Anatomical exercitations concerning the generation of living creatures to which are added particular discourses of births and of conceptions, &c. / by William Harvey ...

THE PREFACE.

SInce many have requested, and some have importuned mee; it will not, I hope, be unwelcome, (candid Reader) if what I have observed concerning the Generation of A∣nimals, out of Anatomical dissections (for I have found the whole matter to be much different, from that which is deli∣vered, either by Philosophers or Physi∣tians) I expose in these Exercitations, in favour, and for the use of the Lovers of Truth.

All Physitians, following Galen, teach, that out of the Seed of Male and Female mingled in Coition, according to the pre∣dominant power of this, or that, the Child resembles either this, or that Parent, and is also either Male or Female. And some∣times they pronounce the Males Seed to be the Efficient cause, and the Females the Materiall; and sometimes again the clean contrary.

But Aristotle (Natures most diligent searcher) affirms that the Male and Female are the principles of Generation, and that she contributes the matter, and he the form; and that forthwith after Coition, there is formed in the Womb out of the Men∣struous bloud, the Vital principle, and first particle of the future Foetus, (namely, the Heart, in Creatures that have bloud.)

But that these are false, and rash asser∣tions, will soon appear; and will like clouds instantly vanish, (when the light of Anatomical dissection breaks forth) nor will they require any elaborate confutati∣on, when the Reader, instructed by his own eyes, shall discover the contrary by ocular inspection; and shall also under∣stand, how unsafe, and degenerate a thing it is, to be tutored by other mens com∣mentaries, without making tryal of the things themselves: especially, since Natures Book is so open, and legible.

I have therefore exhibited to publick view, what in these my Exercitations, I intend to deliver concerning the Generati∣on of Animals; not onely that posterity may thence discern the certain and appa∣rent truth; but also, and that cheifly too, that (by revealing the Method I use in searching into things) I might propose to

studious men, a new, and (if I mistake not) a surer path to the attainment of knowledge.

For although it be a more new and dif∣ficult way, to find out the nature of things, by the things themselves; then by read∣ing of Books, to take our knowledge up∣on trust from the opinions of Philoso∣phers: yet must it needs be confes∣sed, that the former is much more open, and lesse frandulent, especially in the Se∣crets relating to Natural Philosophy.

Nor is there any reason, why any man should be deterred by the trouble of it; if he will but so much as consider with himselfe, that even life it selfe is continu∣ed to him, by the never Wearied Agitati∣on of the Heart. Nor truly would this journy present so much of solitude and desart to us; did not most men by the custome (or fault rather) of the age wee live in, yeilding themselves up to slug∣gishnesse, desire rather to erre with the many, then with the expense of their paines and coine, endeavour to be wise with the few: when notwithstanding the Ancient Philosophers (whose industry also even we extol) went a quite contrary way to work; and by indefatigable toile sear∣ching after several experiments, have set

up a clear light to direct our studies. So that, whatever notable and approved thing we have in Philosophy, it all is de∣rived unto us by the paines and industry of ancient Greece. Yet when we content our selves with their discoveries, and calmly believe (which is meer sleepiness) that there is now no more place for new inventions, the spritely edge of our owne wit languisheth, and we extinguish the lamp which they lighted to our hands. And certainly he alone wil grant, that the whole truth was ingrossed by the Anci∣ents, (who is ignorant of the many noble discoveries, to pass by other Arts) lately found out in the business of Anatomy. And this was cheifly done either by such, who wholly intent upon some one thing, did casually descry some other: or (which is more commendable) by those, who fol∣lowing Natures conduct with their own eyes, have at length through a perplexed, but yet a most faithful tract, attained to the highest pitch of Truth. And in such an undertaking it is pleasant, not to be tyred onely, but even to faint away; where the Irkesomness of Discovering is abundant∣ly recompensed by the discovery it selfe. We use, being covetous of Novelty, to wander far into unknown lands, that our

own eies may witness, what our ears have received at second hand: where yet for the most part

—minuit praesentia famam. Our sight decries report.

Let us then blush, in this so ample, and so wonderful field of nature, (where per∣formance still exceeds what is promised) to credit other mens traditions only, and thence coine uncertain problemes, to spin out thorney and captious questions. Na∣ture her selfe must be our adviser; the path she chalks must be our walk: for so while we confer with our own eies, and take our rise from meaner things to high∣er, we shall be at length received into her Closet-secrets.

