From the generation of the chick, it is also manifest that, whatever may have been its principle of life or first vegetative cause, this cause itself first existed in the heart. Now, if this be the soul of the chicken, it is equally clear, that that soul must have existed in the punctum saliens and the blood; since we there discover motion and sense; for the heart moves and leaps like an animal. But if a soul exists in the punctum saliens, forming, nourishing, and augmenting the rest of the body, in the manner which we have pointed out in our history, then it, without doubt, flows from the heart, as from a fountain-head, into the whole body. Likewise, if the existence of the vital principle (anima) in the egg, or, as Aristotle supposes, if the vegetative part of the soul be the cause of its fertility, it must follow that the punctum saliens, or animate genital part, proceeds from the vital principle (anima) of the egg, (for nothing is its own author,) and that the said vital principle (anima) passes from the egg into the punctum saliens, presently into the heart, and thence into the chick.
Moreover, if the egg have a prolific virtue, and a vegetative soul, by which the chick is constructed, and if it owe them, as is allowed on all hands, to the semen of the cock; it is clear that this semen is also endowed with an active principle (anima.) For such is Aristotle’s opinion, when he expresses himself as follows: “As to whether the semen has a vital principle (anima) or not, the same reasoning must be adduced which we have employed in the consideration of other parts. For no active principle (anima) can exist, except in that thing whose vital principle it is; nor can there be any part which is not partaker of the vital principle, except it be equivocally, as the eye of a dead man. We must, therefore, allow, both that the semen has an active principle (anima) and is potential.”
Now from these premises, it follows that the male is the primary efficient in which the ratio and forma reside, which produces a seed or rather a prolific geniture, and imparts it, imbued as it is with an anima vegetativa (with which also the rest of its parts are endowed) to the female. The introduction of this geniture begets such a movement in the material of the hen, that the production of an animate egg is the result, and from thence too the first particle of the chick is animated, and afterwards the whole chick. And so, according to Aristotle, either the same soul passes, by means of some metempsychosis, from the cock into his geniture, from the geniture into the material of the female, thence into the egg, and from the egg into the chick; or else, it is raised up in each of the subsequent things by its respective antecedent; namely, in the seed of the male by the male himself, in the egg by the seed, last in the chick by the egg, as light is derived from light.
The efficient, therefore, which we look for in the egg, to explain the birth of the chick, is the vital principle (anima); and therefore, the vital principle of the egg; for, according to Aristotle, a soul does not exist except in that thing whose soul it is.
But it is manifest, that the seed of the male is not the efficient of the chick; neither as an instrument capable of forming the chick by its motion, as Aristotle would have it, nor as an animate substance transferring its vitality (anima) to the chick. For in the egg there is no semen, neither does any touch it, nor has ever done so; (“and it is impossible that that which does not touch should move, or that anything should be affected by that which does not move it,”) and therefore the vitality of the semen ought not to be said to exist in it; and although the vital principle may be the efficient in the egg, yet it would not appear to result more from the cock or his semen, than from the hen.
Nor, indeed, is it transferred by any metempsychosis or translation from the cock and his semen into the egg, and thence into the chick. For how can this translation be carried on into the eggs that are yet to exist, and to be conceived after intercourse? unless either some animate semen be in the mean time working in some part of the hen; or the vital principle only have been translated without the seed, in order to be infused into any egg which might thereafter be produced; but neither of these alternatives is true. For in no part of the hen is the semen to be found; nor is it possible that the hen after coition should be possessed of a double vital principle, to wit, her own, and that of the future eggs and chicks; since “the living principle or soul is said to be nowhere but in that thing whose soul it is,” much less can one or more vital principles lie hidden in the hen, to be afterwards subservient to the future eggs and chicks in their order, as they are produced.
We have adduced these passages out of Aristotle in order to set forth his opinion of the manner in which the seed of the cock produces the chick from the egg; and thereby throw at least some light on this difficult question. But whereas the said passages do not explain the mode in which this is accomplished, nor even solve the doubts proposed by himself, it appears that we are still sticking in the same mud, and caught in the same perplexities (concerning the efficient cause of the fœtus in the generation of animals;) indeed, so far from Aristotle’s arguments rendering this question more clear, they appear on the contrary to involve it in more and greater doubts.
Wherefore it is no wonder that the most excellent philosopher was in perplexity on this head, and that he has admitted so great a variety of efficient causes, and at one time has been compelled to resort to automatons, coagulation, art, instruments, and motions, for illustrations; at another time to an ‘anima’ in the egg, and in the seed of the male. Moreover, when he seems positively and definitively to determine what it is in each seed, whether of plants or animals, which render the same fertile, he repudiates heat and fire as improper agents; nor does he admit any faculty of a similar quality; nor can he find anything in the seed which should be fit for that office; but he is driven to acknowledge something incorporeal, and coming from foreign sources, which he supposes (like art, or the mind) to form the fœtus with intelligence and foresight, and to institute and ordain all its parts for its welfare. He takes refuge, I say, in a thing which is obscure and not recognizable by us; namely, in a spirit contained in the seed, and in a frothy body, and in the nature in that spirit, corresponding in proportion to the elements of the stars. But what that is, he has nowhere informed us.
EXERCISE THE FORTY-EIGHTH.
The opinion of Fabricius on the efficient cause of the chick is refuted.