# The Works of William Harvey/Anatomical Exercises on the Generation of Animals/On Conception

ON CONCEPTION.
ON CONCEPTION.
Fabricius has indeed recounted many wonderful things on the subject of parturition; for my own part, I think there is more to admire and marvel at in conception. It is a matter, in truth, full of obscurity; yet will I venture to put forth a few things— rather though as questions proposed for solution—that I may not appear to subvert other men's opinions only, without bringing forward anything of my own. Yet what I shall state I wish not to be taken as if I thought it a voice from an oracle, or desired to gain the assent of others by violence; I claim, however, that liberty which I willingly yield to others, the permission, viz. in subjects of difficulty to put forward as true such things as appear to be probable until proved to be manifestly false.
It is to the uterus that the business of conception is chiefly intrusted: without this structure and its functions conception would be looked for in vain. But since it is certain that the semen of the male does not so much as reach the cavity of the uterus, much less continue long there, and that it carries with it a fecundating power by a kind of contagious property, (not because it is then and there in actual contact, or operates, but because it previously has been in contact); the woman, after contact with the spermatic fluid in coitu, seems to receive influence, and to become fecundated without the co-operation of any sensible corporeal agent, in the same way as iron touched by the magnet is endowed with its powers and can attract other iron to itself. When this virtue is once received the woman exercises a plastic power of generation, and produces a being after her own image; not otherwise than the plant, which we see endowed with the forces of both sexes.
​Yet it is a matter of wonder where this faculty abides after intercourse is completed, and before the formation of the ovum or "conception." To what is this active power of the male committed? is it to the uterus solely, or to the whole woman? or is it to the uterus primarily and to the woman secondarily? or, lastly, does the woman conceive in the womb, as we see by the eye and think by the brain?
For although the woman conceiving after intercourse sometimes produces no fœtus, yet we know that phenomena occur which clearly indicate that conception has really taken place, although without result. Over-fed bitches, which admit the dog without fecundation following, are nevertheless observed to be sluggish about the time they should have whelped, and to bark as they do when their time is at hand, also to steal away the whelps from another bitch, to tend and lick them, and also to fight fiercely for them. Others have milk or colostrum, as it is called, in their teats, and are, moreover, subject to the diseases of those which have actually whelped; the same thing is seen in hens which cluck at certain times, although they have no eggs on which to sit. Some birds also, as pigeons, if they have admitted the male, although they lay no eggs at all, or only barren ones, are found equally sedulous in building their nests. The virtue which proceeds from the male in coitu has such prodigious power of fecundation, that the whole woman, both in mind and body, undergoes a change. And although it is the uterus made ready for this, on which the first influences are impressed, and from which virtue and strength are diffused throughout the body, the question still remains, how it is that the power thus communicated remains attached to the uterus? is it to the whole uterus or only to a part of it? nothing is to be found within it after coitus, for the semen in a short time either falls out or evaporates, and the blood, its circle completed, returns from the uterus by the vessels.
Again, what is this preparation or maturity of the uterus which eagerly demands the fecundating seed? whence does it proceed? Certain it is, unless the uterus be ready for coition every attempt at fecundation is vain; nay, in some animals, at no other time is the male admitted. It happens occasionally, I allow, that this maturity arrives earlier in some from the ​solicitations of the male animal; it is itself, however, a purely natural result, just as is the ripening of the fruit in trees. What these changes are I will now recount, as I have found them by observation.
The uterus first appears more thick and fleshy; then its inner surface, the future residence, that is, of the "conception," becomes softer, and resembles in smoothness and delicacy the ventricles of the brain; this I have already described in the deer and other cloven-footed tribes. But in the dog, cat, and other multiparous and digitated animals, the horns of the uterus—clearly corresponding to the round tubes of the woman [Fallopian tubes], the appendices of the intestines in birds, or the ureters in man—exhibit little protuberances at certain intervals, which swell up and become extremely soft; these, after intercourse, appear to open themselves, (as I have observed in deer;) from them the first white fluid transudes into the uterus, and out of this the "conception," or ovum, is formed. In this way the uterus, by means of the male, (like fruit by the summer's heat,) is brought to the highest pitch of maturity, and becomes impregnated.
