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:
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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.