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.