The Works of William Harvey M.D. / Translated from the Latin with a life of the author

by William Harvey

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. Aristotle[393] 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,[394] “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 audits,’ on hearsay wonders; and elsewhere he says,[395] “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 a long 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?[396] “Every fourth birth,” says Pliny,[397] “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,[398] 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.