Of the Manner and Order of attaining knowledge.

THough there be one onely roade to Science, namely, that by which we proceed from things more known, to things known less; and from that which is more manifest, to that which is more obscure; and though Universals are chiefly known to us (for Science is begot by reasoning

from Universals to Particulars) yet that ve∣ry comprehension of Universals in the Un∣derstanding, springs from the perception of Singulars in our sense. So that both A∣ristotles * 1.1 assertions are true, as well that in his Physicks; There is a way naturally lay∣ed from those things which are more known and cleare to us, to those things which are more intelligible and cleare by nature. For the same things are not both known to us, and simply so too: wherefore we of necessity must thus proceed; to wit, from those things which are by nature indeed more obscure, but yet are more clearer to us; to those things which are more cleare and intelligible by nature. But those things are first perspieuous and manifest to us, which are most confused. Therefore wee must goe from Vniversals to Singulars: for the Whole is more known by sense: now an Vniversal is a certain Whole. As that in his Analyticks. Singulars are more known by * 1.2 us, and doe first exist according to sense: for nothing is in the understanding, which was not before in the sense. And although that Ratiocination is naturally first and more known, which is made by Syllogisme; yet that is more conspicuous to us, which is made by Induction: and therefore we define Singu∣lars with more ease, then Universals: for there lyes more Aequivocation in Vniversals. Where∣fore

wee must pass from Singulars to Ge∣nerals.

That which we have now delivered, hangs very well together, though at first it seem to clash: because Generals are first collected from Singulars by sense, and so farre onely are more known to us, as an U∣niversal is a certain whole and indistinct thing; and that Whole is more known to us according to sense. For though in all knowledge, we begin from Sense, because, (as the Philosopher said before) Sensible particulars are most known to Sense; yet Sensation it selfe is an Universal thing. For (if you minde it well) though (while we perceive) that which is in the outward organ of sense be a Singular, as suppose, a yellow colour, in the sight: yet that which is thence abstracted by the internall sense, and is judged and apprehended by it, is an Universal. Hence it comes to pass, that several persons, do at the same instant, abstract divers species, and fashion severall notions, even of one and the same Object. As it is evident in Poets, and Pain∣ters: who, though at the same time, and in the same place, all circumstances being alike, they behold one and the same Object, yet each of them, be they never so many, express and describe it a several way, ac∣cording

to the several Ideas which they have drawn in their Phansie. So that a Painter being to draw any one mans pi∣cture, though he take a thousand several draughts, will make them all distinct fa∣ces; and them too not onely differing from each other, but from the Archetype it selfe: yet with so small distinction, that if you look upon each of them apart, you will think hee still brings the same piece hee brought before: and yet set them all together and compare them, and you will plainely discover a difference. Now the reason of all this is, that in Ui∣sion, or the act of Seeing, each particular by it selfe was clear and distinct: which very particular, the Object being remo∣ved, (as suppose you should shut your eies,) abstracted in the Phansie, or laid up in the Memory, is presented obscure, and confused: nor is it any longer apprehend∣ed as a particular, but as some General and Universal thing.

This subtilty Seneca doth elegantly ex∣press, * 1.3 according to Plato's opinion. An Idea, saith he, is an eternal Exemplar of Natural things. I will explain this definiti∣on, that you may conceive it the better. Sup∣pose I intend to draw your picture, you your self are the Exemplar of that picture, from

whom my minde takes a representation, which she indeavoureth to pattern in her work. So then your face, which is my director, & which I labour to represent, is the Idea. And a li∣tle after, he saith. In my discourse even now I made use of a picture-drawer, to illu∣strate what I was speaking of. He, when he would paint Virgil, his eye is upon Virgil himself: Virgils face is his Idea, and the Exemplar of his future designe: now that which the Artist takes from this Idea, and worketh off, is the Picture. If you demand the difference between these two, it is this: the one is the Pattern, the other is the copy ta∣ken by the Pattern, and layed upon the work: He imitates the one, and makes the other. A Statue hath a face, but that face is but the Idos, or representation: But the Exemplar which the Statuary copies out, hath a face, and that face is the Idaea. Doe you desire a far∣ther explication? take it thus. The Idos is that which you see in the piece: the Idea is quite without the piece, and not onely with∣out it, but also had a being before the piece was at all. For those things that have been formerly observed, and either by use, or custome have taken deep root in the minde of the Artificer, doe consti∣tute art it selfe, and the Operative Habit: for Art it self is nothing but the reason of the

