CHAPTER V.

EXPOSITION OF THE SYSTEMS IN GENERATION.

Plato[BL] not only explains the generation of man, animals, plants, and elements, but even that of heaven and the gods, by reflected representations and images extracted from the Divine Creator, which, by an harmonic motion, are ranged according to the properties of numbers in the most perfect order. The universe, according to him, is a copy of the Deity: time, space, motion, and matter, are images of his attributes; and secondary and particular causes are results of numerical and harmonical qualities of those representations. The world is the most perfect being, and to have a complete perfection it was necessary that it contained every other animal, every possible representation, and every imaginable form, of the creative faculty. The essence of all generation consists in the unity and harmony of the number Three, or of the triangle, viz. that _which_ generates, that _in which_ generation is performed, and that _which is_ engendered. The succession of individuals in the species is only a fugitive image of the immutable eternity of this triangular harmony, the universal prototype of every existence and every generation; for this reason two individuals are required to produce a third, and it is this which constitutes the essential order of father, mother, and child.

[BL] See the Timæus.

This philosopher is a painter only of ideas; disengaged from matter he elevates into the regions of abstraction, and, losing sight of sensible objects, perceives and contemplates the intellectual alone. One cause, one end, and one sole mode, form the whole of his perceptions. God is the cause, perfection the end, and harmonic representations the modes. What can be a more sublime idea! This plan of philosophy is replete with simplicity, and the views truly noble! but how void and destitute for speculation? We are not purely spiritual beings, nor have we the power to give a real existence to our ideas. Confined to matter, our rather dependent on what causes our sensations, the real substance can never be produced by the abstracted. I answer Plato in his own language, "The Creator realizes every thing he conceives; his perceptions engender existence: the created being, on the contrary, conceives nothing by retrenching them but from reality, and the production of his ideas do not amount to any thing."

Let us then content ourselves with a more humble and more material philosophy; and by keeping within the sphere Nature has allotted us, let us examine the rash steps and the rapid flight of those who attempt to soar beyond it. All this Pythagorean philosophy, which is purely intellectual, turns entirely on two principles, one of which is false and the other precarious: those are, the real power of abstraction, and the actual existence of final causes. To take numbers for real beings; to say that unity is a general individual, which not only represents every individual, but even communicates existence to them; to pretend that unity has the actual power to engender another unity nearly similar to itself, and constituting two individuals, two sides of a triangle, which can have no bound or perfection without a third side, or by a third individual, which they necessarily engender. To regard numbers, geometrical lines, and metaphysical abstractions, as efficient and real physical causes, on which the formation of the elements, the generation of animals and plants, and all the phenomena of Nature depend, seems to me to be the most absurd abuse of reason, and the greatest obstacle that can be put against the advancement of our knowledge. Besides, what can be more false than such suppositions? Admitting, with Plato and Malebranche, that matter does not exist, that external objects are only ideal images of the creative faculty, and that we perceive every thing in the Deity, must it be concluded from thence that our ideas should be of the same order as those of the Creator, or that they can produce existences? Are not we dependent on our sensations? Whether the objects that cause them are real or not; whether this cause of our sensations exists outwardly or inwardly; whether it be the Creator or matter we perceive, what does it signify to us? Are we less certain of being always affected in the same manner by the same causes? Have not our sensations an invariable order of existence, and a necessary relation between them and the objects? This, therefore, is what must constitute the principles of our philosophy; and what has no relation with it is vain, useless, and false in the application. Can a triangular harmony form the substance of the elements? Is fire, as Plato affirms, an acute triangle, and light and heat properties of this triangle? Air and water, are they rectangular and equilateral triangles? Is the form of the terrestrial element a square, because, being the least perfect of all the four elements, it recedes as much as possible from a triangle without losing its essence? Do the male and female embrace only to complete the triangle of generation? These platonic ideas have two very different aspects. In speculation they seem to flow from noble and sublime principles, but in application nothing but false and puerile consequences can be drawn from them.

Is it difficult to discover that our ideas proceed only from our senses? that the things we look on as real and existing are those of which our senses have always rendered us the same testimony? that those which we conceive to have certain existence are those which ever present themselves in the same order? that consequently our ideas, very far from being the causes of things, are only effects, and so far from resembling particular things, become less similar to the objects as they are more general; that at length our mental abstractions are only negative beings, which do not exist even intellectually but by the retrenchment which we make of sensible qualities to real beings.