But since there are no manifest signs of conception before the uterus begins to relax, and the white fluid or slender threads (like the spider's web) constituting the "primordium" of the future "conception," or ovum, shows itself; and since the substance of the uterus, when ready to conceive, is very like the structure of the brain, why should we not suppose that the function of both is similar, and that there is excited by coitus within the uterus a something identical with, or at least analogous to, an "imagination" (phantasma) or a "desire" (appetitus) in the brain, whence comes the generation or procreation of the ovum? For the functions of both are termed "conceptions," and both, although the primary sources of every action throughout the body, are immaterial, the one of natural or organic, the other of animal actions; the one (viz. the uterus) the first cause and beginning of every action which conduces to the generation of the animal, the other (viz. the brain) of every action done for its preservation. And just as a "desire" arises from a conception of the brain, and this conception springs from some external object of desire, so also from the male, as being the more perfect animal, and, as it were, the most ​natural object of desire, does the natural (organic) conception arise in the uterus, even as the animal conception does in the brain.
From this desire, or conception, it results that the female produces an offspring like the father. For just as we, from the conception of the "form" or "idea" in the brain, fashion in our works a form resembling it, so, in like manner, the "idea," or "form," of the father existing in the uterus generates an offspring like himself with the help of the formative faculty, impressing, however, on its work its own immaterial "form." In the same way art, which in the brain is the εἶδος or "form" of the future work, produces, when in operation, its like, and begets it out of "matter." So too the painter, by means of conception, pictures to himself a face, and by imitating this internal conception of the brain carries it out into act; so also the builder constructs his house according to previous conception. The same thing takes place in every other action and artificial production. Thus, what education effects in the brain, viz. art, with its analogue does the coitus of the male endow the uterus, viz. the plastic art; hence many similar or dissimilar foetuses are produced at the same coitus. For if the productions and first conceptions of art (the mere imitations of nature) are in this way formed in the brain, how much more probable is it that copies (exemplaria) of animal generation and conception should in like manner be produced in the uterus?
And since Nature, all of whose works are wonderful and divine, has devised an organ of this kind, viz. the brain, by the virtue and sensitive faculty of which the conceptions of the rational soul exist, such as the desires and the arts, the first principles and causes of so many and such various works, of which man, by means of the impulsive faculty of the brain, is by imitation the author; why should we not suppose that the same Nature, who in the uterus has constructed an organ no less wonderful, and adapted it by means of a similar structure to perform all that appertains to conception, has destined it for a similar or at least an analogous function, and intended an organ altogether similar for a similar use? For as the skilful artificer accomplishes his works by ingeniously adapting his instruments to each, so that from the substance and shape of these ​instruments it is easy to judge of their use and application, with no less certainty than we have been taught by Aristotle to recognize the nature of animals from the structure and arrangement of their bodily organs; and as physiognomy instructs us to judge of a man's disposition and character from the shape of his face and features, what should prevent us from supposing that where the same structure exists there is the same function implanted?
But it is so unfairly ordered that, when customary and familiar matters come to be debated, this very familiarity lessens their importance and our wonder; whilst things of much less moment, because they are novel and rare, appear to us far greater objects of marvel. Whoever has pondered with himself how the brain of the artist, or rather the artist by means of his brain, pictures to the life things which are not present to him, but which he has once seen; also in what manner birds immured in cages recall to mind the spring, and chant exactly the songs they had learned the preceding summer, although meanwhile they had never practised them; again, and this is more strange, how the bird artistically builds its nest, the copy of which it had never seen, and this not from memory or habit, but by means of an imaginative faculty (phantasia), and how the spider weaves its web, without either copy or brain, solely by the help of this imaginative power; whosoever, I say, ponders these things, will not, I think, regard it as absurd or monstrous, that the woman should be impregnated by the conception of a general immaterial "idea," and become the artificer of generation.
