Lecture 2 — Function Proper to Each Part of the Soul

We must, then, ascertain what is the most excellent habit of each of these parts, for this is their virtue. [1124]

But virtue is directed to the work that is proper. [1125]

Three things in the soul seem to have power over action and truth: the senses, the intellect, and the appetitive faculty. [1126]

But one of these, the senses, is not a principle of any action. This is obvious because dumb animals have senses but do not share in action. [1127]

Now, affirmation and negation are in the mind, and corresponding to these in the appetitive faculty are pursuit and flight. [1128]

Therefore, if moral virtue is a habit of free choice, and if choice is the appetitive faculty deliberating, then reason must be true and the appetitive faculty right if choice is to be good; and the same things that reason affirms, the appetitive faculty pursues. Hence, this mind and its truth are practical. [1129]

However, it is the function of the speculative mind (but not the practical), as it operates in good or faulty fashion, to express truth and falsity. This belongs to every intellect, but the good of the practical intellect is truth conformable to a right appetitive faculty. [1130]

Choice, then, is a principle of action, and so of motion, but not as a final cause. But, for choice itself, the principles are the appetitive faculty and the reason, which is terminative. Hence, choice does not exist without intellect and mind, nor without moral habit, for good and bad actions cannot exist without the intellect or mind and moral disposition. [1133]

Still, mind itself does not move anything, but the mind that has a purpose and is practical does so, for it governs even the operation that fashions some product. Indeed, every worker produces for the sake of something; he is not induced to act for an end in general, but for a particular thing made for some use; he does not act merely for the sake of acting. The good action itself is an end, but the appetitive faculty is for some particular end. [1135]

Therefore, choice is either the appetitive intellect or the intellective faculty of appetition, and man is this kind of principle. [1137]

What has already taken place is not now an object of choice—for example, no one now chooses to have captured Ilion. Nor does anyone give advice about something past, but about a future and contingent event. It is not possible that what has taken place did not occur. Therefore, Agathon was right, for God lacks only this—to undo things already done. [1138]

In any case, the work of each of the intellect’s parts is the knowledge of the truth. [1140]

These habits according to which each part especially manifests the truth are the virtues of both divisions of the intellect. [1141]

1124. We must, then, ascertain. After the Philosopher has divided the parts of the rational soul as required for his purpose, he now begins to examine the intellectual virtues themselves by which each part of the rational soul is perfected.

First, he considers the particular intellectual virtues.

Second, at someone may raise a doubt (1143b18; [1257]), he expresses a certain doubt about their utility.

On the first point, he does two things.

First, he investigates the ways of understanding the intellectual virtues.

Second, at introducing again the subject (1139b14; [1142]), he sets himself to examine them.

On the first point, he does three things.

First, he proposes the common notion of virtue as stated in the beginning [65, 81]: what renders the work of a thing good is its virtue.

Second, at three things in the soul (1139a18; [1126]), he inquires what the good of the rational soul is in regard to each part.

Third, at these habits according to which (1139b12; [1141]), he infers the nature and quality of the virtues of each part.

1125. He says first that, because we have assigned two parts of the rational soul (to which the intellectual virtues are ascribed), we must understand which is the most excellent habit of each of these two parts. The reason is that each habit is necessarily a virtue of each part. It has been noted [308, 536] that the virtue of anything is directed to its characteristic operation, for this is perfected by virtue. Such a habit would be best when it insures that an action is performed in the best way.

1126. Then, at three things in the soul (1139a18), he inquires what the proper good of each of these parts is.

On this point, he does three things.

First, he shows what the principles of human acts are.

Second, at however, it is the function (1139a27; [1130]), he seeks what the proper work of reason is.

Third, at in any case, the work (1139b12; [1140]), he draws the conclusion he sought to establish.

On the first point, he does three things.

First, he proposes three ingredients that are called principles of human acts.

Second, at but one of these (1139a19; [1127]), he excludes one of them.

Third, at now, affirmation and negation (1139a21; [1128]), he shows how the remaining two can harmonize with each other.

In regard to the first, we must consider that two works are said to be proper to man: knowledge of truth and action, inasmuch as man assumes mastery of his own action (and as moved or led by something). Over these two, then three things in the soul (senses, intellect, and appetitive faculty) seem to have mastery and power. It is by the same three that animals move themselves, as was noted in De anima. (De anima 3.10.433a9; see Aquinas, In III de an., lec. 15, nn. 818–19.)