From hence is it not plain that abstractions can never become principles, neither of existence nor real knowledge? on the contrary, our knowledge can only proceed from the results of properly comparing our sensations. These results are what is termed _experience_, the sole source of all real science. The adoption of every other principle is an abuse, and every edifice built on abstracted ideas is a temple founded on error.

Error bears a much more extended signification in philosophy than in morality: in morals a thing may be false, only because it is misrepresented. Metaphysical falsehood consists not in misrepresentation alone, but in crediting that which has no existence, and even in not being of any mode whatever. It is in this kind of error, of the first order, that the Platonists, the Sceptics, and the Egotists have fallen into, their false suppositions have obscured the natural light of truth, clouded reason, and retarded the advancement of philosophy.

The second principle made use of by Plato, and by most of the speculative philosophers, is a final cause. Nevertheless, to reduce this principle to its just value, a single moment of reflection is only requisite. To say there is light because we have eyes, and sounds because we have ears, or to say that we have ears and eyes because there is light and sound, is it not exactly the same thing? shall we ever discover any thing by this mode of explanation? Is it not evident that final causes are only arbitrary relations and moral abstractions, which should impose on us still less than metaphysical abstractions, because their origin is less noble and a more false supposition; and although Leibnitz has endeavoured to raise this principle to the highest degree by the name of _sufficient reason_, and Plato has represented it by the most flattering portrait, under the title of _perfection_, yet it cannot prevent our seeing it as trifling and precarious. Are we better acquainted with the effects of Nature, from being told that nothing is made without a reason, or that all is made in view of perfection? What is this sufficient reason? what is this perfection? are they not moral beings created by intellects purely human? are they not arbitrary relations which we have generalized? on what are they founded? on moral affinities which, far from producing any physical or real existence, only alter the reality and confound the objects of our sensations, perceptions and knowledge, with those of our sentiments, our passions and our wills.

I could adduce many arguments on this subject, but I do not pretend to make a treatise on philosophy, and shall return to physics, from which the ideas of Plato on universal generation made me digress. Aristotle, who was as great a philosopher as Plato and a much better physician, instead of losing himself in the region of hypotheses, relied, on the contrary, on collected facts, and speaks in a more intelligible language.

Matter, which is only a capacity of receiving forms, takes in generation a form like that of the individual which furnishes it; and with respect to the generation of animals that have sexes, he thinks that the male alone furnishes the prolific principle, and that the female affords nothing that can be looked upon as such.[BM] For though he says elsewhere, speaking of animals in general, that the female emits a seminal fluid within herself, yet he does not regard that as a prolific principle: nevertheless, according to him, the menstrual blood serves for the formation, growth, and nutriment of the foetus, but the efficient principles exist only in the seminal fluid of the male, which does not act like matter, but as the cause. Averrhois, Avicenna, and other philosophers, who followed the sentiments of Aristotle, have sought for reasons to prove that females have no prolific fluid; they urge, that as females have a menstrual fluid that was necessary and sufficient for generation, it does not appear natural to suppose they possess any other; particularly because it begins to appear, like the seminal fluid in the males, at the age of puberty; besides, continue they, if females have really a seminal and prolific fluid, why do they not produce without the approach of the male, since they contain the prolific principle as well as the matter necessary for the nutriment and growth of the embryo? This last reason seems to be the only one which merits any attention. The menstrual blood seems to be necessary for the support, nutriment, and growth of the foetus, but it can have no part in the first formation, which is made by the mixture of two fluids alike prolific. Females therefore may have, as well as the males, a prolific fluid for the formation of the embryo, besides the menstrual blood for its nutriment and expansion; and certainly a female being possessed of a prolific fluid, extracted from all parts of her body, as well as the necessary means of nourishment and expansion, it is no impossible imagination that she would produce females without any communication with the male. It must be allowed, that this metaphysical reasoning which the Aristotelians adopt to prove that females have no prolific fluid, may become the most considerable objection that can be made against all systems of generation, and particularly against our explanation.

[BM] See Aristotle, de gen. lib. i. cap. 20 and lib. xi. cap. 4.