I know well that some censorious persons will laugh at this,—men who believe nothing true but what they think so themselves. Yet this that I do is the practice of philosophers, who, when they cannot clearly comprehend how a thing really is brought to pass, devise some mode for it in accordance with the other works of nature, and as near as possible to what is true. And indeed all those opinions which we now regard as of the greatest weight, were at the beginning mere figments and imaginations, until confirmed by experiments addressed to the senses, and made credible by a knowledge of their positive causes. Aris​totle says "that philosophers are in some sort lovers of fables, seeing that fable is made up of marvels." And indeed men were first led to cultivate philosophy from wondering at what they saw. For my own part, then, when I see nothing left in the uterus after intercourse to which I can ascribe the principle of generation, any more than there is in the brain anything discoverable after sensation and experience, which are the prime sources of art, and when I find the structure of both alike, I have devised this fable. Let learned and ingenious men consider of it, let the supercilious reject it, and those who are peevish and scoffing laugh if they please.
Since, then, nothing can be apprehended by the senses in the uterus after coition, and since it is necessary that there be something to render the female fruitful, and as this is probably not material, it remains for us to take refuge in the notion of a mere conception and of "species without matter" (species sine materiâ), and imagine that the same thing happens here as every one allows takes place in the brain, unless indeed there be some one "whom the gods have moulded of better clay," and made fit to discover some other efficient cause besides any of those enumerated.
Some philosophers of our time have returned to the old opinion about atoms, and so imagine that this generative contagion, as indeed all others, proceeds from the subtile emanations of the semen of the male, which rise like odorous particles, and gain an entrance into the uterus at the period of intercourse. Others invoke to their aid incorporeal spirits, such as demiurgi, angels, and demons. Others regard it as a process of fermentation. Others devise other theories. I pray, therefore, a place for this conjecture of mine until something certain is established in the matter.
Many observations have been made by me which would easily overthrow the opinions I have mentioned, so easy is it to say what a thing is not rather than what it is; this is not, however, the place to introduce them, although elsewhere it is my intention to do so. On the present occasion I shall only observe, if that which is called by the common name of "contagion," as arising from the contact of the spermatic fluid in ​intercourse, and which remains in the woman (without the actual presence of the semen) as the efficient of the future offspring—if, I say, this contagion (whether it be atoms, odorous particles, fermentation, or anything else) is not of the nature of any corporeal substance, it follows of necessity that it is incorporeal. And if on further inquiry it should appear that it is neither spirit nor demon, nor soul, nor any part of the soul, nor anything having a soul, as I believe can be proved by various arguments and experiments, what remains, since I am unable myself to conjecture anything besides, nor has any one imagined aught else even in his dreams, but to confess myself at a stand-still? "For whoever," says Aristotle, "doubts and wonders, confesses his ignorance; therefore if to escape the imputation of ignorance, ingenious men have turned to philosophy, it is clear they follow their pursuit for the sake of knowledge, and not from any other motive."
It must not, then, be imputed to me for blame, if, eager for knowledge, and approaching untrodden ground, I have presented aught which at first sight may appear made up or fabulous. For as everything is not to be received at once with an unthinking credulity, so that which has been long and painfully considered must not be straightway rejected, even although it fail to catch the eye of the quick-sighted. Aristotle himself wrote a book, 'De Mirabilibus auditis,' on hearsay wonders; and elsewhere he says, "We must not only thank those in whose opinions we acquiesce, but those also who have said aught (to the purpose) although superficially. For these bring in something to the common stock, in this, that they exercise and train our habits. For if Timotheus had not existed, we should have lost much music. Yet if Phrynis had not been we should have had no Timotheus. So is it with those who have laid down any truth. For we have received some opinions from certain philosophers, yet were there others to whom these owed their existence."
Influenced, then, by the example and authority of so great a man, and not to appear resolute only to subvert the doctrines of others, I have preferred proposing a fanciful opinion rather than none at all, playing in this the part of Phrynis to ​Timotheus, my object being to shake off the sloth of the age we live in, to rouse the intellects of the studious, and, rather than that the diligent investigator of nature should accuse me of indolence, to bid him laugh at my ill-formed and crude notions.
