Commentaria in Summam contra Gentiles, Liber I

The most learned Saint Thomas resolves the arguments set forth above. But in this matter he does two things: first he shows whence the deception of this opinion arises; second, he replies to the arguments ¹.

I. As to the first, he says there are two things that could have led men into this opinion. The first is indeed custom. For since from the beginning men have been accustomed to hear the name of God and to invoke it, and custom—especially that which is from the beginning ²—has the force of nature, therefore it is firmly held that God is, as if this were naturally and per se known. For those things with which the mind is imbued from childhood are held so firmly as if they were naturally and per se known.

The second is that they did not distinguish between what is known in itself simply, and what is known in itself to us. For that God exists is indeed known in itself simply, because God is his own esse. But as far as we are concerned, it is not known in itself, since we cannot conceive in our mind that very thing which is God. Just as that every whole is greater than its part is known in itself simply, yet to one who could not conceive in his mind the notion of the whole it would not be known in itself, but would indeed be unknown. And for this reason it comes about that our intellect stands toward the most evident things of reality as the eye of an owl toward the sun: namely, because we cannot conceive them as they are.

II. For the declaration of this distinction, it must be noted that a proposition is said to be self-evident because it does not need some other prior and better-known proposition for its manifestation, nor can it be demonstrated by another. On account of which St. Thomas says, I P., q. XVII, a. 3, ad 2, and this is the mind of Aristotle, I Posterior Analytics, ³ and of Boethius, in the book De Hebdomadibus, ⁴ that self-evident principles are those which are known as soon as the terms are known. But because a thing has esse in two ways, namely in one way in itself outside the intellect, and in another way insofar as it is conceived and understood by our intellect, therefore we can speak of a thing in two ways: in one way, according to what belongs to it according to its own nature; in another way, of what belongs to it insofar as it is conceived and understood by us. It is not unfitting, however, that something belong to a thing in some way according to its own nature which does not belong to it according to the manner in which it is conceived by us, and conversely. It can therefore happen that the nature of some subject and predicate be such that one is the same as the other, or that one has an immediate order to the other: and therefore, if each of them were conceived as it is in itself, it would at once appear that the predicate is in the subject. But because the nature of the subject and predicate is not comprehended as it is in itself, but rather is conceived weakly and imperfectly, therefore from that knowledge of the subject and predicate it is not at once known that the predicate is in the subject, but something better known to us and prior is needed for its evidence. Such a proposition is then said to be self-evident simply and according to nature, because it is in the nature of the subject and predicate that, if they were known as they are, the predicate would at once appear to be in the subject, nor would anything better known be needed for obtaining its knowledge: yet it is not self-evident to us, because their nature is not perfectly known, and according to those concepts which we form of the subject and predicate, the connection of the predicate with the subject does not at once appear. On account of which such a proposition is not known once the terms are known, as they are conceived by us. But if some proposition be such that both from the nature of the subject and of the predicate, as they are in themselves, once known, the necessary connection of each appears; and their natures are known to us by their proper and perfect concepts: then such a proposition will be self-evident both according to nature, insofar as their natures are such that, once perfectly inspected, the predicate appears to belong to the subject; and with respect to us, insofar as its evidence appears from the concepts of the terms formed of them by our intellect, but not from some previously known proposition.

Since, therefore, if the divine essence were seen as it is in itself, it would at once appear that existence belongs to it, inasmuch as it is one and the same with that essence itself, we rightly say that God's esse is self-evident simply and by nature. But since that existence necessarily belongs to God, as conceived by us, is not evident except as shown from His effects, because we cannot conceive God as He is in Himself, therefore that proposition is not self-evident with respect to us.

III. But a doubt arises in the doctrine of Saint Thomas as to which propositions are known as soon as their terms are known, which are said to be self-evident to the intellect: for it is of these that we speak, not of those that are known to sense, such as that snow is white. For it seems to some Thomists that only those are of this kind in which the predicate is contained in the definition of the subject; and they think this to be true of Saint Thomas on the basis of certain words of his. — But it seems to others that not only those in which the predicate is contained in the account of the subject are self-evident, but also many others, as appears from those which are adduced by Saint Thomas himself as self-evident ⁵, such as, Every whole is greater than its part, and, If equals are subtracted from equals, what remains is equal, and, Incorporeal things are not in a place, and the like. And they say, in particular, that that proposition is also simply self-evident in which a first passion is predicated of its subject.