1127. Next, at but one of these (1139a19), he excludes one of them, the senses, from further consideration. It is certainly obvious that truth pertains neither to the senses nor to the appetitive faculty. He adds further that one of the three, the senses, is not a principle of any action in such a way that mastery of the action can be established. This is clear from the fact that dumb animals have senses but do not have social action, for they are not masters of their own action; they do not operate from themselves, but are moved by natural instinct.

1128. At now, affirmation and negation (1139a21), he shows how the work of the remaining two—intellect and appetitive faculty—can harmonize one with the other.

First, he shows how their actions are proportionable. In judging, the intellect has two actions: affirmation, by which it assents to what is true, and negation, by which it dissents from what is false. To these two correspond proportionately two acts in the appetitive faculty: pursuit, by which the appetitive faculty tends and adheres to good, and flight, by which it withdraws and dissents from evil. In this manner, the intellect and the appetitive faculty can be brought into harmony, inasmuch as what the intellect declares good the appetitive faculty pursues, and what the intellect denies to be good the appetitive faculty seeks to avoid.

1129. Second, at therefore, since moral virtue (1139a22), he shows how these actions of the intellect and appetitive faculty—touching the moral virtues—are in agreement. Moral virtue is a habit of free choice, as was said in book 2 [305, 308] and book 3 [382]. Choice is the appetitive faculty deliberating, inasmuch as the appetitive faculty takes what was preconsidered, as was stated in book 3 [435–36, 457]. But to counsel is an act of one part of the reason, as was previously shown [473, 476, 482, 1118]. Since, then, reason and appetitive faculty concur in choice, if choice ought to be good, which is required for the nature of a moral virtue, then the reason must be true and the appetitive faculty right, so that the same thing that reason declares or affirms the appetitive faculty pursues. In order that there be perfection in action, it is necessary that none of its principles be imperfect. But this intellect or reason (which harmonizes in this way with the right appetitive faculty) and its truth are practical.

1130. Next, at however, it is the function (1139a27), he explains what the work of the rational soul is in terms of each part.

First, he shows how each part is related to truth.

Second, at choice, then, is (1139a31), he shows how each part is related to action.

He says first that the work of a good or faulty mind (that is, intellect or reason) in the speculative rather than practical order consists simply in the true and false, in such a way that the absolutely true is its good and the absolutely false is its evil. To express the true and the false is an essential function of every intellect. However, the good of the practical intellect is not absolute truth, but the conformable truth, that is, corresponding to a right appetitive faculty, as has been shown [22, 326, 548], because the moral virtues are united on this point.

1131. However, there seems to be some difficulty here. If the truth of the practical intellect is determined by comparison with a right appetitive faculty and the rectitude of the appetitive faculty is determined by the fact that it agrees with right reason, as was previously shown, an apparent vicious circle results from these statements. Therefore, we must say that the end and the means pertain to the appetitive faculty but the end is determined for man by nature, as was shown in the book 3 [524–25]. The means, however, are not determined for us by nature, but are to be investigated by reason. So, it is obvious that rectitude of the appetitive faculty in regard to the end is the measure of truth for the practical reason. According to this, the truth of the practical reason is determined by agreement with a right appetitive faculty. But the truth of the practical reason itself is the rule for the rectitude of the appetitive faculty in regard to the means. According to this, then, the appetitive faculty is called “right” inasmuch as it pursues the things that reason calls true.

1132. A further confusion arises here from the manner in which he connects the speculative and practical intellect (as with the two parts given above [1118]) as the scientific and the estimative—since he stated previously [1123] that the scientific and estimative were different parts, a thing he denies about the speculative and practical intellect in De anima. (De anima 3.10.433a15; see Aquinas, In III de an., lec. 15, nn. 820–21.) Therefore, we must say that the practical intellect has a beginning in a universal consideration and, according to this, is the same in subject with the speculative, but its consideration terminates in an individual operable thing. Hence, the Philosopher says in De anima (De anima 3.11.434a16; see Aquinas, In III de an., lec. 16, nn. 845–46.) that universal reason does not move without the particular. In this way, the estimative is considered a different part from the scientific.

1133. At choice, then, is the principle (1139a31), he shows that each reason has a relation to action.

On this point, he does three things.

First, he explains that the mind is a principle of action.

Second, at still, mind itself (1139a35; [1135]), he shows of what mind he speaks.

Third, at what has already taken place (1139b5; [1138]), he explains about what kinds of objects the mind is the active principle.

First, he concludes from what was just said [1129] that, because choice is the appetitive faculty deliberating, it is consequently a principle of action, and so of motion, that is, in the manner of an efficient cause but not for the sake of something, and so rather in the manner of a final cause. We have already said in De anima (De anima 3.10.433b27–31; see Aquinas, In III de an., lec. 15, nn. 836–37.) that the appetitive faculty is a source of movement in animals. But for choice itself, the principles are the appetitive faculty and the reason that is purposive, meaning that which is ordered to a practical thing as to an end, for the choice of the appetitive faculty is concerned with the things that are for the end.