work, implanted in the Artists minde. And the same way by which we gaine an Art, by the very same we attain any kinde of science or knowledge whatever: for as Art is a habit whose object is something to be done; so Science is a habit, whose object is something to be known: and as the for∣mer proceedeth from the imitation of Ex∣emplars; so this latter, from the knowledge of things naturall. The Sourse of both is from sense and experience; since it is im∣possible that Art should rightly be pur∣chased by the one, or Science by the other, without a direction from Ideas. Yet in both Art & Science too, that thing which in sensible objects wee perceive, differs from the perception it self, which is kept in the memory, or imagination. That, is the exemplar, the Idea, the forme inform∣ing: this, the Representation, the Idos, the abstracted Species. That, is a natural thing, a real entity; this, a resemblance, or simili∣tude, and an ens rationis. That, is imploy∣ed about some particular thing, and is it selfe a singular, and an individual; this, is a kinde of universal and common thing. That, is in every Artist and Philosopher, a sensible thing, clear, and perfect; this be∣longs to the mind, and is obscure. For what wee discover by sense, is much more sure

and manifest, then what we discover by the Intellect: because the latter springs from the former, and is illustrated by it. To conclude, Sensible Objects are of them∣selves, and before Intelligible; but Intelli∣gible are after them, and arise from them: nor can we attain to them at all, without their help.

Wherefore it is, that our judgement er∣reth about phantasmes and apparitions comprised in our minds, unless sense give a right verdict, established upon frequent observations, and infallible experiments. For in every Science, be it what it will, a diligent observation is requisite, and Sense it self must be frequently consulted. We must not (I say) rely upon other mens experience, but on our owne; without which, no man is a proper disciple of a∣ny part of natural knowledge; nor a competent judge of what I shall deliver concerning Generation; for without expe∣rimentall skill in Anatomy, he will no better apprehend it, then a man born blind can judge of the nature and difference of colours; or one born deaf, of Sounds. There∣fore (discreet Reader) trust nothing I say, about the Generation of Animals; I appeale to none but thine eyes. For since every perfect Science builds upon those

Principles, which it finds out by Sense: we must have a special care, that by customa∣ry dissections, we be sure those Principles are safely grounded. If we do otherwise, we may get a tumid and floating opinion: but never a solid and infallible knowledge: As it happeneth to those, who see forraign countries only in Mapps, and the bowels of men falsly described in Anatomical tables. And hence it comes about, that in this rank age, we have many Sophisters, and Book∣wrights; but few wise men, and Philosophers.

And thus much I thought fit to pre∣mise as a Tast, that you may understand, by what helps I my self was assisted, and upon what consideration I was induced to communicate these my Observations, and Experiments: and that you treading the same path, may be able not onely to be in equitable Umpire between Aristotle, & Galen, but also forsaking al subtleties; and probable conjectures, and viewing Nature in her own glass, may search out many o∣ther things yet unrevealed, and perhaps more precious.

Of the former matters, according to Aristotle.

NO kind of knowledge is innate to us, according to Aristotle: For neither

Opinion, nor Art, nor Understanding, nor Speech, nor Reason it self, are in us by na∣ture, and from our birth; but all these are of the linage of those things, which hap∣pen to us from without, according to nature As also all those qualities and habits which are esteemed to be spontaneous, & placed within our own power; such are Virtues and Vices, for which we receive nei∣ther commendation, and reward, or dis∣grace, & punishment. The knowledg ther∣fore of any thing whatsoever must be ou•• proper purchase. But which are the first principles of this knowledge, is not the scope of this discourse.

Yet I suppose it will not be amiss, t•• premise here, Whence, and How we com•• to know, that we may attain to a mo•••• perfect understanding of the Generation Animals, and also take away any scruple which any man might raise about Aristotle opinion. For he affirms, all doctrine, an•• * 1.4 Dianoetical discipline to be framed out of pre∣cedent knowledge: Whence it seems to in∣sue, that there is either no first knowledge or else that that first knowledge is bo•••• with us; which is dissonant to what is sai•• before.