We may say, however, that being of the reason and definition of a subject can be taken in two ways: in one way, formally, namely as entering into the subject's essence, as animal is of the reason of man; in another way, virtually and consequently, namely as included virtually in the quiddity of the thing and immediately consequent upon the thing's essence, as if we were to say that it is of the reason of fire to be hot, because heat so follows the essence of fire that fire cannot be without being at once hot. If we take "of the reason of the subject" in the first way, then it does not follow that only that proposition is per se known in which the predicate is of the reason of the subject. Nor does Saint Thomas understand it thus. For although with him every such proposition in which the predicate is of the reason of the subject is per se known, yet conversely not every per se known proposition is of this sort, such that its predicate is of the reason of the subject. For he himself, in I Poster., lect. 36, expounding text 38, places among indemonstrable principles the proposition in which it is signified that a passion belongs to its own and immediate subject, and likewise the one in which the passion is denied of such a subject. This also seems to have been the mind of the Philosopher, in the same place.

But if it is taken in the first or second way under the disjunction, then it is true in his view that every proposition is known of itself and simply such that the predicate is included in the account of the subject. For just as between a subject and its definition nothing intermediate falls in between—on account of which the proposition in which the definition is predicated of the defined is immediate and indemonstrable—so too between a subject and its first passion, as far as the side of the thing is concerned, nothing falls as an intermediary, and the subject has from itself, and not through something else, that such a passion befits it. And on this account the proposition in which such a passion is predicated of the subject is indemonstrable and known of itself, and at once, once the nature of the thing and the definition are known, it appears to him that such a passion belongs to it: just as at once, once the nature and definition of a whole are grasped, it appears that the whole is greater than any of its parts; and, once the nature of fire is known, it is at once seen that heat belongs to it.

2. But here the words of St. Thomas in q. 1 of De Veritate, a. 12, create a difficulty. For there he proves that it cannot be said that the esse of any creature is self-evident and evident in itself, because esse is not perfectly included in the concept of any creature, since the esse of every creature is other than its quiddity. From this the argument runs as follows: No less than esse is the first passion, according to his doctrine, other than quiddity. Therefore, if the esse of a creature is not known in itself because it is other than its quiddity, by the same reasoning neither will that proposition be self-evident in which the passion is predicated of its subject.

I would say, as far as occurs to me for now, that in one way esse is other than quiddity, and in another way a passion is other than its subject. For esse is altogether other than quiddity, and is in no way included in the ratio of a creature—neither, that is, as existing identically with the quiddity essentially, nor as necessarily and immediately accompanying the quiddity: since every creature has esse entirely from without, and consequently the subject does not have from itself that esse befits it, but through another. The first passion, however, although it does not enter into the essence of the thing, nevertheless necessarily and immediately follows upon that essence itself, and is produced from it by a certain natural resultantia. On account of this it belongs to the ratio of subject in the second way spoken of. Therefore that it inheres in its subject is known per se; but not that esse inheres in a creature.

IV. But against two statements made in this determination—namely, that a proposition is self-evident in which the predicate is of the essence of the subject in the manner explained; and that it is one thing for a proposition to be simply self-evident, and another for a proposition to be self-evident to us—Scotus argues. For he holds, I Sentences, d. 2, q. 2, that a proposition is self-evident which has evident truth from its proper terms, which are something of it as they are its terms: and that if a proposition in which a defined term is posited as such—that is, importing a confused concept—is evident from itself, then it is self-evident; but if it is not evident from the terms so taken, although it be evident from the definitive concept, such a proposition is not self-evident.

Against the first statement made by us, therefore, it is argued first from the sayings of Scotus as follows. And it is supposed, from I Posterior Analytics, that what a thing is is the middle of a demonstration. Then thus: In the demonstration set out above, the principle is per se known, but the conclusion is not per se known, but demonstrated. Yet in the premise is placed the definition of the terms, while in the conclusion the defined. Therefore, given that the predicate is in the manner expounded above of the definition of the subject, the proposition will not be per se known, but rather that one in which the predicate is attributed to the definition of the subject. — It is confirmed. Because if such a proposition were per se known, then in a demonstration, in which a proposition is demonstrated through the definition of the subject, beyond the impossibility—namely, that what is indemonstrable would be demonstrated—there would be a begging of the question: because the same would be demonstrated by the same, and the equally known by the equally known.

Second. A proposition is self-evident when it has evident truth from its own terms. But the terms are distinct: the distinct concept of a quiddity, as signified by the definition, and the confused concept of the quiddity, as signified by the name. Therefore a proposition is not self-evident with respect to the quiddity taken confusedly—that is, as it is signified by the name—unless the definition of the name is known.

