Commentaria in Summam contra Gentiles, Liber I

After Saint Thomas has determined the secondary general object of divine cognition in itself, he now determines it with respect to the mode of cognition ¹. Concerning this, however, he does two things: first, he treats of the mode that holds on the side of the object; second, of that which holds on the side of the knower, in the following chapter.

I. As to the first, he proposes this conclusion: God knows things other than himself insofar as they are distinct from one another.

He, however, declares it from the opinion of others. For there was the opinion of certain thinkers that God has knowledge of other things only in a universal way, inasmuch as he knows them as beings, because he apprehends the nature of being through his knowledge of himself. This opinion will be treated at the end of this chapter ². But we say that God knows other things not only with respect to the common predicates in which they agree, but also as they are distinct from one another, that is, with respect to their proper features by which one thing is distinguished from another. And this is to know things according to their proper rationes.

The conclusion is proved, however, on the supposition that God is the cause of every being, whether mediately or immediately, which will be shown more fully below. And first thus: God knows himself and all the intermediate causes that are between him and any given thing. Therefore he has proper knowledge of things insofar as they are distinct from one another. The antecedent is proved. For that God knows himself perfectly was shown above. That he also knows the other intermediate causes is shown because, having known himself, he knows what is immediately from him; and this known, he again knows what is mediately from that; and so on down to the last effect, since all secondary causes proceed from him. The consequence is also proved. Because, once the cause is known, its effect is known. And thus, God and all the intermediate causes being known, whatever is in a thing is known. But this is to know both the common features and the proper features of a thing, and thus to have proper, complete, and distinct knowledge of it.

Concerning this proposition, When the cause is known, the effect is known, it must be noted that it holds true under two conditions understood, speaking of a cause per se: namely, first, that the cause be known with respect to that by which it is the cause of the effect; second, that it be known formally insofar as it is a cause. On account of a failure of the first condition, if fire is known only with respect to its dryness, the hot thing produced by it is not thereby known under the aspect of heat: because it is not known with respect to that by which fire is the cause of heat. On account of a failure of the second condition, when fire is known with respect to its heat, which is the cause of this particular heat, if I do not know it as the cause of this heat, I do not for that reason know this heat, that is, from knowledge of such a cause. But since God knows all causes of things with respect to that by which they are causes, and knows them themselves to be the causes of such things, therefore from his knowledge of all causes he distinctly knows all things.

II. Second. God is the cause of things through intellect: because each thing acts insofar as it is in act; and God's esse is His understanding. Therefore He knows things distinctly. — The consequence is proved. Because every agent acting through intellect has cognition of the thing it produces according to the proper rationale of the thing made: since the cognition of the maker determines the form for the thing made.

2. But this argument seems to fail in two ways. First, because if it follows from the fact that God's esse is His own understanding that God acts through intellect, then, wherever the esse of a cause will not be its own understanding, that cause will not act through intellect: for just as affirmation is the cause of affirmation, so negation is the cause of negation ³. And thus man would in no way act through intellect.

Second, because those who hold the first opinion could say that God is the cause of all things with respect to esse alone. Therefore it suffices that He have knowledge of things only insofar as they are beings ⁴.

3. To the first it is replied that that is not the adequate reason why something acts through intellect, namely, that its esse is to understand. Therefore it is not necessary that the negation of that cause be the reason why something does not act through intellect; for Aristotle's proposition is understood only of an adequate and proper cause. But there is a reason concluding on account of matter in God. For if each thing acts insofar as it actually exists, because existing is a condition necessarily required in order that something act, it follows, since God's existing is His understanding, that God acts insofar as He understands, so that understanding is a condition necessarily required in order that He act.

4. But then a greater difficulty arises. For understanding is taken either formally, insofar as it is understanding, or materially, with respect to that entity which is understanding. If formally, then the false is subsumed, namely that God's esse is formally understanding. Indeed, they are formally distinct, and are understood by us under different concepts. — If materially, it will no more follow that God acts insofar as he understands, or through the intellect, than that he acts insofar as he is just, or through justice: for just as understanding is materially the same in God as esse, so too is justice.

It is answered that understanding is taken formally on the side of the thing, and not merely materially. For understanding has this proper to it in God, that it is formally identical with the divine esse: because each of them signifies ultimate actuality. For esse is the ultimate actuality of God insofar as He is in the genus of beings; but understanding is His ultimate actuality insofar as He is in the genus of intelligibles. Now the genus of being in God and the genus of the intelligible are formally identical, since God is both subsistent immaterial esse and subsistent understanding. But this does not belong to the other things that are in God, since they do not signify ultimate actuality, even though they too are subsistent. Hence they are not formally identical with esse insofar as it is esse, as understanding is. And for this reason it does not follow that, if He acts insofar as He is in act, He acts insofar as He is just.

