Fancies are (as he says) in∣herent. For the word Essence has no affinity with Substance. And Seneca says, he under∣stands it not. And no wonder: for Essence is no part of the Language of mankinde, but a word devised by Philosophers out of the Co∣pulation of two names, as if a man having two Hounds could make a third (if 'twere need) of ther•• Couples.

B.

'Tis just fo. For having said in themselves (for example) A Tree is a Plant, and concei∣ving well enough what is the signification of those Names, knew not what to make of the word Is that couples those Names; nor daring to call it a Body, they called it by a new name, (derived from the word est) Essentia, and Sub∣stantia, deceived by the Idiome of their own Language. For in many other Tongues, and namely in the Hebrew, there is no such Copu∣lative. They thought the Names of things sufficiently connected, when they are placed in their natural consequence; and were there∣fore never troubled with Essences, nor other Fallacy from the Copulative Est.