Third. Then every proposition would be self-evident in the special sciences which the metaphysician could have as self-evident from the definitions of the extremes. But this is not so: because the geometer uses as self-evident propositions only those that possess evident truth from terms known confusedly. Therefore, and so on.

2. Against the second it is argued, because a proposition is said to be self-evident since, as far as the nature of the terms is concerned, it is apt to have evident truth contained in the terms, even if no intellect conceives the terms: for, as far as the terms are concerned, it is self-evident to any intellect, if the terms are conceived. Therefore a proposition self-evident in itself and simply does not differ from one self-evident with respect to us.

It can also be argued against this second point from what Aureol says⁶. The intellect conceiving a proposition that is self-evident either directs its intuition upon the concepts from which knowledge of the proposition arises, or upon others. If upon the same ones, then the proposition will be self-evident to it. If upon others, it is no longer the same proposition: since words alone do not make a proposition, but rather concepts. And thus it is wrongly said that the same proposition is self-evident simply, but not with respect to us.

V. For the solution of these questions, it must be known that when we say a proposition is per se known, meaning one that is known from its own terms and not through another proposition, we call that proposition known from its own terms which is recognized as true from the definitions of its terms. But the definition of a term can be taken in two ways. In one way, for the definition considered on the side of the thing according as it is in itself: and that is the definition by which the very quiddity and essence signified by the name is defined and explicated perfectly and according as it is in itself. In another way, for the definition considered on the side of the thing according as it is in our intellect: and that is the definition which our intellect forms of a thing known by it, as it is known by it, distinguishing it from any other thing, even if at times it represents the nature and essence of the thing imperfectly; as happens in the definitions which our intellect forms of God, and which are signified to us by this name "God."

A proposition is therefore said to be simply self-evident when the predicate belongs to the essence of the subject considered on the side of the thing as it is in itself; and such a proposition, if its terms are known according to that definition, is naturally apt to be evident of itself to the intellect. It is said to be known also with respect to us, however, when that concept, which holds on the side of the thing as it is in itself, is likewise formed by our intellect, and the thing is perfectly known by our intellect as it is in itself.

It must also be noted that the concept and definition, on the side of the thing as it is in itself, considered in itself, can be regarded in two ways: in one way, materially, namely with respect to the thing signified and represented absolutely and in itself; in another way, formally, namely with respect to the thing as it underlies such a definition. In the first way, the definition and the defined are the same: for the definition signifies the same thing as the name of the defined. In the second way, they are distinguished: because the definition represents the thing distinctly, while the name represents it confusedly, as is stated in I Physics, text. 5⁷.

From which it follows that between the defined and the first passion no definition intervenes, if both definition and defined are taken materially: for between the essence of a thing and its immediate passion there is no intermediate thing. But if they are taken formally, between subject and predicate there stands as middle the definition of the subject: first is the thing as confusedly conceived; second, the thing as distinctly conceived; third, the passion following.

It follows, second, that the first and immediate passion cannot be demonstrated through the definition of the subject as through a middle cause, if the definition is taken materially; for the definition taken materially is not a middle between the defined and the passion, but is the same thing as the defined. And this is the sense of the words of St. Thomas when he places among indemonstrable principles the proposition in which a passion is predicated of its proper and immediate subject ⁸. But if the definition is taken formally, then such a passion can be demonstrated through it a priori, as through a cause of cognition; and through a cause in some way in being, in the manner in which the prior reason of a thing is the reason why what is second to it inheres in it.

VI. To the first argument of Scotus against the first statement ⁹ it is answered that the conclusion of such a demonstration is demonstrated, and is not self-evident, if all things are taken formally, and that the quiddity serves as the middle term, as we have shown. But if they are taken materially, then the conclusion is indemonstrable, and the quiddity is not the middle term. Therefore the same proposition is not self-evident in the respect in which it is demonstrated, namely when all things are taken formally; and it is self-evident and indemonstrable when all are taken materially. — To the confirmation it is said that, if all things are taken formally, there is no begging of the question there: because the same thing, distinctly conceived, is formally distinguished from itself as confusedly conceived. But if they are taken materially, then there is a begging of the question, and there are only two terms there: because the middle term and the subject of the conclusion are materially the same. Hence St. Thomas, in the treatise on Fallacies ¹⁰, holds that a begging of the question is committed when it is proved that something belongs to a subject because it belongs to the definition: for, knowing the same thing through the definition and that the defined is signified, if he denies that something belongs to the defined, he will also deny that it belongs to the definition.

