Commentaria in Summam contra Gentiles, Liber III

After St. Thomas has set forth the conditions of beatitude pertaining to the side of the intellect, he wishes next to determine concerning its conditions pertaining to the side of the object known ¹.

I. And he lays down two conclusions ². The first of which is this: It is impossible for a created intellect to comprehend the divine essence. Furthermore, he first proves this conclusion; secondly, he explains it ³.

As to the first, he argues thus in the first place. It is impossible for a created intellect to see the divine substance as perfectly as it is perfectly visible. Therefore, it is impossible for it to comprehend the same.

The antecedent is proved. The mode of the divine vision is commensurate with the power of the light of glory: since it is a certain principle of divine cognition, and the mode of any action follows the efficacy of its active principle. But this light falls short of the power and clarity of the divine intellect: since the latter is infinite, and the light is finite. Therefore, through it the divine substance is not seen as perfectly as the divine intellect sees it. But the divine intellect sees it as perfectly as it is perfectly visible: since the truth of the divine substance and the clarity of the divine intellect are equal, indeed are one. Therefore, etc.

The consequence, in turn, is proved. Because everything that is comprehended by any knower is known as perfectly as it is knowable. — This is explained from the cognition that is had of a triangle.

2. It must be noted that the proposition assumed here, namely, The mode of any action follows the efficacy of the active principle, in the present context is understood not of the efficacy of the formal principle actuating the potency, which in some way is active, as is the cognitive power, because concerning this another reason will be framed ⁴: but of the efficacy of the principle pertaining to the side of the potency actuatable through the form. For in this way the light of glory is related to the divine vision. For inasmuch as it elevates the intellect to that cognition, and disposes it to the reception of the divine essence by mode of an intelligible species, it pertains to the side of the intellective potency, and according to its measure is the efficacy of the intellect for understanding, and the mode of the divine vision: because it is necessary that the operation be modified not only from the efficacy of the form, but also from the efficacy of the intellective potency.

II. Secondly. The divine substance is a kind of infinite in comparison to every created intellect, that is, in the character of an intelligible object. Therefore, the vision of no created intellect can equal the divine substance in seeing: namely, by seeing it as perfectly as it is visible. Therefore, etc.

The antecedent is proved. Because a finite power, of which kind is a created intellect, which is determined under a certain species, cannot in its operation equal an infinite object.

It must be observed, when St. Thomas speaks here of the finite power of the created intellect, that he does not take its natural power merely, but that power as it is also invigorated through the light of glory: because, since the light of glory is in itself of finite power, it cannot elevate the intellect to being of infinite power in understanding, but it always remains of finite power. And consequently it always remains unequal to the infinitely knowable object: although through such a light it has been made proportioned to that object, so that it can be intelligibly actuated by it. For not everything proportioned to another is equaled to it: just as the primary matter of these lower things is proportioned to receiving each lower substantial form, yet it is not equaled to each one, but, while it has one, it remains still capable of another substantial form.

III. Thirdly. The created intellect does not grasp the divine essence, which is the intelligible form by which it is seen, according to its whole power. Therefore, etc. — The consequence is proved. Because every agent acts so far perfectly, as it perfectly participates the form which is the principle of action.

For the evidence of the antecedent, it must be considered, from the doctrine of St. Thomas, Verit., q. VIII, a. 2, ad 3; and In IV Sent., d. XLIX, q. II, a. 3, ad 6, that we must speak in one way of the divine essence considered in itself: and in another way of it according as it is united to the intellect. For if it be considered in itself, then it is of its own nature suited to cause perfect knowledge: because it is not only most similar to itself, but is also the same, and in itself is an intelligible form in actu. But if it be considered according as it is united to the intellect, thus according to the mode of union it also produces cognition of itself: because then intellection is considered as the operation not of it alone, but of the composite of the intellect and itself in esse intelligibili. For if it is united to the intellect according to its whole power, as it is united to the divine intellect, which is of infinite power, and is most proportioned to it through uncreated and infinite light; thus it produces total and complete knowledge of itself, so that it is known as much as it is knowable. If, however, it is not united to the intellect according to its whole power, it does not produce complete and all-embracing cognition of itself. But it is thus related to every created intellect: for, since it is a subsistent form, it has one mode inasmuch as it is a certain subsistent thing, and another according as it is the act of such a subject. Which does not belong to an accidental form, which does not have in itself another mode from the mode which it has in its subject. But this mode of it, according as it is the act of the intellect, is according as the intellect reaches to being perfected through it. But it is not perfected except by means of a created and finite light. Therefore, it cannot be united to it according to its whole power, which is infinite. And consequently it cannot through it understand it in an infinite mode, in which it is knowable: but according to a greater or lesser participation of the said light, it is more or less united to it, and is more perfectly or more imperfectly seen.

