Whether putrefaction is a path to generation.
Further one inquires whether putrefaction is a path to generation.
1. It seems not. For putrefaction is a final corruption. But corruption is not a path to generation, since these are contraries. Therefore, etc.
2. In addition, art imitates nature to the extent that it is able. But art casts off or rejects the superfluous and creates a work of art [artificiatum] from the residue. Therefore, so too does nature, in the same way. But something made through putrefaction is superfluous and is expelled by nature. Therefore, putrefaction does not become generation.
3. In addition, the corruption that proceeds from heat is of two types, namely, combustion and putrefaction. But an animal is not generated from combustion, and therefore neither is it generated by putrefaction.
The Philosopher says the opposite.
To the first, one must reply that an animal can be generated from putrefaction. For just as the semen in the womb is digested and completed during an act of digestion by an internal power, and whatever is impure is expelled and whatever is pure that remains is converted into the matter for the fetus, so the putrefied matter in the earth's belly can be digested correctly by the heat of a celestial body, of the earth's body, or of the containing body, and what is impure can be expelled, and what is pure and remains can be in potency to the animal's form, because, just as an internal heat disposes the animal's matter for the generation of something animate, so the external heat can dispose the matter for the generation of an imperfect animal.
1. On to the arguments. To the first, one must reply that, according to the Philosopher in the first book of On Generation, "the generation of one thing is the corruption of another." Therefore, although putrefaction represents the final corruption of one thing, nevertheless it can be a pathway into the generation of another.
2. To the second argument one must reply that just as art does not form a work of art out of a separated superfluity, but out of what remains, so too does nature operate in putrefaction.
3. To the third argument one must reply that life depends on the hot and the moist, and not the hot and the dry. But in putrefaction the hot operates with the moist, whereas in combustion the hot operates with the dry. This is why combustion does not cause generation as putrefaction does.
Whether animals like this are generated by a superior power.
Further one inquires whether animals like this are generated by a superior power.
1. It seems that they are not generated by a superior power. For a cause and effect are so proportioned that the universal is proportioned to the universal and the particular to the particular. But a superior power has the nature of a universal agent, but the one generated is a particular, and therefore, etc.
2. In addition, motion impedes the generation of animals like this. An indication of this is that they are not generated in running water, whereas they are generated in standing water. Since, then, celestial bodies are in continuous motion, it seems that animals like this are not generated by the power of superior bodies.
The Philosopher says the opposite.
One must reply that two powers are required for the generation of animals like these, namely, a superior power and an inferior power. The inferior power disposes the matter for putrefaction, into which, once it has been disposed, the celestial power is introduced, operating on the matter just as sperm operates on the menses. And this is why, just as the power of the sperm disposes the menses to the form of a perfect animal, so the celestial power operates through an elemental power on matter that is disposed to the form of an imperfect animal. Therefore, just as "the human generates a human as does the sun," so it can be said that the sun and the surrounding material generate this sort of imperfect animal. The fact that an animal like this can be generated without a seed arises from its imperfection, since the more perfect an inferior thing is, the more things are required to produce it. And this is why, although an animal like this can be produced without seed by a celestial body's power and by the power of the body containing it, nevertheless a horse and an ass and a human cannot be produced solely by a universal agent without the seed of a particular animal agreeing with it in species.
1. On to the arguments. To the first, one must reply that a universal is of two kinds: one for causing and the other for disposing. Aristotle's remark must be understood to apply to the second universal and not to the first, and a celestial body is a universal agent for causing and not for disposing, and this is why it can produce a particular effect well. And this is the reason why a universal agent or celestial body acts only with a particular agent mediating it instrumentally, since all inferior things are instruments of superior ones.
2. To the second argument one must reply that the motion of the surrounding material prohibits putrefaction, and this is why water's motion thins and purifies more than it putrefies, because its own motion continually incorporates the superior power into the impure water. But this is not so for the motion of superior bodies, because their motion causes heat here below. And likewise motion continues here below because, if the first mover should happen to cease to move, then all motion here below would cease. Therefore, the motion of a superior body does not impede putrefaction, but rather arouses the heat needed for generating, although the water's motion impedes the putrefaction of the surrounded body.