To the second it is said that definition and the defined are not other terms if they are taken materially. Hence Saint Thomas, in the Questions on Truth ¹¹ and in other places, proves by this that it belongs to the definition of God to be posited, insofar as it is on the side of God, because the predicate is the same as the subject, since essence and esse are one in God.

To the third, the consequence is denied. For it may stand that in metaphysics there are concepts proper to it which hold on the side of the thing, from which a proposition is rendered self-evident, and yet these are not known in the particular sciences. — Likewise it is false that the geometer uses as self-evident only those propositions which have evident truth from terms known confusedly.

VII. To the argument against the second statement ¹², the consequence is denied. For from the fact that some proposition is said to be self-evident because, as far as the nature of its terms is concerned, it is apt to possess evident truth, and that, of itself, it would be known if its terms were conceived, it does not follow that it is known to us. Rather it follows that, because there is such a proposition which is self-evident by its own nature, whose mutually related concepts on the side of the thing are not had by us, therefore it is known in itself but not to us. And some propositions, as Boethius says in the book De Hebdomadibus ¹³, are self-evident to the wise, who understand the meaning of the terms, but are not self-evident to the common people—for example, that incorporeal things are not in a place.

To Aureol we say that, when we say that the same proposition is known per se simpliciter but is not known per se to us—if we refer this to those who in no way understand the significata of the terms, as when a Greek speaks to a Latin—then the same proposition is taken both materially and formally: because it is in itself known, but by those people the terms are not understood. If, however, it is referred to those who understand the terms in some way, the proposition is said to be the same materially, namely with respect to the utterance and the thing ultimately signified; but not formally with respect to the concept conveyed. Therefore, when an intellect conceives and somehow understands a proposition that is known per se simpliciter but not to itself, it forms other concepts than those by which it is known per se in itself. And so formally it is another proposition from the one that is simply per se known: but materially it is the same, both on the side of the thing signified and on the side of the utterance.

VIII. With these things premised ¹⁴, Saint Thomas answers the first argument made in the preceding chapter in two ways. First, that not all know, even those granting that God is, that God is that than which a greater cannot be thought. Nor can this be understood from the expositions of Damascene.

Second, because, even given that, it is not necessary that something than which a greater cannot be thought exist in the nature of things. For in the same way it is necessary to posit both the thing and the rationale of the name. Nor does it follow except that God is in the understanding.

But against this objection it is said that it is not absurd that, given anything whatever in reality or in the intellect, something greater can be thought, unless for one who grants that there is something than which a greater cannot be thought in the nature of things.

2. Concerning the second reply, in which it is admitted that by the name "God" is signified that than which a greater cannot be thought, yet denied that such a thing must exist in the nature of things, note that regarding that proposition—"In the same way it is necessary to posit both the thing and the meaning of the name"—there is a twofold meaning of a name: namely, formal and objective. The formal meaning is the concept which the intellect forms in itself; the objective meaning is that which, on the side of the thing, corresponds to the concept of the intellect. Now the formal meaning is said to be posited in the thing when there corresponds to it in the thing some objective meaning, which is the thing signified by the name. This proposition, therefore, is to be understood of the formal meaning. For since, as was said ¹⁵, the definition and the defined are materially the same on the side of the thing, if the thing signified by the name is posited in reality, it is necessary that the meaning of the name also be posited in reality—that is, that something existing in reality correspond to the meaning of the name—since the same thing is signified on the side of the thing by the name and by the definition of the name, although what is signified by the name is signified confusedly, while what is signified by the definitive meaning of the name is signified distinctly. For in the same way it is necessary to posit man and rational animal: for if man exists in the nature of things, then rational animal will exist in the nature of things; but if man were only in the intellect, then rational animal would be in the intellect too. Yet from the fact that it is conceived in the mind that this name "God" is uttered, it does not follow that God exists except in the intellect: just as from the fact that it is conceived that this name "void" is uttered, it does not follow that the void exists except in the intellect. Hence, on account of such a conception, it is not necessary that that than which a greater cannot be thought exist except in the intellect.