In truth, there is no proposition more magnificent to investigate or more useful to ascertain than this: How are all things formed by an "univocal" agent? How does the like ever generate the like? And this not only in productions of art (for so house builds house, face designs face, and image forms image), but also in things relating to the mind, for mind begets mind, opinion is the source of opinion. Democritus with his atoms, and Eudoxus with his chief good which he placed in pleasure, impregnated Epicurus; the four elements of Empedocles, Aristotle; the doctrines of the ancient Thebans, Pythagoras and Plato; geometry, Euclid. By this same law the son is born like his parents, and virtues which ennoble and vices which degrade a race are sometimes passed on to descendants through along series of years. Some diseases propagate their kind, as lepra, gout, syphilis, and others. But why do I speak of diseases, when the moles, warts, and cicatrices of the progenitor are sometimes repeated in the descendant after many generations? "Every fourth birth," says Pliny, "the mark of the origin of the Dacian family is repeated on the arm." Why may not the thoughts, opinions, and manners now prevalent, many years hence return again, after an intermediate period of neglect? For the divine mind of the Eternal Creator, which is impressed on all things, creates the image of itself in human conceptions.
Having, therefore, overcome some difficulties relating to the subject, I feel a greater desire to enter into it a little more closely, and this with two objects in view—first, that what I have hitherto treated cursorily may seem to carry with it a greater weight of probability; and secondly, to stir up the intellects of the studious to search more deeply into so obscure a subject.
To illustrate the matter, let A stand for the fecundated egg (the "matter" that is of the future chick), which is alterable or ​convertible into the chick, and is in fact the chicken in posse. Let B be that which fecundates the egg, and thus distinguishes it from an unfruitful egg, i. e. the "efficient cause" of the chick, or that which puts the egg in motion, and converts it into a chick. And let C be the chick, or "final cause," for the sake of which both the egg and that which fecundates the egg exist, the actual chick, namely, or "reason" why the chick is.
Now we take for granted, as demonstrated by Aristotle, that every prime mover is "combined with" that which is moved by it. And these things are more particularly said by him to be "together" which are generated or produced at the same moment of time: thus that which moves and that which is moved are actually together, and where one is there the other is also; for it is evident that when the effect is present the cause must be so too.
Whenever, then, A (i. e. the fecundated egg) is actually in being, B (i. e. the internal moving and "efficient" or fecundating cause) is also actually in being. But when B is actually in being, C also (i. e. the immaterial "form" of the chick) must, at least in some sort, be existing too. For B is the internal efficient cause of the chick, that, namely, which alters A (the egg) into C (the "reason" why the chick is). Since, then, everything which moves coexists with that which is moved by it, and every cause with its effect, it follows that C coexists with B; for the "final cause," both in nature and art, is primary to all other causes, since it moves, and is not itself moved; but the "efficient" moves, because it is impelled by the "final cause." There inheres, in some way or other, in every "efficient cause" a ratio finis (a final cause), and by this the efficient, co-operating with Providence, is moved.
The authority of Aristotle is clearly on my side: "That," he says, "appears to hold the chief place among natural causes which we signify under this expression, 'cujus gratiâ'—for whose sake. For this is the 'reason;' but the 'reason' is the chief thing, as well in artificial as in natural subjects. For when a physician explains what health is, either by definition or description, or a workman a house, he is accustomed to give ​the reasons and causes of what he does, and adds why he does it; although that cause, 'cujus gratiâ,' and the reason 'for the sake of the good and fair,' are joined rather to the works of nature than to those of art."
