[I-II.q.8.a.1.arg.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.

[I-II.q.8.a.1.arg.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.

[I-II.q.8.a.1.arg.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.

[I-II.q.8.a.1.sc] Dionysius says (Div. Nom. iv) that "evil is outside the scope of the will," and that "all things desire good."

[I-II.q.8.a.1.co] 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."

[I-II.q.8.a.1.ad.1] The same power regards opposites, but it is not referred to them in the same way. Accordingly, the will is referred both to good and evil: but to good by desiring it: to evil, by shunning it. Wherefore the actual desire of good is called "volition" [In Latin, 'voluntas'. To avoid confusion with "voluntas" (the will) St. Thomas adds a word of explanation, which in the translation may appear superfluous], meaning thereby the act of the will; for it is in this sense that we are now speaking of the will. On the other hand, the shunning of evil is better described as "nolition": wherefore, just as volition is of good, so nolition is of evil.

[I-II.q.8.a.1.ad.2] A rational power is not to be directed to all opposite purposes, but to those which are contained under its proper object; for no power seeks other than its proper object. Now, the object of the will is good. Wherefore the will can be directed to such opposite purposes as are contained under good, such as to be moved or to be at rest, to speak or to be silent, and such like: for the will can be directed to either under the aspect of good.

[I-II.q.8.a.1.ad.3] That which is not a being in nature, is considered as a being in the reason, wherefore negations and privations are said to be "beings of reason." In this way, too, future things, in so far as they are apprehended, are beings. Accordingly, in so far as such like are beings, they are apprehended under the aspect of good; and it is thus that the will is directed to them. Wherefore the Philosopher says (Ethic. v, 1) that "to lack evil is considered as a good."

[I-II.q.8.a.2.arg.1] It would seem that volition is not of the means, but of the end only. For the Philosopher says (Ethic. iii, 2) that "volition is of the end, while choice is of the means."

[I-II.q.8.a.2.arg.2] Further, "For objects differing in genus there are corresponding different powers of the soul" (Ethic. vi, 1). Now, the end and the means are in different genera of good: because the end, which is a good either of rectitude or of pleasure, is in the genus "quality," or "action," or "passion"; whereas the good which is useful, and is directed to and end, is in the genus "relation" (Ethic. i, 6). Therefore, if volition is of the end, it is not of the means.

[I-II.q.8.a.2.arg.3] Further, habits are proportionate to powers, since they are perfections thereof. But in those habits which are called practical arts, the end belongs to one, and the means to another art; thus the use of a ship, which is its end, belongs to the (art of the) helmsman; whereas the building of the ship, which is directed to the end, belongs to the art of the shipwright. Therefore, since volition is of the end, it is not of the means.

[I-II.q.8.a.2.sc] In natural things, it is by the same power that a thing passes through the middle space, and arrives at the terminus. But the means are a kind of middle space, through which one arrives at the end or terminus. Therefore, if volition is of the end, it is also of the means.

[I-II.q.8.a.2.co] The word "voluntas" sometimes designates the power of the will, sometimes its act [See note: above 01, Reply to Obj. 1. Accordingly, if we speak of the will as a power, thus it extends both to the end and to the means. For every power extends to those things in which may be considered the aspect of the object of that power in any way whatever: thus the sight extends to all things whatsoever that are in any way colored. Now the aspect of good, which is the object of the power of the will, may be found not only in the end, but also in the means.

If, however, we speak of the will in regard to its act, then, properly speaking, volition is of the end only. Because every act denominated from a power, designates the simple act of that power: thus "to understand" designates the simple act of the understanding. Now the simple act of a power is referred to that which is in itself the object of that power. But that which is good and willed in itself is the end. Wherefore volition, properly speaking, is of the end itself. On the other hand, the means are good and willed, not in themselves, but as referred to the end. Wherefore the will is directed to them, only in so far as it is directed to the end: so that what it wills in them, is the end. Thus, to understand, is properly directed to things that are known in themselves, i.e. first principles: but we do not speak of understanding with regard to things known through first principles, except in so far as we see the principles in those things. For in morals the end is what principles are in speculative science (Ethic. viii, 8).

[I-II.q.8.a.2.ad.1] The Philosopher is speaking of the will in reference to the simple act of the will; not in reference to the power of the will.

[I-II.q.8.a.2.ad.2] There are different powers for objects that differ in genus and are on an equality; for instance, sound and color are different genera of sensibles, to which are referred hearing and sight. But the useful and the righteous are not on an equality, but are as that which is of itself, and that which is in relation to another. Now such like objects are always referred to the same power; for instance, the power of sight perceives both color and light by which color is seen.

[I-II.q.8.a.2.ad.3] Not everything that diversifies habits, diversifies the powers: since habits are certain determinations of powers to certain special acts. Moreover, every practical art considers both the end and the means. For the art of the helmsman does indeed consider the end, as that which it effects; and the means, as that which it commands. On the other hand, the ship-building art considers the means as that which it effects; but it considers that which is the end, as that to which it refers what it effects. And again, in every practical art there is an end proper to it and means that belong properly to that art.