Reply Obj. 1:  If the distinct powers are not ordained to one another, their acts are diverse simply.  But when one power is the mover of the other, then their acts are, in a way, one:  since “the act of the mover and the act of the thing moved are one act” (Phys. iii, 3).

Reply Obj. 2:  The fact that command and the commanded act can be separated from one another shows that they are different parts.  Because the parts of a man can be separated from one another, and yet they form one whole.

Reply Obj. 3:  In those things that are many in parts, but one as a whole, nothing hinders one part from preceding another.  Thus the soul, in a way, precedes the body; and the heart, the other members. ________________________

FIFTH ARTICLE [I-II, Q. 17, Art. 5]

Whether the Act of the Will Is Commanded?

Objection 1:  It would seem that the act of the will is not commanded.  For Augustine says (Confess. viii, 9):  “The mind commands the mind to will, and yet it does not.”  But to will is the act of the will.  Therefore the act of the will is not commanded.

Obj. 2:  Further, to receive a command belongs to one who can understand the command.  But the will cannot understand the command; for the will differs from the intellect, to which it belongs to understand.  Therefore the act of the will is not commanded.

Obj. 3:  Further, if one act of the will is commanded, for the same reason all are commanded.  But if all the acts of the will are commanded, we must needs proceed to infinity; because the act of the will precedes the act of reason commanding, as stated above (A. 1); for if that act of the will be also commanded, this command will be preceded by another act of the reason, and so on to infinity.  But to proceed to infinity is not possible.  Therefore the act of the will is not commanded.

On the contrary, Whatever is in our power, is subject to our command.  But the acts of the will, most of all, are in our power; since all our acts are said to be in our power, in so far as they are voluntary.  Therefore the acts of the will are commanded by us.

I answer that, As stated above (A. 1), command is nothing else than the act of the reason directing, with a certain motion, something to act.  Now it is evident that the reason can direct the act of the will:  for just as it can judge it to be good to will something, so it can direct by commanding man to will.  From this it is evident that an act of the will can be commanded.

Reply Obj. 1:  As Augustine says (Confess. viii, 9) when the mind commands itself perfectly to will, then already it wills:  but that sometimes it commands and wills not, is due to the fact that it commands imperfectly.  Now imperfect command arises from the fact that the reason is moved by opposite motives to command or not to command:  wherefore it fluctuates between the two, and fails to command perfectly.