Commentaria in Summam contra Gentiles, Liber II

After Saint Thomas has shown that there had to be in the universe certain creatures that were intellectual, he now determines concerning the nature of these intellectual substances themselves ¹. Concerning this, however, he does two things: first, he determines their nature absolutely; second, by comparison with the esse of actual existence, at chapter LII.

Concerning the first, he does two things: first, he determines their nature with respect to those things that are affirmed of them; second, with respect to those things that are signified negatively, chapter 49.

As to the first, he does two things: first, he shows that willing beings exist; second, that they possess free will, in the following chapter.

I. As to the first, this conclusion is laid down: Created intellectual substances must necessarily be willing.

It is proved first. They have an appetite for the good: because all things desire the good. Therefore they are willing. — The consequence is evident. Because the appetite proper to those that understand is a rational appetite, which is the will: just as the appetite of things lacking cognition is called natural; and the appetite of brute animals is called an animal appetite.

Note, concerning this distinction of appetites, that the appetite following upon a form receives its species and denomination from the form which it follows. Since, therefore, in things lacking cognition it follows upon a merely natural form, in them the appetite is called natural. But in brute animals, and in human beings insofar as they share with brutes, because it follows upon a form apprehended by sense—namely as regards actual inclination—and upon an intrinsic sensitive power as regards potential inclination, it is called the sensitive appetite or animal appetite. In those possessing intellective cognition it is called intellectual, because it follows upon the intellective power and cognition. And it has also received another name, namely that it be called will.

II. Second. There are found in created substances certain things that do not move themselves to act but are moved as natures: plants and brute animals, for instance. Therefore there must be some first things that move themselves to act. Therefore it is necessary that some first things be willing. Therefore intellectual substances are willing. — The first consequence is proved: because what is by another is reduced to what is by itself, as to something prior. This is proved by the example of movable bodies, which are reduced to the first bodies that move themselves; and by conclusions in syllogisms, which are reduced to the first principles known through themselves. — The second is also evident: because it is proper to the will that through it a thing moves itself to act, since through it the substance is mistress of its own acts, as able to act and not to act. — The last is also evident: because the first among created things are intellectual substances.

III. Third ². The form understood, through which the intellectual substance operates, is from the intellect itself, as conceived and in a certain manner devised by it. Therefore intellectual substances act of themselves toward operating, as having dominion over their own operation. Therefore they are willing.

The antecedent is proved by the example of the form of an art, which is devised by the craftsman.

The first consequence is proved. For since an agent acts through a form, the mode of operation must correspond to the mode of the form: namely, a form that is not from the agent itself acting through that form causes an operation of which the agent is not master; whereas a form that is from the agent through the very same form causes an operation of which the agent is master. This is made clear by running through the forms that are principles of action. Natural forms are not from those whose forms they are, but entirely from external agents; and therefore things moved naturally do not move themselves, as is evident in heavy bodies, which are moved by their generator. Similarly, sensed or imagined forms, which move in brute animals, are not devised by the brutes themselves, but are received in them from external sensible objects and judged by natural estimation. And therefore, although they are said to move themselves in a certain way, inasmuch as one part in them moves and another is moved, nevertheless their being moved is not from themselves, but partly from external sensibles and partly from nature.

2. Note, concerning the antecedent, that Saint Thomas says the form is in a certain way thought out by the intellect, but not simply thought out, because, strictly speaking, to think does not belong to the intellect but to the cogitative power; and therefore, strictly speaking, the form of the intellect cannot be said to be thought out. But because the cogitative power, since it is joined to the intellect, participates in something of the intellect by discoursing about particulars, therefore names are sometimes transferred from one to the other by way of similitude, so that the cogitative power is said to understand particulars and the intellect to think. And thus, transferredly, the form conceived by the intellect can be said to be thought out, although this is not said properly; and for this reason Saint Thomas added "in a certain way."

It must also be noted that, since operation follows upon form, it is necessary that the one who gives the form also gives the operation. For this reason it is said that the one who gives the form also gives the motion consequent upon the form: just as the one who gives gravity gives the motion downward. Hence Saint Thomas rightly says that a form which is not from the agent itself (but, namely, is given to it by another) does not cause an operation of which the agent itself is master by means of such a form; rather, the consequent operation is referred as to its principal agent to the one who gives the form. But if an agent causes in itself the form by which it acts, it will be the principal cause of its own action, and will be master of its own acts.

IV. But concerning the declaration of St. Thomas on the moving form in brute animals and the intelligible nature, a twofold doubt arises. The first is that there seems to be no difference between the brute animal and man with respect to the form by which each acts: the opposite of which is stated here. For just as the sensed and imagined forms by which brutes are moved are caused by external sensibles through the mediation of the exterior senses, so too are the forms of the intellect, since our intellectual cognition has its origin in sense ³. Therefore in both natures the form that is the principle of operation and motion is from without.

The second doubt ⁴ is this: because the opposite of what is said here seems to be held in the Prima, q. XVIII, a. 3. For there it is said that animals move themselves with respect to the form which is the principle of motion, which they acquire through themselves, in which they differ from plants, which have their form from another. Therefore they do not have their form from an extrinsic source only, as is said here.

