Now the will is moved to the end, and to the means to the end; we must therefore consider:  (1) those acts of the will whereby it is moved to the end; and (2) those whereby it is moved to the means.  And since it seems that there are three acts of the will in reference to the end; viz. “volition,” “enjoyment,” and “intention”; we must consider:  (1) volition; (2) enjoyment; (3) intention.  Concerning the first, three things must be considered: 

(1) Of what things is the will?

(2) By what is the will moved?

(3) How is it moved?

Under the first head there are three points of inquiry: 

(1) Whether the will is of good only?

(2) Whether it is of the end only, or also of the means?

(3) If in any way it be of the means, whether it be moved to the end and to the means, by the same movement? ________________________

FIRST ARTICLE [I-II, Q. 8, Art. 1]

Whether the Will Is of Good Only?

Objection 1:  It would seem that the will is not of good only.  For the same power regards opposites; for instance, sight regards white and black.  But good and evil are opposites.  Therefore the will is not only of good, but also of evil.

Obj. 2:  Further, rational powers can be directed to opposite purposes, according to the Philosopher (Metaph. ix, 2).  But the will is a rational power, since it is “in the reason,” as is stated in De Anima iii, 9.  Therefore the will can be directed to opposites; and consequently its volition is not confined to good, but extends to evil.

Obj. 3:  Further, good and being are convertible.  But volition is directed not only to beings, but also to non-beings.  For sometimes we wish “not to walk,” or “not to speak”; and again at times we wish for future things, which are not actual beings.  Therefore the will is not of good only.

On the contrary, Dionysius says (Div.  Nom. iv) that “evil is outside the scope of the will,” and that “all things desire good.”

I answer that, The will is a rational appetite.  Now every appetite is only of something good.  The reason of this is that the appetite is nothing else than an inclination of a person desirous of a thing towards that thing.  Now every inclination is to something like and suitable to the thing inclined.  Since, therefore, everything, inasmuch as it is being and substance, is a good, it must needs be that every inclination is to something good.  And hence it is that the Philosopher says (Ethic. i, 1) that “the good is that which all desire.”

But it must be noted that, since every inclination results from a form, the natural appetite results from a form existing in the nature of things:  while the sensitive appetite, as also the intellective or rational appetite, which we call the will, follows from an apprehended form.  Therefore, just as the natural appetite tends to good existing in a thing; so the animal or voluntary appetite tends to a good which is apprehended.  Consequently, in order that the will tend to anything, it is requisite, not that this be good in very truth, but that it be apprehended as good.  Wherefore the Philosopher says (Phys. ii, 3) that “the end is a good, or an apparent good.”