It can be answered secondly that the esse of God, by which He is understood to subsist, can be considered in two ways: in one way, absolutely, as the actuality of being; in another way, as the formal containing principle of things producible by God. If it is taken in the first way, it is thus formally distinct from understanding. But if it is taken in the second way, it is thus formally understanding: because in God things are contained virtually as in an agent through knowledge, not as in an agent through nature. Now in such an agent the principle of acting is knowledge, at least habitual. Therefore, since in God there is no habitual knowledge but only actual knowledge ⁵, the principle of acting in God is the very act of understanding. Hence Saint Thomas takes esse in this second way, not in the first: for by esse taken in this way God is in act with respect to the things producible by Him.

5. To the second ⁶ it is said that the argument presupposes God to be the cause of things not only insofar as they are beings, but also insofar as they are such beings. This will be proved below ⁷.

III. Third. God, by causing things, understands the distinction of all things. Therefore He knows things as distinct. — The consequence is evident. For unless He knew them as distinct, He would not intend their distinction through His knowledge. — The antecedent, however, is proved as follows. Either the distinction of things is from chance, or from an agent acting by the necessity of nature, or from some particular intelligent cause, or from the intention of the first cause, which is God. Not the first: because it has a certain order. Not the second: because nature is determined to one thing, and consequently an agent acting by the necessity of nature cannot intend many things insofar as they are distinct; hence Anaxagoras said that intellect is the principle of distinction, as though it were proper to intellect to consider the distinction of things. Not the third: because every cause of this kind belongs to the number of distinct caused things. Therefore the fourth. Which was the intended conclusion.

But a doubt arises concerning what is said: an agent acting by nature cannot intend many things insofar as they are distinct. For the intention of the animal generating another animal seems to be directed toward the many parts of the animal, since it produces them in an ordered way, and of diverse complexions. — If it is said that it does not intend those parts except insofar as from them one animal is constituted, and not insofar as they are distinct: then in the same way it will be said that an agent acting by intellect does not intend many things insofar as they are distinct, but rather insofar as they come together in one certain order of the universe.

It is answered that an agent acting by necessity of nature intends one thing simpliciter with respect to the first intention of nature; but many and distinct things only secondarily, insofar as those are necessary for the unity of that which it principally intends; so that in no way does it intend them as they are distinct, although it intends distinct things with a secondary intention. An agent, however, acting through intellect, although it can intend many things insofar as they come together into one order, can nevertheless also intend many things as they are distinct, intending their distinction and each one according to its proper ratio—insofar as from the distinction of some things as they are distinct one order results, or even without order. Therefore the difference between nature and intellect is not as if intellect could intend many things while nature could not at all: rather, because if nature should intend many things in any way—things that have the character of parts—it does not intend them as many and distinct, as if intending their distinction per se; whereas intellect can intend many things, each of which is perfect, as they are distinct, intending their distinction and plurality. But deception occurs here because it is thought that to intend many things is the same as to intend plurality, or many things as they are many. To show that this is not true, Saint Thomas said not absolutely that a natural agent does not intend many things, but that it does not intend many things as they are distinct.

IV. Fourth. God knows whatever He knows most perfectly. Therefore He knows things by their proper cognition, not merely universally. — The antecedent is evident, because in Him is every perfection, as in the simply perfect. — The consequence is proved as follows: what is known only in common is known imperfectly, and more in potency than in act, since those things that are chief in it are unknown, namely the ultimate perfections by which its proper esse is perfected.

2. Concerning this proposition, That which is known only in common is known imperfectly and in potency, it must be noted that in that cognition by which something is known in common, two things are known: namely, the universal itself in which the other is known; and that to which such a universal belongs, insofar as it is contained in that universal. If the universal itself is considered in itself, then it is not unfitting for it to be known actually and perfectly—that is, insofar as it is a certain essential whole. For it can be known distinctly with respect to all the things that belong to its definition; just as animal is known perfectly insofar as it is a certain essential whole, when it is known to be an animate sensible substance, and all the properties proper to it are known insofar as it is animal.

3. But if the thing that is contained and known in common is considered, we can understand the thing in common in two ways. In one way, by knowing the common itself through the mode of universal abstraction from the particular, that is, not considering it as it is in the particular, as when animal is considered absolutely: for since man is contained in animal, therefore, while animal is known, man is said to be known in some way, as something contained potentially in animal. In another way, by knowing it through its application to the particular: as when it is known that man is an animal.

In both ways the thing is known in an imperfect manner: because it is not known with respect to those features by which it is distinguished from other things and is constituted in its proper esse.

