I answer that, It is erroneous to say that God cannot Himself produce all the determinate effects which are produced by any created cause. Wherefore, since bodies are moved immediately by created causes, we cannot possibly doubt that God can move immediately any bodies whatever. This indeed follows from what is above stated (A[1]). For every movement of any body whatever, either results from a form, as the movements of things heavy and light result from the form which they have from their generating cause, for which reason the generator is called the mover; or else tends to a form, as heating tends to the form of heat. Now it belongs to the same cause, to imprint a form, to dispose to that form, and to give the movement which results from that form; for fire not only generates fire, but it also heats and moves things upwards. Therefore, as God can imprint form immediately in matter, it follows that He can move any body whatever in respect of any movement whatever.
Reply to Objection 1: There are two kinds of contact; corporeal contact, when two bodies touch each other; and virtual contact, as the cause of sadness is said to touch the one made sad. According to the first kind of contact, God, as being incorporeal, neither touches, nor is touched; but according to virtual contact He touches creatures by moving them; but He is not touched, because the natural power of no creature can reach up to Him. Thus did Dionysius understand the words, "There is no contact with God"; that is, so that God Himself be touched.
Reply to Objection 2: God moves as the object of desire and apprehension; but it does not follow that He always moves as being desired and apprehended by that which is moved; but as being desired and known by Himself; for He does all things for His own goodness.
Reply to Objection 3: The Philosopher (Phys. viii, 10) intends to prove that the power of the first mover is not a power of the first mover "of bulk," by the following argument. The power of the first mover is infinite (which he proves from the fact that the first mover can move in infinite time). Now an infinite power, if it were a power "of bulk," would move without time, which is impossible; therefore the infinite power of the first mover must be in something which is not measured by its bulk. Whence it is clear that for a body to be moved without time can only be the result of an infinite power. The reason is that every power of bulk moves in its entirety; since it moves by the necessity of its nature. But an infinite power surpasses out of all proportion any finite power. Now the greater the power of the mover, the greater is the velocity of the movement. Therefore, since a finite power moves in a determinate time, it follows that an infinite power does not move in any time; for between one time and any other time there is some proportion. On the other hand, a power which is not in bulk is the power of an intelligent being, which operates in its effects according to what is fitting to them; and therefore, since it cannot be fitting for a body to be moved without time, it does not follow that it moves without time.
Whether God moves the created intellect immediately?
Objection 1: It would seem that God does not immediately move the created intellect. For the action of the intellect is governed by its own subject; since it does not pass into external matter; as stated in Metaph. ix, Did. viii, 8. But the action of what is moved by another does not proceed from that wherein it is; but from the mover. Therefore the intellect is not moved by another; and so apparently God cannot move the created intellect.
Objection 2: Further, anything which in itself is a sufficient principle of movement, is not moved by another. But the movement of the intellect is its act of understanding; in the sense in which we say that to understand or to feel is a kind of movement, as the Philosopher says (De Anima iii, 7). But the intellectual light which is natural to the soul, is a sufficient principle of understanding. Therefore it is not moved by another.
Objection 3: Further, as the senses are moved by the sensible, so the intellect is moved by the intelligible. But God is not intelligible to us, and exceeds the capacity of our intellect. Therefore God cannot move our intellect.
On the contrary, The teacher moves the intellect of the one taught. But it is written ( Ps. 93:10 ) that God "teaches man knowledge." Therefore God moves the human intellect.
I answer that, As in corporeal movement that is called the mover which gives the form that is the principle of movement, so that is said to move the intellect, which is the cause of the form that is the principle of the intellectual operation, called the movement of the intellect. Now there is a twofold principle of intellectual operation in the intelligent being; one which is the intellectual power itself, which principle exists in the one who understands in potentiality; while the other is the principle of actual understanding, namely, the likeness of the thing understood in the one who understands. So a thing is said to move the intellect, whether it gives to him who understands the power of understanding; or impresses on him the likeness of the thing understood.