It must also be noted that this reason differs from the first. Because the first proceeded from the efficacy of the productive principle pertaining to the side of the potency in itself: but this one proceeds from the participation of the form, which is the formal principle of the operation.

2. Fourthly. Then the divine substance would not exceed the limits of the created intellect. Because nothing comprehended exceeds the limits of the one comprehending: whether, I say, in the comprehension of dimensive quantity, or in the comprehension of virtual quantity. But this is impossible. Therefore, etc.

IV. As to the second, St. Thomas explains the conclusion ⁵: saying that the divine substance is not understood as not being comprehended by a created intellect as if something of it were seen and something were not seen: but because it is not seen as perfectly as it is visible; in which mode someone is said not to comprehend a demonstrative conclusion of which he has only an opinion, because he does not know it perfectly, namely through science, although there is no part of it which he does not know.

2. For the evidence of this explanation, it must be considered, from the doctrine of St. Thomas in the places cited above, and Prima Pars, q. XII, a. 7, ad 3, that, since the divine essence is altogether simple, and there is nothing of diversity in it, it cannot be seen by the Blessed without being wholly seen, as is also said here; nor can there be any real mode in it which is hidden from the Blessed. Therefore, when it is said that it is not united to the created intellect according to its whole power, or according to its every mode; and that it is not known as perfectly as it is knowable; the meaning is not that there is any real mode of the divine essence which is not united to the intellect, and that there is any mode of God which is not seen, on account of which it would be said to be known imperfectly by us; on the contrary, one who sees God sees His every mode, and sees that He exists infinitely and that He is infinitely knowable: but it is understood thus, that the created intellect does not reach the mode of the divine essence fully while it is actuated by it in esse intelligibili, but is actuated in a lower mode than it is of its own nature suited to actuate in itself, because it is actuated imperfectly according to the disposition of the created light existing in the intellect itself. Whence indeed according to its whole power, and according to its every mode, materially, or taken as to the entity of its power itself and as to the entity of its mode, it is united to the intellect of the Blessed, since its power and its mode is its essence: but it is not united formally according to its whole power and according to its every mode, because it is not united according to every relation that is imported by the name power and by the name mode of its intellectuality. For in itself, it can cause infinite intellection: but it is not united to the created intellect according to a relation to infinite intellection, but according to a relation to finite intellection. And from this it arises that the mode of the object in itself is not proportioned to the mode of the knower: on the contrary, the mode of the knower is far lower than the mode of the object, since the object itself is infinitely knowable, while the intellect, in seeing God, understands Him not infinitely, but finitely; which comes about from the imperfection of the created intellect, but not from a defect of the divine nature. And it is similar as if we were to say, to use the example of St. Thomas in the Prima Pars ⁶, that someone knows probably that a certain conclusion is demonstrable, although he does not know it demonstratively, but by probable reason. For then he knows it imperfectly, not because he is ignorant of any part of that proposition, or of any mode of its knowability: but because his mode in knowing is more imperfect than the mode of knowability of the proposition, since he knows it only probably, while it is knowable not only probably, but also demonstratively. Whence, when it is said that the intellect of the Blessed does not see God in the mode in which He is knowable, it is understood in this sense, that the mode of the intellect in understanding does not equal that mode in which God is knowable in Himself.