Commentaria in Summam contra Gentiles, Liber I

The seventh conclusion, answering the seventh objection, is: God knows evils ¹. Concerning this, Saint Thomas does three things: first, he proves it; second, he explains it ²; third, he removes certain doubts ³.

I. As to the first, it is argued first. God knows all the particular goods to which evils are opposed. Therefore, etc. — The consequence is evident. For, once the good is known, the evil opposed to it is known, as will be declared below ⁴

Second. In God there is the form by which evil is known. Therefore, etc. — The antecedent is proved. The form by which evil is known is not repugnant to good. Indeed, it pertains all the more to the notion of good: namely, insofar as that very form is itself a certain good; since the notions of contraries are not contrary in the soul, otherwise they would not be simultaneously in the soul nor known simultaneously. But in God, on account of His absolute perfection, are found all the forms of goodness. Therefore, etc.

Attend to that implicitly stated proposition, "The reasons of contraries are known together by the soul," which must be understood not as though they were altogether distinct, since, as was shown above ⁵, our intellect cannot understand several things at once as they are several; but as they agree in one intention of contrariety. For the intellect, in understanding that white and black are contraries, understands white and black together, in that respect.

Concerning that proposition, "In God there is the ratio by which evil is known," a doubt is raised. For Saint Thomas holds, Verit., q. III, a. 4 ⁶, that no form of evil can be conceived either in the intellect or in the imagination. Therefore in God there is not the ratio by which evil is known.

It is said that neither in our intellect nor in the divine intellect is there a ratio of evil entirely distinct from the ratio of good. But it can well be a ratio that in some way includes the ratio of good. Therefore there is no contradiction. How this is so will be shown below ⁷

III. Third. The divine intellect cannot lack any of the intellectual perfections. But the good of the intellect consists also in the knowledge of evil. Therefore, and so on. — The minor is proved. It is true that the good of the intellect is a good. But it is not only a good that good be good; it is also a good that evil be evil. Therefore, and so on.

Note that, as was said above ⁸, the intellect is true when what it conceives of a thing accords with that thing: for then it is adequate to the thing. Now when it conceives of evil that it is evil, then what the intellect conceives of it accords with evil. Therefore in thus understanding it is true. And this is what Saint Thomas says: for it is true that evil is evil—namely because the intellect, in saying that evil befits evil, speaks truly.

III. Fourth. God knows negation. Therefore privation. Therefore evil. — The antecedent is proved: He knows the distinction of things; therefore negation, because negation is contained in the notion of distinction. Hence even the first things, which are distinguished of themselves, mutually include negation, on account of which immediate negative propositions are said to hold among them. — The first consequence is also evident, since privation is a kind of negation. — The second is likewise evident, since evil is a kind of privation.

Note that when it is said that the first things distinguished from one another include mutual negation, this is not to be understood formally, for the negation of quantity does not belong to the essence of substance; but only materially, and fundamentally from its own proper essence. This does not hold in many other cases: for although man is not a stone, the first foundation of this negation is man, not insofar as he is man, but insofar as he is sensible. For this reason, "Man is not a stone" is not an immediate proposition. But the negation of substance from quantity is founded in the proper essence of substance as substance. Therefore, of itself and fundamentally, it includes negation from quantity.

V. Fifth. God knows contraries: since He knows all the species of things, some of which are contraries; and also the differentiae of genera are contraries. Therefore, etc. — The consequence is evident. Because in contraries is included the opposition of privation and habit, as is said in Metaphysics X, text 15.

Sixth. It knows matter. Therefore it knows those things to which matter extends. Therefore it knows privation. Therefore it knows evil. — The first inference is proved: because, since it is a power, it cannot be perfectly known unless it is known to what its power extends. — The second is evident: because its power extends to form and to privation, since that which can be—through the transmutation of matter, namely—can also not be.

Seventh. It knows the order of the universe. Therefore the harms that could arise from certain other things. Therefore evil. — The antecedent is proved. Because, if it knows something other than itself, it knows especially what is best, such as the order of the universe, to which particular goods are ordered as to an end. — But the consequence is evident. Because there are certain things in the universe for removing such harms: as is clear in those things given to animals for defense, such as horns and the like.

Eighth. The knowledge of evils is not blameworthy in itself, that is, by reason of the judgment about evils, but per accidens, by reason of the inclination toward evil that follows from such consideration. But this is not so in God, since He is immutable. Therefore, etc.