But when it is urged: "That which exists both in the intellect and in reality is greater than that which exists in the intellect alone. But nothing is greater than God, as is evident from the meaning of the name. Therefore, from the very meaning of the name, it follows that God exists in reality as well, and not only in the intellect" — the reply is given that the minor premise is not true unless it is supposed that God, or something than which a greater cannot be thought, exists in reality. For one who denied that God exists, or that there is anything in reality than which a greater cannot be thought, would say that something can be greater than God, namely that which exists in reality. And when it is proved from the meaning of the name, the reply is given that although by the name "God" is signified that than which a greater cannot be thought, nevertheless that being does not exist in reality.

But it must be noted — since St. Thomas says that it is not inconsistent that something greater can be thought than any given thing, whether in reality or in the intellect, except for one who grants that there is something in the nature of things than which nothing greater can be thought — that if it is not granted that what is signified by this name "God" exists in the nature of things, that which is signified is nothing entitatively and really, although it is something in thought esse: just as is the case with what is signified by the name "void." Therefore it is not inconsistent that something greater be thought than it: because whatever real being, having esse in nature, is thought, that will be worthier and greater: just as a being is nobler than a non-being. Hence that real being, say a man, is nobler as thinkable than God, supposing that what is signified by this name God is nothing in nature but only in thought. — But this is to be understood simply, and with respect to the esse of nature, not however with respect to thought esse. For, although God were not in nature, nevertheless what is signified by this name God is greater than what is signified by this name man, if each is taken only in thought esse: although what is signified by this name man is greater simply and in the esse of nature, just as a being than a non-being, as we said.

IX. To the second, Saint Thomas denies this consequence: God can be thought not to exist, Therefore something greater than God can be thought. For it would be sound if the possibility of thinking him not to exist arose from the imperfection of his esse or from uncertainty, since he would then be an imperfect being; but not if it arises from the weakness of our intellect, which cannot behold him.

It must be noted, however, that the case is not the same for these two propositions: It can be thought that there is something that cannot be thought not to be, and, There can be something in the nature of things that cannot be thought not to be. The first, which the argument assumes, is indeed true: for in thinkable esse it is not unfitting that there be something that cannot be thought not to be. But the second is false: because nothing can be in the nature of things that cannot be thought not to be; since even that God does not exist can fall within human thought, in accordance with that verse of the Psalm ¹⁶: The fool said in his heart: There is no God.

It must be noted further that the following consequence, something greater than God can be thought, is false if we suppose that God exists and that by the name "God" is signified that than which a greater cannot be thought. And because the argument seems to proceed on that supposition, therefore Saint Thomas denies the consequence; but not the falsity of the consequent, as he seems to deny in replying to the first argument, in which it is not supposed—indeed it is denied, given the position of those who hold that God does not exist—that there is anything in reality than which a greater cannot be thought. Hence there is no contradiction when, in his reply to the first argument, he grants that something greater than God can be thought, while here he seems to admit that this is false: for there he answers that, such a thing not being admitted to exist, there is nothing in nature than which a greater cannot be thought; but here he answers on the supposition made by the arguer that something of that kind exists in nature.

X. To the third he responds that to those who see the divine essence it is indeed known that God is per se; yet it is not per se known to us, who arrive at knowledge of him through his effects.

To make this evident, it must first be known that, although a proposition in which the same thing is predicated of itself is simply self-evident, since the predicate not only belongs to the account of the subject but is also wholly identical with the subject, nevertheless with respect to us it may fail to be self-evident, either because we are ignorant of the meanings of the terms, as happens to a Latin speaker with the proposition Anthropos est anthropos, or because we do not know evidently that the predicate is identical with the subject, and this is the case with the proposition Deus est. For since we do not see the divine essence as it is in itself, neither can we comprehend its esse per se, so as to see from the terms, as they are conceived by us, that esse is not distinct from its essence; rather, we arrive at that knowledge through its effects. But for the blessed this is most evident, because they behold the divine essence itself.

2. To the fourth he says that man desires God naturally insofar as he desires beatitude, which is a certain likeness of the divine goodness. Therefore it is not necessary that God himself, considered in himself, be naturally known to man, but only his likeness.

To make this evident, it must be known that man is said to desire beatitude naturally, which is a certain likeness of God, and thus to know God in His likeness—not because he desires beatitude under this particular aspect, namely the vision of the divine essence, for neither is it known naturally nor desired naturally, speaking absolutely; but because he desires beatitude in common, since each person wills to be blessed. And in whatever the account of beatitude is placed, that is a certain likeness of divine goodness.

3. To the fifth he says that all things are indeed known to God, not as first known, but because through His influence all knowledge is caused in us.