It is likewise known in potency in both ways, but nevertheless in different ways. For in the first way it is known simply in potency, just as it is contained only potentialiter in that common nature itself: for when I know animal abstractly, I am said to know man in potency as well, because man is contained in animal in potency; just as one who knew prime matter absolutely, or only universally by comparison to form, would know the particular forms in potency, just as they are contained in that matter in potency. — But in the second way it is known in potency only secundum quid. For when I know that man is an animal, I do indeed know man actualiter, since the act of intellect terminates upon him: yet he can be said to be known in potency, insofar as he is known not with respect to the difference by which he is constituted in act within the species, but with respect to the predicate in which he is contained in potency together with others.

Since, therefore, the aforementioned opinion held that God knows beings in the first common way, when it said that He knows them insofar as He knows the nature of esse absolutely, Saint Thomas simply said that by such knowledge the thing is known more in potency than in act.

V. Fifth. God knows the nature of being. Therefore He knows multitude. Therefore He understands things as they are distinct from one another. — The second consequence is evident, because multitude cannot be understood without distinction. — The first is also evident, because one and many are accidents of being insofar as it is being, as is said in Book IV of the Metaphysics, texts 3 and 4. But whoever knows any nature knows per se the accidents of that nature.

2. But this argument seems not to conclude. For one who knows a nature does not know the accidents of that nature except insofar as they belong to that nature, and not as they belong to other things: just as one who knows man knows risibility as belonging to man, but not as it is in this particular man or in that one. Therefore, if one and many are proper accidents of being insofar as it is being, it follows that one who knows being knows multiplicity as common being entails it, but not as it belongs to these or those beings. Hence it does not follow from the knowledge of this accident insofar as it accompanies being in common, that things are known insofar as they are distinct: just as from the fact that risibility is known to follow human nature, and thus that man is risible, it does not follow that I know Socrates or Plato to be risible; for it may stand that I know the universal nature, and yet do not consider the particulars contained under that nature.

3. It is answered that, since being does not signify one nature simply, as we showed above ⁸, but many natures insofar as they are one by proportion, the passions of being are not taken as consequents of a single nature of being found in all things, but as consequents of the natures signified by the name "being," which nevertheless are one by proportion. And because things that are one by proportion cannot be perfectly known unless the proportion of each is known—just as six and four cannot be known to be proportional in comparison to three and two unless it is known that six is double three and four double two, since a likeness cannot be known unless the extremes of the likeness are known—therefore the nature of being cannot be perfectly known unless the natures having proportion to one another in order to esse are known; nor can the nature of a passion of being be perfectly known unless the natures contained under being, to which that passion proportionately belongs, are known.

A multitude, however, cannot be known singularly unless the things that are many and distinct are known. For multitude follows upon being, not in respect of one common nature of being, but in respect of certain things contained under being, in which multitude is preserved either in the manner of an accident or in the manner of a substance. And therefore, if multitude is to be known as something existing in many and distinct things, it is necessary that the things which are many be known under a certain distinction of one from another. The same holds for the odd with respect to number. For in order that this property of number which we call "odd" be known, it does not suffice to know the nature of number in common, because this property does not follow upon number except by reason of certain of its species, in which it is found; rather, that species of number must be known upon which this property follows—although it also follows upon number absolutely, under a disjunction with the even.

To this objection, then, it is said that it is not the same with risibility in respect of man as with multitude in respect of being. For risibility follows upon the nature of man absolutely, which is simply one; but multitude follows upon being by reason of certain things contained under being.

VI. Sixth. God, in knowing himself, knows the universal nature of being: and perfectly, because every imperfection is removed from it. Therefore he knows all the grades of beings. And thus he has a proper knowledge of things. — The consequence is proved. Because one who knows some universal nature perfectly knows the mode in which that nature can be had. Now, from the diverse modes of existing are constituted the diverse grades of beings.

2. Concerning the proof of the consequence, a doubt arises. For the metaphysician knows perfectly the universal nature of being, since his formal subject is being inasmuch as it is being. And yet he does not know every mode in which the nature of being can be had, since he does not know things except in the universal, as is stated in I Metaphysics⁹ Therefore it does not follow that one who knows some universal nature perfectly must know every mode in which it can be had.

3. For the clarification of this, it must be considered that any universal nature can be considered in two ways: in one way, insofar as it is a certain essential whole, namely as having a nature and essence distinct from other universal natures; in another way, insofar as it is a whole universal, namely as containing many things within itself potentially and as common to many. If it is considered in the first way, then for its perfect cognition it is not required that every mode be known in which it can be had by inferiors insofar as it is a whole universal; rather, it suffices that all things which belong to its ratio be known, and all things which of themselves follow upon its proper ratio. For animal is thus perfectly known when it is known to be an animate sensible substance, and when all things are known that befit it insofar as it is animal. — But if it is considered in the second way, then for its perfect cognition it is required that all its differences be known by which it is contracted to its inferiors; for those inferiors are its parts insofar as it is a universal, just as the things that fall within its definition are its parts insofar as it is an essential whole. — The proposition of St. Thomas, therefore, is understood concerning the perfect cognition of a universal in both ways at once: but not concerning its cognition in the first way only.