It is confirmed by the authority of Wisdom VII, Proverbs xv, the Psalms, and Job xi.

V. As to the second point ⁹, Saint Thomas first explains the difference between our intellect and the divine intellect in the cognition of privation and evil; second, he shows what it is that would impede the divine cognition of evils ¹⁰.

As to the first, he says that our intellect can know privation in two ways. First, insofar as it knows singulars through singular species; and sometimes it is in potency with respect to a species; and thus, just as it knows an act through the act it has in itself, that is, through the intelligible species, so it knows a potency through a potency, namely insofar as it is at times in potency with respect to the intelligible species. And consequently it knows privation, since potency belongs to the ratio of privation. — Second, insofar as from knowledge of act it knows both potency and privation.

The divine intellect, however, does not understand by means of a species that is not itself, but through its own essence. And therefore it does not understand through potency and privation existing in itself; rather, in understanding its own essence, it understands privation. For, understanding itself as the first understood, it understands other things—not only acts, but also potencies and privations.

To this sense, says Saint Thomas, the words of Aristotle, III de Anima, t. 25, are to be understood: namely, that the intellect which is purely in act does not know privation by being in potency to something else, but by understanding itself and being always in act; not, however, that it knows privation in no way at all, as Averroes wrongly interpreted.

2. Concerning the first mode in which our intellect knows privation, namely by knowing the potency and the privation through the potency existing within it, it must be considered that the intellect's knowing potency through potency can be understood in two ways. In one way, so that the potentiality of the intellect, which names the absence of a form together with an aptitude for that form, is the elicitive principle of intellection and of the cognition of potency: just as through act, that is, through the species, it understands what is in act, that is, what signifies some positive nature. And this mode is impossible: for act alone is the principle of action, not potency or privation.

In another way, so that by knowing its own potentiality and privation it may also know an extrinsic potency and privation. But this too we can understand in two ways: namely, either that it knows its own potency and privation before it is informed by the intelligible species to which it is in potency; or after it has been informed by the species. The first way does not seem possible, because, since the intellect understands itself just as it understands other things ¹¹, just as it does not understand other things before it is informed by a species, so neither can it understand itself or its own potentiality before the species. Therefore the second way is to be adopted. On account of which the Philosopher did not say only that one who knows a privation must be in potency, but added "and in that," namely having the species of one of the opposites, as Saint Thomas explains, III de Anima ¹². For if the intellect is to know a privation through the privation existing in itself, it must at some time be in potency with respect to the species of the act; and while it knows that potentiality, it must have in itself the habit of the opposite. For let us imagine that the intellect was at some time in potency with respect to the species of white, and afterwards in act. After it has known, through the cognition of white, reflectively, that it has the species of white and is white intelligibly, it also turns to knowing that it was at some time not white, while it knows that it was deprived of the species and form of white, and hence could not have known white before such a species. And from this it also knows that in esse naturae, that is, what is not white lacks the form of whiteness. And similarly I say of blindness and other privations.

The mind, therefore, of St. Thomas and of Aristotle is that our intellect, by means of the species of a habit existing in itself, cognizes the privation of a form which was once in it and its potentiality toward that species, and also cognizes the privation and potentiality of a thing existing outside the intellect that corresponds to it, by reason of the proportional likeness of the intellect to the thing.

3. Concerning that argument, "Because potency is of the account of privation, it follows that our intellect is in some way able to know privation," note that it does not follow universally that one who knows what is posited in the definition of something also knows the thing defined, except confusedly and indeterminately; for the prior can be known without the posterior being known. In the case at hand, however, since potency is of the account of privation as the subject is of the account of its own proper passion, the intellect cannot completely know itself to be in potency unless it also knows the privation existing in itself, especially since privation immediately follows being in potency: just as man cannot be perfectly known unless his own property, which immediately accompanies him, is known; and one who knows a man can know his passions and properties.

VI. Second, Saint Thomas shows what would impede God's knowledge of evils ¹³. And he says that if God, in knowing himself, did not know particular goods, he would in no way know privation or evil. For, since neither evil nor privation is opposed to him, because he is pure act, if he knew only the good that is himself, he would not know evil: namely, neither because it exists in potency, as was said ¹⁴, nor through knowledge of the opposed good. But since, in knowing himself, he also knows those things in which privations are naturally apt to exist, it is necessary that he know the opposed privations.