This doubt is hereafter cleared by A∣ristotle * 1.5 himself; where he teacheth th••

manner how knowledge is acquired. For having taught, that all certain knowledge is gained by Syllogism, and Demonstration; and that all demonstrative Syllogismes, are built upon some first, true, and necessary principles; he at last inquires, how princi∣ples become known, and what is that notify∣ing habit; as also, whether habits are begot∣ten, since they were not in us before; or else, whether they lurked conceal'd, in case they were in us? We have not, saith he, those habits; for it happens that they are hid from those who acquire more exquisite knowledge by de∣monstration. But if we receive them, when we had them not before, how should we make it known, and how should we learn out of a non-preceding knowledge? It is plaine there∣fore that we have them not, and that they are not in us, and we not know of them; and that they cannot be begotten in men that have yet no habit at all. Wherefore it necessarily follows, that we have some power to attain them, and yet not such a one as is more excel∣lent, and exquisite then they. Now this seems to be a common thing to all creatures living: to have a connate power of Judging, which is called Sense.

Now since they have Sense, some of them retain in them the things they perceive by sense, and some not. They who retain not,

have either no knowledge at all, or else no knowledge of what they do not retain, beyond the bare sensation it self. Others do retaine in their Soul something of what they perceive. And since there are many such, they are thus differenced; that in some there doth result a certain discourse from the memory of things retained, and in some not. By Sense there∣fore memory is made, as we say; and out of a frequent remembrance of the same thing, is experience made: (for many numerical Re∣membrances, are one Experience) but out of Experience, or an Universal resting in the soul (namely out of one, which is distinct from the many particulars, and is one and the same in all of them) is raised a Principle of Art, and Science: of Art, if it relate to Generation; (that is, to doing, or effecting;) of Science, if it appertain to that which is, (that is, to the knowledge of an Entity simply;) so that the habits we speak of, are neither naturally in us, neither are they made out of other habits more known, but they proceed from Sense.

By which words of Aristotle, it evident∣ly appears, by what Order the knowledge of any Art, or Science is attained: Name∣ly, by Sense there remains an impression of the thing perceived: by that impression is made a remembrance of it, and from mul∣tiplied memory, proceeds Experience: from

Experience, Universal Reason, Definitions, Ma∣ximes, or common Axioms, which are the most certain Principles of knowledge. As for example, The same thing, under the same capacity cannot possibly be, and not bee. Every Affirmation, or Negation, is either true or false; and so forth.

Wherefore, as we said before, no per∣fect knowledge, which may be called ours, is in us; but such as is in some sort derived to us from Experience, and Sense; or is at least examined, and approved by them, and strongly grounded upon some knowledge pre-existent in us. For without memory, there can be no experience, which is nothing else but a multiplied me∣mory: neither can memory bee, without a remaining impression of the sensative ob∣ject, and the object cannot remaine, where it never was.

The great Dictator of Philosophy hath * 1.6 another passage to this purpose. All men naturally desire knowledge. And this is evidenced, by the love of our Senses: amongst which we prefer the sight; because this chief∣ly conveyeth knowledge to us, and distingui∣sheth best of things.

Now naurally Animals are sensative: but some of them remember not what they perceive by sense, and some do. And for this cause

some are prudent, some are more capable of discipline then others that remember not. Pru∣dent, without being taught; as all those that have not the sense of hearing, as Bees, and all such other kinds of creatures; But all crea∣tures may be taught which have both memory, and hearing too.

Therefore other creatures have phansies, and memories, but have no title to experience. But Men have Arts, and Ratiocination. And to them experience comes by remembrance: for many recordations of the same thing, make one Experience. Wherefore experience seems much of kin to Art, and Science. For by expe∣rience men gain both Art and Science. For Experience begets Art (as Polus rightly notes) but Inexperience, Chance.

By which he clearly shews, that no man * 1.7 can be truely called prudent, or knowing, who doth not by his own experience (at∣tained by manifold remembrance, fre∣quent sensation, and diligent obser∣vation) know things to be so. For without that, we think onely, or beleive: and such a knowledge as that, is to be re∣puted other mens, rather then our owne. Wherefore fond and erroneous is that Method of seeking truth, in use in our times: while most men diligently inquire, not what the truth is, but what other men

say it is: and inferring Universal conclu∣sions from particular premisses, & thence shaping to themselves irrational deducti∣ons, they transmit to us things like truth, for truth it self.

