Reply Obj. 1: This passage of Augustine is to be understood of the whole corporeal nature considered as a whole, which thus has no nature inferior to it, on which it can act; as the spiritual nature acts on the corporeal, and the uncreated nature on the created. Nevertheless one body is inferior to another, forasmuch as it is in potentiality to that which the other has in act.
From this follows the solution of the second objection. But it must be observed, when Avicebron argues thus, "There is a mover who is not moved, to wit, the first maker of all; therefore, on the other hand, there exists something moved which is purely passive," that this is to be conceded. But this latter is primary matter, which is a pure potentiality, just as God is pure act. Now a body is composed of potentiality and act; and therefore it is both active and passive.
Reply Obj. 3: Quantity does not entirely hinder the corporeal form from action, as stated above; but from being a universal agent, forasmuch as a form is individualized through being in matter subject to quantity. The proof taken from the weight of bodies is not to the purpose. First, because addition of quantity does not cause weight; as is proved (De Coelo et Mundo iv, 2). Secondly, it is false that weight retards movement; on the contrary, the heavier a thing, the greater its movement, if we consider the movement proper thereto. Thirdly, because action is not effected by local movement, as Democritus held: but by something being reduced from potentiality to act.
Reply Obj. 4: A body is not that which is most distant from God; for it participates something of a likeness to the Divine Being, forasmuch as it has a form. That which is most distant from God is primary matter; which is in no way active, since it is a pure potentiality.
Reply Obj. 5: The term of a body's action is both an accidental form and a substantial form. For the active quality, such as heat, although itself an accident, acts nevertheless by virtue of the substantial form, as its instrument: wherefore its action can terminate in a substantial form; thus natural heat, as the instrument of the soul, has an action terminating in the generation of flesh. But by its own virtue it produces an accident. Nor is it against the nature of an accident to surpass its subject in acting, but it is to surpass it in being; unless indeed one were to imagine that an accident transfers its identical self from the agent to the patient; thus Democritus explained action by an issue of atoms. _______________________
SECOND ARTICLE [I, Q. 115, Art. 2]
Whether There Are Any Seminal Virtues in Corporeal Matter?
Objection 1: It would seem that there are no seminal virtues in corporeal matter. For virtue (ratio) implies something of a spiritual order. But in corporeal matter nothing exists spiritually, but only materially, that is, according to the mode of that in which it is. Therefore there are no seminal virtues in corporeal matter.
Obj. 2: Further, Augustine (De Trin. iii, 8, 9) says that demons produce certain results by employing with a hidden movement certain seeds, which they know to exist in matter. But bodies, not virtues, can be employed with local movement. Therefore it is unreasonable to say that there are seminal virtues in corporeal matter.
Obj. 3: Further, seeds are active principles. But there are no active principles in corporeal matter; since, as we have said above, matter is not competent to act (A. 1, ad 2, 4). Therefore there are no seminal virtues in corporeal matter.