Reply Obj. 2:  An irrational animal takes one thing in preference to another, because its appetite is naturally determinate to that thing.  Wherefore as soon as an animal, whether by its sense or by its imagination, is offered something to which its appetite is naturally inclined, it is moved to that alone, without making any choice.  Just as fire is moved upwards and not downwards, without its making any choice.

Reply Obj. 3:  As stated in Phys. iii, 3 “movement is the act of the movable, caused by a mover.”  Wherefore the power of the mover appears in the movement of that which it moves.  Accordingly, in all things moved by reason, the order of reason which moves them is evident, although the things themselves are without reason:  for an arrow through the motion of the archer goes straight towards the target, as though it were endowed with reason to direct its course.  The same may be seen in the movements of clocks and all engines put together by the art of man.  Now as artificial things are in comparison to human art, so are all natural things in comparison to the Divine art.  And accordingly order is to be seen in things moved by nature, just as in things moved by reason, as is stated in Phys. ii.  And thus it is that in the works of irrational animals we notice certain marks of sagacity, in so far as they have a natural inclination to set about their actions in a most orderly manner through being ordained by the Supreme art.  For which reason, too, certain animals are called prudent or sagacious; and not because they reason or exercise any choice about things.  This is clear from the fact that all that share in one nature, invariably act in the same way. ________________________

THIRD ARTICLE [I-II, Q. 13, Art. 3]

Whether Choice Is Only of the Means, or Sometimes Also of the End?

Objection 1:  It would seem that choice is not only of the means.  For the Philosopher says (Ethic. vi, 12) that “virtue makes us choose aright; but it is not the part of virtue, but of some other power to direct aright those things which are to be done for its sake.”  But that for the sake of which something is done is the end.  Therefore choice is of the end.

Obj. 2:  Further, choice implies preference of one thing to another.  But just as there can be preference of means, so can there be preference of ends.  Therefore choice can be of ends, just as it can be of means.

On the contrary, The Philosopher says (Ethic. iii, 2) that “volition is of the end, but choice of the means.”

I answer that, As already stated (A. 1, ad 2), choice results from the decision or judgment which is, as it were, the conclusion of a practical syllogism.  Hence that which is the conclusion of a practical syllogism, is the matter of choice.  Now in practical things the end stands in the position of a principle, not of a conclusion, as the Philosopher says (Phys. ii, 9).  Wherefore the end, as such, is not a matter of choice.