But as for the objection from the metaphysician, it is said that the metaphysician does not know being perfectly in both ways, but only in the first way: for this suffices for a perfect knowledge of being insofar as it is his subject. But God knows it perfectly in both ways. Therefore the objection is not against what is intended.

VII. Seventh. God knows Himself perfectly. Therefore He has proper knowledge of all things. — The consequence is proved. Because one who knows something perfectly knows all things that are in it. But in God are all things, according to active power, with respect to their proper forms.

Note that this argument differs from the first, although it may seem the same as it. In the first, indeed, the order of all causes to their effect was considered insofar as from knowledge of the causes one arrives at knowledge of the effects. Here, however, the existence of the effects in God himself is considered formally, insofar as the particular forms of all beings are contained in the active power of God—that is, insofar as in God there is the power for the particular forms of all things, as in the first cause of all.

Eighth. God knows in how many ways something can be like him. Therefore he knows things according to their proper forms. — The consequence is evident. For from this arise the diversities of forms, because things imitate the divine essence in diverse ways. Hence the Philosopher too calls form a certain divine thing. — The antecedent, however, is proved. Because whoever knows a nature knows whether and how it is communicable. Now the divine nature is communicable by way of likeness.

Note that the universal nature is communicable in one way, and the divine nature in another. For the universal nature is communicated because it belongs to many according to the same ratio, yet it has diverse esse in them. The divine nature, however, is not communicated to creatures in this way, but because all things participate in some imperfect likeness of it: for every perfection, as was shown above¹⁰, is a certain participated likeness of divine esse. And this is what St. Thomas intends when he says that the divine nature is communicable by likeness: namely, that, being one, it terminates the likeness of creatures to itself; or, which is the same thing, that it is that to which every perfection of a creature is assimilated.

Ninth. Other knowers know things as they are distinct. Therefore God also. — The consequence is proved. For otherwise God would be most foolish: as the Philosopher argues, I de Anima, text. 80¹¹, and III Metaphysics, text. 15, against those who say that God does not know the dispute, which all men know.

It is confirmed by the authority of Gen. 1, "And God saw all things that he had made," and of Heb. 4, "No creature is invisible to him."

VIII. As to the opinion attacked here¹², it must be known that Saint Thomas attributes it to the Commentator in I Sent., d. xxxv, a. 3; and it is found in XII Metaphys., comm. 51, at the end. — Yet the opposite seems to be intended also in XII Metaph., comm. 52; and II Physic., comm. 75; and II de Anima, comm. 34, where he holds that the first cause has care for lower things. This is found even more clearly in X Ethic., cap. X¹³, where he says that God visits the wise man as a friend does a friend. Nor does it avail to say that this care signifies causality only by way of an end, and not knowledge of things. First, because care names no causality except together with cognition. Second, because to be concerned about a thing is not to be its end, but rather to direct it toward a known end. On account of which he says in his commentary on II Phys.¹⁴ that, if the Divine does not admit that nature acts for an end, it cannot account for care about things: namely, because it follows that God does not direct natural things to an end, which is to have care for them.

It will therefore be more fitting to say either that he contradicts himself—which I do not think should be attributed to so great a man, especially since he states the opposing positions in two immediately consecutive commentaries—or that he understood this providence to concern things only insofar as they are beings, just as that knowledge knows them only insofar as they are beings: so that, just as it knows the nature of being, so it disposes things as the nature of being requires, without descending to this or that particular being; but through particular agents things are disposed to be this or that being. And thus his providence extends to these things insofar as he intends the nature of being, which is preserved in them. — As for what he says in Ethics X, the very order of things shows that he speaks on a supposition: namely, if God does indeed care for singulars as singulars.

But if anyone wished to maintain that this is the mind of the Commentator, on account of the authorities adduced, that God has a proper and distinct knowledge of things, he could first say that in his commentary on Metaphysics XII, lecture 51, Averroes understood that God knows beings insofar as they are beings by knowing himself, since he knows other things distinctly only by knowing himself, who is subsistent esse, in which all beings are contained eminently. — Second, one could say that St. Thomas attributes that opinion to Averroes insofar as his words sound in that passage. For there he does not otherwise explain his intention, but from his very words it is gathered that he knows beings only in common, namely insofar as they are beings. But St. Thomas does not care what he himself understood.

How much falsehood this opinion contains is clear from the arguments adduced.