Thomas Aquinas - Summa Theologica, Part I-II (Pars Prima Secundae)

Reply Obj. 2: Men's acts and choices are in reference to singulars. Wherefore from the very fact that the sensitive appetite is a particular power, it has great influence in disposing man so that something seems to him such or otherwise, in particular cases.

Reply Obj. 3: As the Philosopher says (Polit. i, 2), the reason, in which resides the will, moves, by its command, the irascible and concupiscible powers, not, indeed, "by a despotic sovereignty," as a slave is moved by his master, but by a "royal and politic sovereignty," as free men are ruled by their governor, and can nevertheless act counter to his commands. Hence both irascible and concupiscible can move counter to the will: and accordingly nothing hinders the will from being moved by them at times. ________________________

THIRD ARTICLE [I-II, Q. 9, Art. 3]

Whether the Will Moves Itself?

Objection 1: It would seem that the will does not move itself. For every mover, as such, is in act: whereas what is moved, is in potentiality; since "movement is the act of that which is in potentiality, as such" [*Aristotle, Phys. iii, 1]. Now the same is not in potentiality and in act, in respect of the same. Therefore nothing moves itself. Neither, therefore, can the will move itself.

Obj. 2: Further, the movable is moved on the mover being present. But the will is always present to itself. If, therefore, it moved itself, it would always be moving itself, which is clearly false.

Obj. 3: Further, the will is moved by the intellect, as stated above (A. 1). If, therefore, the will move itself, it would follow that the same thing is at once moved immediately by two movers; which seems unreasonable. Therefore the will does not move itself.

On the contrary, The will is mistress of its own act, and to it belongs to will and not to will. But this would not be so, had it not the power to move itself to will. Therefore it moves itself.

I answer that, As stated above (A. 1), it belongs to the will to move the other powers, by reason of the end which is the will's object. Now, as stated above (Q. 8, A. 2), the end is in things appetible, what the principle is in things intelligible. But it is evident that the intellect, through its knowledge of the principle, reduces itself from potentiality to act, as to its knowledge of the conclusions; and thus it moves itself. And, in like manner, the will, through its volition of the end, moves itself to will the means.

Reply Obj. 1: It is not in respect of the same that the will moves itself and is moved: wherefore neither is it in act and in potentiality in respect of the same. But forasmuch as it actually wills the end, it reduces itself from potentiality to act, in respect of the means, so as, in a word, to will them actually.

Reply Obj. 2: The power of the will is always actually present to itself; but the act of the will, whereby it wills an end, is not always in the will. But it is by this act that it moves itself. Accordingly it does not follow that it is always moving itself.

Reply Obj. 3: The will is moved by the intellect, otherwise than by itself. By the intellect it is moved on the part of the object: whereas it is moved by itself, as to the exercise of its act, in respect of the end. ________________________

FOURTH ARTICLE [I-II, Q. 9, Art. 4]

Whether the Will Is Moved by an Exterior Principle?

Objection 1: It would seem that the will is not moved by anything exterior. For the movement of the will is voluntary. But it is essential to the voluntary act that it be from an intrinsic principle, just as it is essential to the natural act. Therefore the movement of the will is not from anything exterior.

Obj. 2: Further, the will cannot suffer violence, as was shown above (Q. 6, A. 4). But the violent act is one "the principle of which is outside the agent" [*Aristotle, Ethic. iii, 1]. Therefore the will cannot be moved by anything exterior.

Obj. 3: Further, that which is sufficiently moved by one mover, needs not to be moved by another. But the will moves itself sufficiently. Therefore it is not moved by anything exterior.

On the contrary, The will is moved by the object, as stated above (A. 1). But the object of the will can be something exterior, offered to the sense. Therefore the will can be moved by something exterior.

I answer that, As far as the will is moved by the object, it is evident that it can be moved by something exterior. But in so far as it is moved in the exercise of its act, we must again hold it to be moved by some exterior principle.

For everything that is at one time an agent actually, and at another time an agent in potentiality, needs to be moved by a mover. Now it is evident that the will begins to will something, whereas previously it did not will it. Therefore it must, of necessity, be moved by something to will it. And, indeed, it moves itself, as stated above (A. 3), in so far as through willing the end it reduces itself to the act of willing the means. Now it cannot do this without the aid of counsel: for when a man wills to be healed, he begins to reflect how this can be attained, and through this reflection he comes to the conclusion that he can be healed by a physician: and this he wills. But since he did not always actually will to have health, he must, of necessity, have begun, through something moving him, to will to be healed. And if the will moved itself to will this, it must, of necessity, have done this with the aid of counsel following some previous volition. But this process could not go on to infinity. Wherefore we must, of necessity, suppose that the will advanced to its first movement in virtue of the instigation of some exterior mover, as Aristotle concludes in a chapter of the Eudemian Ethics (vii, 14).

Reply Obj. 1: It is essential to the voluntary act that its principle be within the agent: but it is not necessary that this inward principle be the first principle unmoved by another. Wherefore though the voluntary act has an inward proximate principle, nevertheless its first principle is from without. Thus, too, the first principle of the natural movement is from without, that, to wit, which moves nature.

Reply Obj. 2: For an act to be violent it is not enough that its principle be extrinsic, but we must add "without the concurrence of him that suffers violence." This does not happen when the will is moved by an exterior principle: for it is the will that wills, though moved by another. But this movement would be violent, if it were counter to the movement of the will: which in the present case is impossible; since then the will would will and not will the same thing.

Reply Obj. 3: The will moves itself sufficiently in one respect, and in its own order, that is to say as proximate agent; but it cannot move itself in every respect, as we have shown. Wherefore it needs to be moved by another as first mover. ________________________

FIFTH ARTICLE [I-II, Q. 9, Art. 5]

Whether the Will Is Moved by a Heavenly Body?

Objection 1: It would seem that the human will is moved by a heavenly body. For all various and multiform movements are reduced, as to their cause, to a uniform movement which is that of the heavens, as is proved in Phys. viii, 9. But human movements are various and multiform, since they begin to be, whereas previously they were not. Therefore they are reduced, as to their cause, to the movement of the heavens, which is uniform according to its nature.

Obj. 2: Further, according to Augustine (De Trin. iii, 4) "the lower bodies are moved by the higher." But the movements of the human body, which are caused by the will, could not be reduced to the movement of the heavens, as to their cause, unless the will too were moved by the heavens. Therefore the heavens move the human will.

Obj. 3: Further, by observing the heavenly bodies astrologers foretell the truth about future human acts, which are caused by the will. But this would not be so, if the heavenly bodies could not move man's will. Therefore the human will is moved by a heavenly body.