Now God moves the created intellect in both ways. For He is the First immaterial Being; and as intellectuality is a result of immateriality, it follows that He is the First intelligent Being. Therefore since in each order the first is the cause of all that follows, we must conclude that from Him proceeds all intellectual power. In like manner, since He is the First Being, and all other beings pre-exist in Him as in their First Cause, it follows that they exist intelligibly in Him, after the mode of His own Nature. For as the intelligible types of everything exist first of all in God, and are derived from Him by other intellects in order that these may actually understand; so also are they derived by creatures that they may subsist. Therefore God so moves the created intellect, inasmuch as He gives it the intellectual power, whether natural, or superadded; and impresses on the created intellect the intelligible species, and maintains and preserves both power and species in existence.
Reply to Objection 1: The intellectual operation is performed by the intellect in which it exists, as by a secondary cause; but it proceeds from God as from its first cause. For by Him the power to understand is given to the one who understands.
Reply to Objection 2: The intellectual light together with the likeness of the thing understood is a sufficient principle of understanding; but it is a secondary principle, and depends upon the First Principle.
Reply to Objection 3: The intelligible object moves our human intellect, so far as, in a way, it impresses on it its own likeness, by means of which the intellect is able to understand it. But the likenesses which God impresses on the created intellect are not sufficient to enable the created intellect to understand Him through His Essence, as we have seen above (Q[12], A[2]; Q[56], A[3]). Hence He moves the created intellect, and yet He cannot be intelligible to it, as we have explained (Q[12], A[4]).
Whether God can move the created will?
Objection 1: It would seem that God cannot move the created will. For whatever is moved from without, is forced. But the will cannot be forced. Therefore it is not moved from without; and therefore cannot be moved by God.
Objection 2: Further, God cannot make two contradictories to be true at the same time. But this would follow if He moved the will; for to be voluntarily moved means to be moved from within, and not by another. Therefore God cannot move the will.
Objection 3: Further, movement is attributed to the mover rather than to the one moved; wherefore homicide is not ascribed to the stone, but to the thrower. Therefore, if God moves the will, it follows that voluntary actions are not imputed to man for reward or blame. But this is false. Therefore God does not move the will.
On the contrary, It is written ( Phil. 2:13 ): "It is God who worketh in us [Vulgate---'you'] both to will and to accomplish."
I answer that, As the intellect is moved by the object and by the Giver of the power of intelligence, as stated above (A[3]), so is the will moved by its object, which is good, and by Him who creates the power of willing. Now the will can be moved by good as its object, but by God alone sufficiently and efficaciously. For nothing can move a movable thing sufficiently unless the active power of the mover surpasses or at least equals the potentiality of the thing movable. Now the potentiality of the will extends to the universal good; for its object is the universal good; just as the object of the intellect is the universal being. But every created good is some particular good; God alone is the universal good. Whereas He alone fills the capacity of the will, and moves it sufficiently as its object. In like manner the power of willing is caused by God alone. For to will is nothing but to be inclined towards the object of the will, which is universal good. But to incline towards the universal good belongs to the First Mover, to Whom the ultimate end is proportionate; just as in human affairs to him that presides over the community belongs the directing of his subjects to the common weal. Wherefore in both ways it belongs to God to move the will; but especially in the second way by an interior inclination of the will.
Reply to Objection 1: A thing moved by another is forced if moved against its natural inclination; but if it is moved by another giving to it the proper natural inclination, it is not forced; as when a heavy body is made to move downwards by that which produced it, then it is not forced. In like manner God, while moving the will, does not force it, because He gives the will its own natural inclination.
Reply to Objection 2: To be moved voluntarily, is to be moved from within, that is, by an interior principle: yet this interior principle may be caused by an exterior principle; and so to be moved from within is not repugnant to being moved by another.
Reply to Objection 3: If the will were so moved by another as in no way to be moved from within itself, the act of the will would not be imputed for reward or blame. But since its being moved by another does not prevent its being moved from within itself, as we have stated (ad 2), it does not thereby forfeit the motive for merit or demerit.
Whether God works in every agent?
Objection 1: It would seem that God does not work in every agent. For we must not attribute any insufficiency to God. If therefore God works in every agent, He works sufficiently in each one. Hence it would be superfluous for the created agent to work at all.