Article 10 — Whether the will and the intellect are one power

Tenth, it is asked whether the will and the intellect are one power. (Parallel text: ST, I.80.1; I.82.3)

Obj. 1: It seems that they are, for powers are distinguished according to objects, but the object of the intellect is truth and that of the will is goodness. (From objects: Aristotle, On the Soul 2.6, 415a18; as referred to by Aquinas, In I Sent., d. 48, a. 2, obj. 2, In II Sent., d. 38, a. 4, obj. 1; power through act: Aristotle, here above as referred to by Aquinas, In II Sent., d. 24, q. 1, a. 2, obj. 3; In IV Sent., d. 18, q. 1, a. 1, qa. 2.) Therefore, since goodness and truth are the same in subject and differ according to reason, it seems that the intellect and the will are the same in reality though they differ only according to reason.

Obj. 2: Furthermore, according to the Philosopher in On the Soul, (Aristotle, On the Soul 3.14, 432b5.) the will is within reason. Therefore, it is either the same as reason or it is a part of reason. But reason is the same power as the intellect, thus also the will.

Obj. 3: Furthermore, the powers of the soul are commonly divided into the rational, the concupiscible, and the irascible, (Vires . . . irascibile: according to Plato as referred by Averroes, On the Soul, bk. 3, comm. 41; Jerome, Commentary on Ezekiel, bk. 1, ch. 1 (PL 25:22A-B).) but the will is distinguished from the irascible and the concupiscible, thus, it is contained under the rational.

Obj. 4: Furthermore, wherever one finds the same object in reality and in reason, there is also one power. But for both the will and the practical intellect there is the same object in reality and in reason, for goodness seems to be the object of both. Therefore, the practical intellect is not a power other than the will. But the speculative intellect is not a different power than the practical since, according to the Philosopher in On the Soul, (Aristotle, On the Soul 3.9, 433a1. Sec. transl. veterem (ed. Alonso, p. 355,14).) the speculative becomes practical by extension. Therefore, the will and intellect are simply one power.

Obj. 5: Furthermore, just as in order to know the difference between two things it is necessary that the same person knows both of the things whose difference he considers, so also is it necessary that the same person both knows and wills. But in order to know the difference between two things, such as between sweetness and whiteness, the same power must know both of them, from which the Philosopher proves in On the Soul, (Aristotle, On the Soul 3.2, 426b12.) that there is a common sense. Thus, for the same reason, there must be one power that knows and wills, so that the intellect and the will are one power, as it seems.

On the contrary (1) is that the appetitive class of soul is other than the intellective, according to the Philosopher. (Cf. Aristotle, De anima 2.5, 414a31; ibid. 3.15, 433a31.) but the will is contained under the appetitive. Therefore, the will is a power other than the intellect.

Furthermore (2), the intellect can be forced, according to the Philosopher in the Metaphysics, (Aristotle, Metaphysics 5.6, 1015b6.) but the will cannot be forced, as was said. Therefore, the intellect and the will are not one power.

I answer that it must be said that the will and the intellect are diverse powers, pertaining also to diverse kinds of powers. In evidence of this it must be known that since powers are distinct with regard to acts and objects, not just any difference of objects manifests a diversity of powers, but rather the difference of objects as objects, but not any accidental difference that happens to an object as object. For it happens to the sensible as sensible to be ensouled or unensouled, even though for the things themselves that sense, these differences are essential. Therefore, sensitive powers are not distinguished with regard to these differences, but with regard to the audible, the visible, and the tangible, which are differences of the sensible as sensible, whether by being sensible through a medium or without a medium. When, however, the essential differences of objects as objects are taken up as essentially dividing some special object of the soul, the powers are diversified by this, but not the kinds of powers, so that the sensible does not denote the soul's object, simply, but a certain object that is essentially divided by the previously mentioned differences. Hence vision, hearing, and sight are different individual powers belonging to the same genus of the soul's powers, namely, to sense. But when the selected differences divide the object itself, taken commonly, then from such a difference diverse kinds of powers are made known.

However, something is called an object of the soul inasmuch as it has some relationship to the soul. Therefore, wherever we find diverse notions of relation to the soul, we find an essential difference of the soul's object, demonstrating a different genus of the soul's powers. However, things have a twofold relationship to the soul, one inasmuch as the thing itself is within the soul by the soul's mode and not by its own mode, another inasmuch as the soul is compared to the thing existing in its own being. And so the soul's object is something in two ways: in one way inasmuch as it is such as to be in the soul not according to its own being but according to the soul's mode, that is, spiritually, and this is the notion of the knowable as knowable; in another way something is the soul's object inasmuch as the soul is inclined and ordered toward it according to the mode of the thing existing in itself, and this is the notion of the desirable as desirable. Hence, knowing and desiring within the soul constitute diverse kinds of powers. Thus, since the intellect is contained under knowing but the will under desiring, the will and intellect must also be generically diverse powers.

Reply Obj. 1: To the first, therefore, it must be said that the distinction among powers is not shown from the objects considered according to reality, but rather according to reason: for the very notions of the objects specify the power's operations themselves. Thus, we find that wherever there is a diverse notion of an object there is a diverse power, even though it is the same thing that lies under each notion, as in the case of goodness and truth. This is also clear in material things, for air suffers from fire inasmuch as it is hot with respect to its being potentially hot air. But inasmuch as fire is luminous, air suffers from it according to its being transparent, and neither is it the same potency in air by which it is said to be transparent and potentially hot, even though it is the same fire that acts upon each potency.

Reply Obj. 2: To the second it must be said that potency can be considered in two ways, either as ordered to an object or as ordered to the essence of the soul in which it is rooted. Thus, if the will should be considered as ordered to an object, then it pertains to another power of the soul than the intellect, and thus the will is distinguished against reason and intellect, as was said. But if the will should be considered with regard to that in which it is rooted, then since the will has no bodily organ, as neither does the intellect, the will and the intellect are reduced to the same part of the soul. Thus, the terms "intellect" or "reason" are sometimes taken as including both within itself; and in this sense the will is said to be within reason, and in this respect the rational power, including both intellect and will, is dived against the irascible and the concupiscible.

Reply Obj. 3: And from this the solution to the third is clear.

Reply Obj. 4: To the fourth it must be said that the object of the practical intellect is not goodness, but truth as related to work.

Reply Obj. 5: To the fifth it must be said that to will and to know are not acts of one faculty of reason, and therefore they cannot pertain to one power, as to know sweetness and whiteness, hence, the argument is not similar.