Hence it is, that Sophisters and halfe-knowing men, polling other mens inven∣tions, saucily impose them upon us for their own; (shifting onely the phrase and order, and adding some impertinencies of their own) and render Philosophy (which ought to be clear and perspicu∣ous) obscure, intricate, and confused. For whosoever they be that read authors, and do not, by the aid of their own Senses, ab∣stract true representations of the things themselves (comprehended in the authors expressions) they do not resent true Ideas, but deceitful Idols, & Phantasms; by which means they frame to themselves certaine shadows and Chimaera's, and all their theory and contemplation (which they count Science) represents nothing but waking mens dreams, and sick mens phrensies.

Give me leave therefore to whisper this to thee (friendly Reader) that thou be sure to weigh all that I deliver in these Exerci∣tations, touching the Generation of living Creatures, in the steady scale of experi∣ment; and give no longer credit to it,

then thou perceivest it to be securely bot∣tomed, by the faithful testimony of thy own eyes. This very thing did Aristotle per∣swade us to; who when he had discour∣sed much of Bees, added at last: That the Generation of Bees is after this manner, ap∣pears * 1.8 by reason, and by those things which are seen to come to pass after the maner of Bees. Yet have we not a sufficient discovery of what may fall out. Therefore when the discovery shall be compleated, then is Sense more to be trusted to, then Reason. For so far onely is Reason to be relied upon, as those things which are demon∣strated, agree with those things which are perceived by sense.

Of the Method to be observed in the knowledge of Generation.

SInce therefore in the Generation of A∣nimals (as in all other things of which we covet to know any thing) every inqui∣sition is to be derived from its Causes, and chiefly from the Material and Efficient; it seems fit to me, looking back on perfect animals (namely by what degrees they are begun, and compleated) to retreat, as it were, from the end to the beginning: that so at last when there is no place for farther

retreat, we may be confident we have ar∣rived at the principles themselves: and then it will appear, out of what first mat∣ter, by what efficient, and what procession the plastick power hath its original; and then also what progress Nature makes in this work. For both the first, and re∣moter matter, appears the clearer (being stripped naked as it were) by Negation; and whatsoever is first made in Generation, that is, as it were, the material cause of that which succeedeth. So, for example, A Man, was first a Boy (because from a Boy he grew up to be a Man;) before he was a Boy, he was an Infant; and before an In∣fant, an Embryo.

Now we must search farther, what hee was in his Mothers Womb, before he was this Embryo, or Foetus; whether three bubbles? or some rude and indigested lump? or a conception, or coagulation of mixed seed? or whether any thing else? according to the opinion of writers.

In the same manner, before a Hen or Cock came to perfection, (and that is cal∣led a perfect Animal, that can beget its like) there was a Chicken; before that Chic∣ken, there is seen in the egge an Embryo, or Foetus; and before that Embryo, Hieronymus Fabricius Aquapendens hath descried the

rudiments of the Head, Eyes, and Spine of the Back. But where he affirms, that the Bones are made before the Muscles, Heart, Liver, Lungs, and all the Viscera; and that all the inward parts ought to exist before the outward; he relieth upon probability, ra∣ther then experience; and laying aside the verdict of sense, which is grounded upon dissections; he flies to petty reasonings borrowed from mechanicks: which is ve∣ry unbeseeming so famous an Anato∣mist. For he ought to have told us what daily changes his own eyes had discover∣ed in the egge, ere ever the Foetus came to perfection. Especially seeing he professed∣ly wrote the History of the Generation of the Chicken out of the Egge; and hath described in pictures what progress is made from day to day. It was, I say, befitting so much diligence, to have acquainted us from the allegation of his own sight, what things in the egge are made first, what last, and what happen together: and not to have confined himself to the example of build∣ing of Ships, and Houses, to render a clou∣dy conjecture and perswasion only, of the order, and manner of forming the parts.

We therefore (according to the Me∣thod proposed) will explaine, first in an Egge, and afterwards in other Conceptions

of several creatures, what is constituted first, and what last, in a most miraculous order, & with a most inimitable prudence and wisdome, by the great God of nature; and at length we will discover, what we have found out, concerning the first mat∣ter out of which, and the first efficient by which, the foetus is made, as also of the order & Oeconomy of Generation: that thence we may attain to some infallible know∣ledge of each faculty of the formative and vegetative Soul, by the effects of it; and of the nature of the Soul it selfe, by the parts, or organs of the body, and their functi∣ons.