V. To the first doubt it is answered that, although the intelligible species that precedes intellection is caused by exterior sensible things through the mediation of the phantasm (with the agent intellect nevertheless concurring as principal agent), just as are the imagined forms; nevertheless the very form according to which the appetite of intellectual nature is moved immediately and proximately is not caused by any other agent than by the intellective being itself. For the agent forms in itself through the intellect, by an act of understanding, the form of a thing fitting or unfitting, which is called the concept of the intellect: this the imagination of a brute does not do, in which the form of what is fitting or unfitting is caused by another. Likewise the judgment by which something is judged fitting or unfitting is free in intellectual nature, and is no more determined to one side than to the other, but the intellectual agent determines itself: in brutes, however, it is determined by the giver of nature. And because the appetite follows the form of the desirable thing together with the judgment joined to it by which it is judged fitting or unfitting—since brutes have both the form and the judgment determined by another, while intellectual nature has both from itself—it is fittingly said that the forms moving brutes are caused by another, but in intellectual nature by the intellect itself.

VI. To the second doubt ⁵ it is answered, and it is said first that the imagined form by which brute animals are moved, as regards its entity, is not caused by the brute animal but by an extrinsic sensible thing; yet as regards its actual cognition, according to which the form itself is said to be perfectly and completely in act, it is caused also by the sense of the animal, because in the action of sensing the sense itself also concurs actively. And in this sense it is said in the First Part that animals move themselves as regards the form: because the form of a sensible thing is not an actual principle of motion except while it is in perfect act—that is, except insofar as judgment about the sensible thing is made through it; and thus the sense itself is in some way the cause of its own form. Here, however, Saint Thomas speaks of the very entity of the form considered in itself and as regards its imperfect esse, which we have said is caused only by the exterior sensible thing.

It is said second, that the form which is in brute animals, although with respect to its complete esse—which is such that by it judgment is made in act—is in some way from sense, is nevertheless not wholly from sense as it has the character of a motive principle: because with respect to the determination of the judgment by which something is judged suitable or harmful, which is required in animal motion, it depends on another, namely on nature. Now Saint Thomas speaks here of the form with respect to all that belongs to it as it is the principle of motion: and consequently of the form of sense also with respect to the determination of judgment. Hence he does not contradict what is said in the First Part, where there is question of the motive form of the animal only with respect to the complement of its esse, but not with respect to every condition belonging to it as it has the character of a moving form.

A third answer is possible: that the sensible or imagined forms, namely those received in the interior senses, and by which through the imaginative or estimative power some suitable or harmful sensible thing is judged, are impressed from the exterior senses upon the interior powers. And thus brute animals are said to cause such forms in themselves: insofar as, namely, through the exterior senses they impress them upon the interior sense. In this sense what was adduced from the First Part is to be understood. Yet they are not freely devised and contrived by the act of imagination itself or of the estimative power, but are caused by a certain natural order from the senses. In this sense what Saint Thomas says here is to be understood.

VII. Concerning what is said, that being moved does not belong to brute animals of themselves, there is doubt. For it is said in Book VIII of the Physics, text and commentary 29 ⁶, that in everything which moves itself there is both being moved and not being moved; and Aristotle there calls self-movers those things which are divided into a moving part and a moved part, and he calls animals self-movers.

It is answered, according to the doctrine of St. Thomas, Verit., q. XXIV, a. 2, ad 2, that things which move themselves are said both to be moved and not to be moved, not because it lies within their freedom to be moved or not to be moved, but because their motive power, considered in itself, is no more inclined toward one of the opposites than toward the other. Yet because the judgment by which the motive power is applied to one of the opposites rather than the other is determined by nature in brute animals, therefore to be moved is not in brutes absolutely, as though it were within their power whether they move themselves or not: for just as a sheep cannot judge that the wolf ought not be fled from, so it cannot not flee. Hence the motive power in itself is indifferent to fleeing and not fleeing; but the judgment is determined and limited by nature. And since indeterminacy on both sides is required for something properly to be said to have being moved within its own power, therefore brutes do not properly possess moving themselves from themselves, in whom the judgment is determined by nature. And St. Thomas speaks in this sense at this place.

VIII. Fourth ⁷. Intellectual apprehension is not determined to certain things, but is of all things. Therefore the appetite of an intellectual substance is directed toward all things. Therefore it is will. — The antecedent is proved: because in III De Anima it is said that the possible intellect is that by which all things become. — The first consequence is also proved: because the apprehensive power is related to appetite as the mover to the movable. But the active must be proportioned to the passive, and the mover to the movable. — The second consequence is also proved: because it is proper to the will to be directed toward all things; for it extends to possibles and impossibles, as is said in III Ethics.

Note that the will is said to be of impossible things, not insofar as they are impossible, but insofar as they are proposed to it under the aspect of possible things. — Or the will is said to be of impossible things under a condition: namely, because it would will those things if they were possible.