"The end," he elsewhere says, "is this 'cujus gratiâ' (for whose sake), as health is the thing for the sake of which we walk. For why does a man walk? We answer, for the sake of his health; and when we have thus said, we think we have given a 'cause;' and whatever else is further interposed, by means of another agent, is done for the sake of this end, as dieting, or purging, or drugs, or instruments, are all for the sake of health; for all these are for the sake of the end." Again, "It is our business always to seek the primary cause of everything, For instance, a man builds a house because he is a builder, but he is a builder by reason of the art of building; this then (the art) is a prior cause; and so in all things." Hence it is that he asserts "that the cause which first moves, and in which the 'reason' and 'form' lie, is greater and more divine than the 'material cause.'"
In all natural generation, therefore, both the "matter" out of which and the "efficient cause" by which (namely, A, the thing which is moved, and B, the thing moving) are alike for the sake of the animal begotten or to be begotten; for that which moves and is not itself moved, viz. C, is in (inest) both. For both those (viz. A and B) are at the same time capable of motion, and are moreover moved, viz. the thing fecundating, B, (which both moves and is moved) and the thing fecundated, A, the "matter," viz. or ovum, which is moved and changed only. Wherefore if no moveable thing is actually moved, unless the thing which moves is present, so neither will "matter" be moved, nor the "efficient" effect anything, unless the first moving cause be in some way present; and this is the "form" or "species" which is without matter, and is the prime cause. "For the efficient and generating," according to Aristotle, "in so far as they are so, belong to that which is effected and generated." The following syllogism, therefore, may be framed out of these first and necessary predicates:
​Whenever B is actually in existence, C also is actually in existence (i. e. moving in some way).
Whenever A is actually in existence, B is also in actual existence.
Therefore whenever A is in actual existence, C is also in actual existence.
Natural and artificial generation take place after the same manner. Both are instituted for the sake of something further, and by a kind of providence both direct themselves to a proposed end;—both too are first moved by some "form" conceived without matter, and are the products of this conception. The brain is the organ of one kind of conception (for in the soul, the organ of which is the brain, art, without the intervention of matter, is the "reason" or first cause of the work), the uterus or ovum of the other.
The "conception," therefore, of the uterus or the ovum resembles, at least in some sort, the conception of the brain itself, and in a similar way does the "end" inhere in both. For the "species" or "form" of the chick is in the uterus or ovum without the intervention of matter, just as the "reason" of his work is in the artist, e.g. the "reason" of the house in the brain of the builder.
But since the phrase "to be in" is perhaps equivocal, and things are said to be coexistent in various senses, I affirm, further, and say, that the "species" and immaterial "form" of the future chick are, in some sort, the cause of the impregnation or fecundation of the uterus, because after intercourse no corporeal substance can be found within that organ.
But how this immaterial cause, this first principle, exists alike in the uterus and brain, or how the conceptions of the brain and uterus, answering to art and nature, resemble or differ from each other, and in what way the thing which fecundates (viz. the internal efficient cause whereby the animal is generated) exists alike in the male and his semen and in the woman and her uterus—in the egg also, the mixed work of both sexes—and wherein their differences consist, I shall subsequently attempt to explain when I treat generally of the generation of animals (as well of those creatures which are produced by metamor​phosis, viz. insects, as of spontaneously generated beings, in whose ova or "primordia," as in all other seeds, the "species" or immaterial "form" plainly dwells, the moving principle, as it were, of those things which are to be generated), and when I speak of the soul and its affections, and how art, memory, and experience are to be regarded as the conceptions of the brain alone.
* ↑ Analyt. lib. ii, cap. 35.
* ↑ Metaphys. lib. i, cap. 2.
* ↑ Metaphys. lib. i, cap. 2.
* ↑ Ibid. lib. ii, cap. 1.
* ↑ Arist. Hist. Animal. lib. vii, cap. 6; et De Gen. Anim. lib. i, cap. 17.
* ↑ Lib. vii, cap. 11.
* ↑ De Part. Anim. lib. i, cap. 1.
* ↑ Physiologia, lib. vii, cap. 3.
* ↑ Physiologia, lib. ii, tract. 3.
* ↑ De Gen. Anim. lib. ii, cap. 1.
* ↑ Ibid. cap. 4.
* ↑ Arist. de Part. Anim. lib. i, cap. 1.