Reply Obj. 2:  Just as each of the members of the body works not for itself alone but for the whole body; thus it is for the whole body that the eye sees; so is it with the powers of the soul.  For the intellect understands, not for itself alone, but for all the powers; and the will wills not only for itself, but for all the powers too.  Wherefore man, in so far as he is endowed with intellect and will, commands the act of the will for himself.

Reply Obj. 3:  Since command is an act of reason, that act is commanded which is subject to reason.  Now the first act of the will is not due to the direction of the reason but to the instigation of nature, or of a higher cause, as stated above (Q. 9, A. 4).  Therefore there is no need to proceed to infinity. ________________________

SIXTH ARTICLE [I-II, Q. 17, Art. 6]

Whether the Act of the Reason Is Commanded?

Objection 1:  It would seem that the act of the reason cannot be commanded.  For it seems impossible for a thing to command itself.  But it is the reason that commands, as stated above (A. 1).  Therefore the act of the reason is not commanded.

Obj. 2:  Further, that which is essential is different from that which is by participation.  But the power whose act is commanded by reason, is rational by participation, as stated in Ethic. i, 13.  Therefore the act of that power, which is essentially rational, is not commanded.

Obj. 3:  Further, that act is commanded, which is in our power.  But to know and judge the truth, which is the act of reason, is not always in our power.  Therefore the act of the reason cannot be commanded.

On the contrary, That which we do of our free-will, can be done by our command.  But the acts of the reason are accomplished through the free-will:  for Damascene says (De Fide Orth. ii, 22) that “by his free-will man inquires, considers, judges, approves.”  Therefore the acts of the reason can be commanded.

I answer that, Since the reason reacts on itself, just as it directs the acts of other powers, so can it direct its own act.  Consequently its act can be commanded.

But we must take note that the act of the reason may be considered in two ways.  First, as to the exercise of the act.  And considered thus, the act of the reason can always be commanded:  as when one is told to be attentive, and to use one’s reason.  Secondly, as to the object; in respect of which two acts of the reason have to be noticed.  One is the act whereby it apprehends the truth about something.  This act is not in our power:  because it happens in virtue of a natural or supernatural light.  Consequently in this respect, the act of the reason is not in our power, and cannot be commanded.  The other act of the reason is that whereby it assents to what it apprehends.  If, therefore, that which the reason apprehends is such that it naturally assents thereto, e.g. the first principles, it is not