Now this indeed we could not perform in all kind of Animals; because some of them cannot be gotten; and others again are so exceeding small, that our eyes can hardly discern them.

Let it suffice therefore that we have done it in some creatures, which are more known to us; to whose platform, the first originals of all other creatures may be re∣duced. We have made choice therefore of such, as might render the credit of our experiments lesse questionable, namely larger, and perfecter creatures, and such as are within our own power. For in the larger creatures, all things are more con∣spicuous;

in the perfecter, more distinct; and in those that are in our own power, & conversant amongst us, more obvious: so that we have liberty (at pleasure) by searching into them, to rescue our obser∣vations from wavering hesitation. And of this sort, in the race of Oviparous crea∣tures, are Hens, Geese, Pigeons, Ducks Eishes, Shel-fish of both kinds (as Lob∣sters, Oysters, &c.) Fishes that have no shells at all, Frogs, Serpents: also Infects, as Bees, Waspes, Butterflies, Silkworms. And of Viviparous, Sheep, Goats, Dogs, Cats, all Cattel that divide the Hoofe; and in chief, the perfectest of all creatures, Man himself.

Having thorough insight & knowledge of these things, we may then contemplate the abstruse nature of the Vegetative Soul; and discern in all creatures what ever, the manner, order, and causes of their Generation: because all other creatures agree either generically, or specifically with the fore-ci∣ted, or at the least with some of them; and are procreated after the same manner of generation, or else in a manner proporti∣oned to it. For Nature being divine, and perfect, is always consonant to her self in the same things. And as her works do ei∣ther agree or differ (namely in kind, speci∣es,

or some analogy) so her operation (that is to say, generation or Fabrick) is the same or different in them. Whoever entereth this new, and unfrequented path, and in∣quires for truth in the vast volume of Na∣ture, by Anatomical dissections, and expe∣riments, he meets with such a croud of ob∣servations, and those too in such exotick shapes, that to unfould to others the my∣steries himself hath discovered, will bee more toyl, then the finding of them out: for many things occurr which have yet no name; such is the plenty of things, and the dearth of words. So that if a man should cloath them in Metaphors, and express his new inventions by old words, and such as are in use: the Reader could no more un∣derstand them, then canting: and would never be able to comprehend the business, since he never saw it.

And then again to mint up new and fi∣ctitious terms, would rather cast a mist, then enlighten. For so he must needs ex∣press things unknown, by that which is lesse known: and the Reader would be more afflicted to unriddle the words, then to understand the matter. And therefore Aristotle by unexperimented persons is thought obscure: And this perhaps was the reason, why Fabricius ab Aquapendente

chose rather to describe the Fabrick of the Chicken in the Egge by tables then words.

Therefore be not offended, Courteous Reader, if in setting out the History of an Egge, and in the description of the Genera∣tion of the Chicken, I make use of a new me∣thod, and sometimes of unusual terms; nor think me hereby more desirous of vain∣glory, then of advantaging others by true experiments, and such as are groun∣ded in Natures self. To take off that pre∣judice, know, I tread but the steps of other men who have lighted me the way, and (so farre as is fit) I make use of their noti∣ons. But in chief, of all the Ancients, I follow Aristotle; and of the later Writers, Hieronymus Fabricius ab Aquapendente, Him as my General, and This as my Guide. For as they which finde out new Plantations, and new Shores, call them by names of their own coyning, which Posterity afterwards accepts and receives; so those that finde out new Secrets, have good title to their compellation. And here, me thinks, I hear Galen advising; If we consent in the things; contend not about the words:

Notes

• * 1.1

  L. 1. c. 2. 3.
• * 1.2

  Post. 2.
• * 1.3

  Epist. 58.
• * 1.4

  Analyt. post. l. 1. c. 1.
• * 1.5

  Ib. l. 2. cap. ult.
• * 1.6

  Metaph. l. 1. c. 1.
• * 1.7

  Apud. Plat. in Gorgiâ.
• * 1.8

  De gen. an. l. 3. c. 1.