From these things it is evident that the divine intellect differs, with respect to the knowledge of evil, from our intellect, because it does not know evil through a potency and privation existing in itself; nor through a proper species of the opposed good perfecting the intellect, as our intellect does; although in this it agrees that it knows evil through the knowledge of the opposed good, just as our intellect does.

Note that when it is said that nothing is opposed to the divine good as a privation, this must be understood according to its proper account. But according to the common account of good, namely insofar as it is good absolutely, evil is indeed opposed to it, as is said in De Veritate, q. II, last article. ¹⁵: for evil and good are opposites.

VII. As to the third ¹⁶, he removes two doubts. For first, someone might say: God knows evils through goods; therefore God's knowledge is discursive. The opposite of this was shown above ¹⁷. — Second: to know something only through another thing known is to know imperfectly. Therefore, if God knows evil only through good, God's knowledge will be imperfect.

To the first it is answered that there is no discursive reasoning. For evils are known through goods, not as conclusions through principles, but as things are known through their definitions. For the good is, as it were, the account by which evil is known, since evil is nothing other than the privation of good.

To the second, he says that knowledge of evil through good is not imperfect: because evil is not naturally able to be known in any other way.

VIII. Concerning the reply to the first objection ¹⁸, a doubt is raised. If good is the intelligible account of evil, and evil is known through good as a thing is known through its definition, then evil does not differ from good: for a thing does not differ from its definition.

Second. It follows that the intellect, in knowing evil, does not form a proper concept of it. But this is false: for concerning blindness it conceives that it is the privation of sight, which concept belongs to blindness alone. And so with the others.

2. To the first of these it is said that it is not the mind of St. Thomas to say that good is the definition of evil, but that it is contained within its definition; for evil is the privation of good, and blindness is the privation of sight. And because, when something is known through that which is of its essence, it is not said to be known by way of discursive reasoning, but through the first operation of the intellect; therefore it was said that that mode of cognition whereby evil is known through good belongs to the mode whereby a thing is known through its definition; that is, it belongs to the first operation of the intellect.

3. To the second, one may first reply that it is indeed true that no quidditative concept is formed of evil, since it signifies no quiddity but rather the negation of quiddity and form. Yet just as the intellect knows evil by the same intelligible species by which it knows good, so too by the same concept by which it knows the quiddity of good it also knows the evil opposed to it. For not everything known must be known through its own proper species or through a proper concept representative of it; it suffices that something be known through a likeness of its opposite. Hence in Truth, q. 2, a. 15, it is said that from the very fact that something is known, its privation is known as well. — Nor does this stand in the way that evil is signified by a proper name, and that a name signifies only by means of a concept. For it may be said that such a name imports no concept of what the thing is, but only of what the name means.

It can be answered secondly that, although the intellect forms a proper concept of evil and expresses it by a proper name, that concept nevertheless does not exclude the concept and intelligible content of good. Indeed, by that very species and likeness of good it forms within itself a concept of evil containing the intelligible content of good: just as when we say that blindness is the privation of sight. Hence the consequence is denied, if it is understood of a proper concept, that is, one suited to it alone. If, however, it is understood of proper in the sense of precision, or exclusion, of the concept of good, it is granted; and its falsity is denied. In proof of this it is said that that concept is proper in the first way, but not in the second, as is evident in itself. Hence also what St. Thomas sometimes says, that evil cannot be conceived under any form, as in Verit., q. iii, a. 4, ad 6, is to be understood of a form excluding the intelligible content of good: not however that no concept is formed of evil. Otherwise it would not be understood as something distinct from good.

4. But according to that reply a doubt arises. For, according to it, it follows that God has His own proper idea of evil. The opposite of this St. Thomas holds wherever he speaks of ideas¹⁹. — The consequence is proved as follows: since an idea, insofar as it names the likeness and the intelligible form by which something is known, corresponds proportionally to a concept of our intellect, it seems that God has proper ideas of all things that are known by us through their own concept.

To this doubt, the inference is denied. For its proof, two things may be said. First, that God has proper ideas of all things that are understood by a proper concept, that is, by a concept excluding every concept of another thing. Now, it is said that evil is not understood by us with a proper concept in this way, as was shown. Therefore what was inferred does not follow.

Second, that God has a proper idea of those things which we understand by a proper concept, if they name some nature; but not if they name a negation. For the idea in the divine mind represents per se those things which participate in the divine essence in some way. But evil does not signify a participation of the divine essence; rather, it signifies more a negation of such participation. Therefore there need not be a proper idea of it, even though we conceive it by some proper concept.