Let us suppose, it may be said, as you have attempted to prove, that the superfluous organic molecules are sent back into the testicles and seminal vessels of the male, why, by the power of your supposed attracting forces, do they not form small organized beings, perfectly resembling the male? and for the same reason similar beings in the female? If you answer, that there is an appearance that the liquor of the male contains only males, and that of the female only females, but that all these perish for want of the necessary means for expansion, and that there are only those formed by the mixture of both which can expand and come into the world; may we not be asked why this mode of generation, which is the most complicated, difficult, and least abundant, is that which Nature prefers in so striking a manner, that almost all animals multiply by this mode of communication of the male with the female?

I shall content myself at present with answering, that the fact is such as we have represented it; the objection becomes a fact question; to which, as we have observed, there is no other solution to be given than that of the fact itself. It may be insisted, it is the most complicated mode of production; yet this mode, which appears the most complicated to us, is certainly the most simple for nature, because, as we have remarked, what happens the most often, however difficult it may appear to our ideas, must in reality be the most simple; which does not prevent us from conceiving it to be complex, as we judge of it according to that knowledge which our senses and reflections can give us thereon.

The assertion of the Aristotelians, that females have no prolific fluid, must fall to the ground, if we pay attention to the resemblance of children to their mothers, of mules to the female that produces them, of mongrels and mulattos, all of which resemble more the mother than the father. If, besides these, we consider the organs of females are, like those of the males, formed so as to prepare and receive the seminal fluid, we shall be readily persuaded that such a fluid must exist, whether it resides in the spermatic vessels, the testicles, or in the matrix: or whether it issues, when provoked, by the passages of de Graaf, situated at the neck, and near the external orifice of the urethra.

But it is right here to examine the ideas of Aristotle more generally on the subject of generation, because this great philosopher has written the most on the subject, and treated it the most generally. He distinguishes animals into three classes; first, those which have blood, and, excepting some few, multiply by copulation; the second, those which have no blood, but, being at the same time both male and female, produce of themselves, and without copulation; and thirdly, those bred by putrefaction, which do not owe their origin to parents of any kind. I shall first remark, that this division must not be admitted of; for though in fact all kinds of animals which have blood are composed of males and females, it is not equally true, that animals who have no blood are for the most part male and female in one; for we are only acquainted with the snail and worm on earth which are in this state; nor can we ascertain whether all shell-fish, and other animals which have no blood, be hermaphrodites. With respect to those animals which he says proceed from putrefaction, as he has not enumerated them, many exceptions occur; for most of the kinds which the ancients thought engendered by putrefaction have been discovered by the moderns to be the produce of eggs.

After this he makes a second division of animals; those which have the faculty of moving themselves progressively, as walking, flying, swimming, and those which have no such faculty. All animals which can move, and have blood, have sexes; but those which, like oysters, are adherent, or who scarcely move at all, have no sex, and are, in this respect like plants, distinguished only, as he says, into males and females by difference of size. It is not yet ascertained whether shell-fish have sexes or not; there are in the oyster-kind fruitful individuals, and others which are not so; those which are fruitful are distinguished by a delicate border which surrounds the body of the oyster, and they are called males.[BN]

[BN] See the observation of M. Deslandes, in the Tracte de la raine, Paris, 1747.

But to proceed, the male, according to Aristotle, includes the principle of generative, motion, and the female contains the material parts of generation. The organs which serve for this purpose are different in the different kind of animals; the principal are the testicles in the males, and the matrix in the females. Quadrupeds, birds, and cetaceous animals, have testicles; fish and serpents are deprived of them; but they have both proper conduits to receive and prepare the seed. These essential parts are always double, both in the male and female, and serve in males to stop the motion of the blood, which forms the seed. This he proves by the example of birds, whose testicles swell in the season of their amours, and diminish so greatly when this season is over that they are scarcely perceptible.

All quadrupeds, as horses, oxen, &c. which are clothed with hair, and cetaceous fishes, as dolphins and whales, are viviparous; but cartilaginous animals, and vipers, are not truly viviparous, because they produce an egg within themselves before the live animal appears. Oviparous animals are of two kinds, those which produce perfect eggs, as birds, lizards, turtles, &c. and those which produce imperfect eggs, as fishes, whose eggs augment and come to perfection after they have been laid in the water by the female; and in all kinds of oviparous animals, excepting birds, the females are generally larger than the males, as fishes, lizards, &c.

