I answer that, Command is an act of the reason presupposing, however, an act of the will. In proof of this, we must take note that, since the acts of the reason and of the will can be brought to bear on one another, in so far as the reason reasons about willing, and the will wills to reason, the result is that the act of the reason precedes the act of the will, and conversely. And since the power of the preceding act continues in the act that follows, it happens sometimes that there is an act of the will in so far as it retains in itself something of an act of the reason, as we have stated in reference to use and choice; and conversely, that there is an act of the reason in so far as it retains in itself something of an act of the will.
Now, command is essentially indeed an act of the reason: for the commander orders the one commanded to do something, by way of intimation or declaration; and to order thus by intimating or declaring is an act of the reason. Now the reason can intimate or declare something in two ways. First, absolutely: and this intimation is expressed by a verb in the indicative mood, as when one person says to another: "This is what you should do." Sometimes, however, the reason intimates something to a man by moving him thereto; and this intimation is expressed by a verb in the imperative mood; as when it is said to someone: "Do this." Now the first mover, among the powers of the soul, to the doing of an act is the will, as stated above (Question [9], Article [1]). Since therefore the second mover does not move, save in virtue of the first mover, it follows that the very fact that the reason moves by commanding, is due to the power of the will. Consequently it follows that command is an act of the reason, presupposing an act of the will, in virtue of which the reason, by its command, moves (the power) to the execution of the act.