Hence, reason proposing an end and thereupon proceeding to think discursively about it and the appetitive faculty tending to the end are compared to choice as a cause. So it is that choice depends on the intellect and on the moral habit that perfects the appetitive power in such a way that it does not exist without either of them.

1134. He gives a sign in proof of this, for the effect of choice is action, as was pointed out. But the action that is good and its direct opposite in action (that is, the action that is evil) cannot exist without the mind and disposition or moral condition, which is some inclination belonging to the appetitive faculty. Hence, neither does choice, good or bad, exist without disposition and mind.

1135. Then, at still, mind itself (1139a35), he shows what mind or reason is the principle of action.

First, he explains the proposition.

Second, at therefore, choice is either (1139b4; [1137]), he infers a corollary from what has been discussed.

He says first that, although the mind is a principle of action, nevertheless the mind simply considered in itself (or the speculative reason) does not move anything, since it prescribes nothing about pursuit or flight, as was stated in De anima. (De anima 3.9.432b27–33; see Aquinas, In III de an., lec. 14, nn. 812–15.) Hence, it is not the speculative mind that is a principle of action, but the mind having a purpose or ordained to an individual operable thing as an end. This is the practical reason or mind, and it governs not only active operation, which does not pass into external matter but remains in the agent—like desiring and becoming angry—but also factive operation, which does pass into external matter, such as burning and cutting.

1136. He proves this by the fact that every worker, such as the carpenter or builder, makes his product for the sake of something, that is, for an end—not an abstract one, but with a view to some particular thing that is made or established in external matter, such as a knife or a house. Moreover, the end is not something done, such as a practicable thing existing in the agent, like rightly desiring or becoming angry. Every worker acts for the sake of something belonging to a thing, something that has some use, as the use of a house is habitation. This, then, is the end of the worker, something made and not a thing done. Therefore, it is not something done, for in immanent actions, the good action itself is the end: for example, rightly desiring or justly becoming angry. Just as the practical mind is for the sake of this end, either a thing made or an action, so also the appetitive faculty is for the sake of some particular end.

1137. Next, at therefore, choice is either (1139b4), he draws a corollary from the premises. Because choice is a principle of action and the principles of choice are the appetitive faculty and reason (that is, intellect or mind), which by means of choice are principles of action, it follows that choice is of the appetitive intellect (in such a way that choice is essentially an act of the intellect according as it orders the appetitive faculty), or it is of the intellective faculty of appetition (in such a way that choice is essentially an act of the appetitive faculty according as it is directed by the intellect). The latter is nearer the truth, as is clear from the objects. The object of choice, as also of the appetitive faculty, is good and evil but not true and false, which pertain to the intellect as such. A principle of this kind is man, namely, an agent choosing by means of intellect and appetitive faculty.

1138. At what has already taken place (1139b5), he explains the kinds of objects the mind is concerned with as the principle of action by power of choice. He says that nothing over and done with (that is, nothing past) is an object of choice: for instance, no one chooses Ilion, that is, to have captured Troy. The reason is that choice belongs to the deliberating faculty of appetition, as already noted [1129, 1133].

No one takes counsel about something done (that is, about a past event), but about a future and contingent one. He proves this from the fact that counsel is given only about a contingent event, as shown previously [460–72]. Now, what was done is not contingent, since it is not possible that the thing becomes undone, that it did not take place. Here he introduces the words of Agathon, who rightly remarked, “God lacks only this power: to cause things to be unproduced,” that is, to make things that are already made not made. This was well said.

1139. Everything that can be contained under the proper object of any cause’s capacity is necessarily subjected to the influence of that cause: for instance, fire can heat anything capable of becoming hot. But the power of God, who is the universal cause of being, extends to the totality of being.

Hence, that only is withdrawn from the divine power that is inconsistent with the nature of being, as something that implies a contradiction. That a thing done be undone is of this kind, since it involves the same formality for a thing to be while it is and to have been while it was; and for what is, not to be, and for what was, not to have been.

1140. Next, at in any case the work (1139b12), he infers from the premises that knowledge of the truth is the work of each part of the intellect, namely, the practical and the speculative or the scientific and the estimative.

1141. Then, at these habits according to which (1139b12), he deduces lastly that those habits by which the truth—the good of the intellective part—is manifested are virtues of both divisions of the intellect.