Generation of a natural thing is defined as the production of a thing from the presupposed subject.²⁷ Generation is the opposite of creation. Metaphysically speaking, the thing which (ens quod) happens by generation, or is produced, or is generated, is only the substantial composit.²⁸ The substantial form, properly speaking, is not produced, nor becomes, nor is generated, but is only that by which (id quo) the composit arises, or is generated, or is produced. For the generative act, or the act eductive and unitive of form, does not terminate in the form but only in the composit from material and form.

The "solid scientific foundation" which would be required to sustain the evolutionary origin of the body of man would require, if there is no certitude, at least probability in the mind of an unprejudiced and impartial person to be able to make a judgment with serenity of mind.²⁹

The "special intervention of God" signifies here that God made the first living thing or the first organic living thing from material already existing prior to life, which material had been created by God. In other words, God produced the substantial form (the soul) of the first living organism, dependent on some pre-existing material created by God, through eductive action if the concern is with living things distinct from man, dependent on the merely passive potency of the material, and in no way dependent on the active and exigitive potency of the material. In man, God creates the human soul immediately and directly.

Negatively, "the special intervention of God" is not any of the following.³⁰ It is not miraculous, which is the operation of God above nature, against nature or besides the laws of nature, where nature is already constituted in its naturally existing being; but in the origin of the human body is considered the production or constitution "from" this nature. It is not creation, which is production from nothing of self or subject, because the living body is not produced from nothing. It is not the general concurrence of God, by which God as the Prime Cause concurs with all the effects of secondary causes, because such intervention by God is general, not special.