After having mentioned these general varieties in animals, Aristotle begins with examining the opinion of the ancient philosophers, that the seed, as well of the male as of the female, proceeded from all parts of the body; he declares against this opinion, because, he says, although children often resemble their fathers and mothers, they also sometimes resemble their grandfathers; and, besides, they resemble their parents by the voice, hair, nails, carriage, and manner of walking. Now the seed, he continues, cannot proceed from the hair, voice, nails, or any external quality, like that of walking; therefore children do not resemble their parents because the seed comes from every part of the body, but for some other reason. It appears to me unnecessary here to point out the weakness of these arguments; I shall only observe that it appears to me this great man expressly sought after methods to separate himself from the sentiments of those philosophers who preceded him; and I am persuaded, that whoever reads his treatise on generation with attention, will discover that a strong design of giving a new system, different from that of the ancients, obliged him always to give the preference to the least probable reasons, and to elude, as much as he could, the force of proofs, when they were contrary to his general principles of philosophy.

According to Aristotle the seminal liquor is secreted from the blood; and the menstrua, in females, is a similar secretion, and the only one which serves for the purpose of generation. Females, he says, have no other prolific liquor; there is, therefore, no mixture of that of the male with that of the female. He pretends to prove this from some women conceiving without receiving the least pleasure, and because few women emit this liquor externally during copulation; that in general those who are brown, and have a masculine appearance, do not emit at all, yet engender equally with those who are more fair in complexion and feminine in appearance, and whose emissions are considerable. Thus he concludes woman furnishes nothing but the menstrual. This blood is the matter of generation; and the seminal fluid of the male does not contribute as matter but as form; it is the efficient cause, the principle of motion; it is to generation what the sculptor is to a block of marble: the liquor of the male is the sculptor, the menstrual blood the marble, and the foetus the image.

The menstrual blood receives from the male seed a kind of soul, which gives life and motion. This soul is neither material nor immaterial, because it can neither act upon matter nor enter in generation as matter, the menstrual blood being all that is necessary for that purpose. It is, says our philosopher, a spirit, whose substance is like that of the starry region. The heart is the first work of this soul; it contains in itself the principle of its own growth; and it has the power to arrange the other members. The menstrual blood contains every other principle of all the parts of the foetus: the soul, or spirit, of the male seed, makes the heart begin to act, and that communicates the power of bringing the other viscera to action; and thus, successively, is every part of the animal unfolded and brought into motion. All this appeared very clear to our philosopher; there only remained to him one doubt, which was, whether the heart was realized before the blood; and in fact he had reason for this doubt; for, although he had adopted the opinion of the heart existing first, Harvey has since pretended, by reasons of the same kind as those used by Aristotle, that it was not the heart but the blood which is first realized.

This is the system that great philosopher has given us of generation, and I shall leave it to the opinion of the reader whether that of the ancients, which he rejects, can be more obscure or more absurd than his; nevertheless, his system has been followed by most of the learned. Harvey has not only adopted the ideas of Aristotle, but has added new ones of the same kind. As this system of generation is of the same kind as the rest of Aristotle's philosophy, where form and matter are the grand principles; where the vegetative and sensitive are the active beings in Nature; and where final causes are real objects; I am not surprised that it has been received by scholastic authors; but it is astonishing that so able a physician and observer of Nature as Harvey was, should be carried away with the stream, while every physician followed the opinion of Hippocrates and Galen; which we shall explain in order. We must not, however, imbibe a disadvantageous idea of Aristotle from the above exposition of his System of Generation. It would be like judging of Descartes by his Treatise on Man. The explanations which these two philosophers give of the formation of the foetus should not be considered as complete systems on the subject of generation; they are rather general consequences drawn from their philosophical principles.

_END OF THE SECOND VOLUME._

Transcriber Note

Non-standard capitalization has been retained. Hyphenation was standardized. All obvious typographical corrections made. The following list of changes were also made:

Page Change ==== =================================================== 47 Added missing endquote first paragraph 50 Harleim was changed to Haarlem 58 "which" was added: " ... causes [which] agitates and disturbs it ..." 155 Added missing endquote first paragraph 225 Added missing endquote first paragraph 246 Timaeo was changed to Timæus.