Commentaria in Summam contra Gentiles, Liber I

After Saint Thomas has determined the mode of divine cognition on the side of the medium of knowing, he now determines the mode of cognition on the side of the cognition itself ¹. Now there are four things that Saint Thomas shows concerning this mode: first, he shows that God knows all things at once; second, that in Him there is no habitual knowledge, in the following chapter; third, that His knowledge is not discursive, ch. LVII; fourth, that in it there is neither composition nor division, ch. LVIII.

I. As to the first, he shows that God understands all things at once.

And he argues first ² thus. God knows all things through one species, which is his essence. Therefore he knows all things at once. — The consequence is proved: because whatever many things can be known through one species can be understood at once.

This assumption is declared in our intellect. For the fact that our intellect cannot understand many things at once is because many things cannot at once be one in genus, which would happen if it understood them all at once. For all intelligible species are of one and the same genus, since they share a single mode of being according to intelligible esse. But the intellect is the understood thing in act; and thus, if it understood several things at once, it would be several things of the same genus. — It is nevertheless noted that nothing prevents something from being informed at once by forms of different genera: just as the same body is shaped and colored, although it cannot be informed by several forms of the same genus.

From these things it follows that, where several things are received in whatever way united, they are understood together, just as the parts of a continuum in the continuum, and the subject and predicate in a proposition: namely because then the many are not many, but one. Therefore, where some things are united in one species, those things can be understood together.

II. Concerning this argument, doubt is raised in several ways. For against that assumption, Whatever things can be known by one species can be understood simultaneously, it is argued ³: for it is understood either of confused knowledge or of distinct knowledge. If of confused knowledge, it is not to the point: because God does not know things confusedly, but distinctly. — If of distinct knowledge, then several wholly distinct concepts will be simultaneously in the intellect. Which is no less inconvenient than two species being simultaneously actual in the intellect. The consequence is proved: because to be known properly and distinctly is to be known by a proper and distinct concept.

2. Against the reason why our intellect does not understand several things at once, it is argued ⁴: first, because in the air there is simultaneously the species of white and the species of black according to the same part, if white and black are near each other in the air. Therefore forms of the same genus can be simultaneously in the same subject. — Second. All the forms that are in the angelic intellect are of the same genus: because they regard the same power; for in accordance with what St. Thomas says in the First Part, and elsewhere ⁵, forms that regard the same power are of the same genus. But many of these are simultaneously in act in the angelic intellect: for it simultaneously knows itself through its essence, and other things through a species, and God through the beatific vision by means of the divine essence itself. Therefore an intellect can be in act simultaneously through several species.

3. Against the argument for why all intelligible species are of the same genus, it is argued ⁶: because, if they are of the same genus by the fact that they have the same mode of being according to intelligible esse, then those things which are understood by our intellect through those species will also be of the same genus: for all things agree in the same mode of being according to material esse. Yet this is false, as St. Thomas holds here.

III. For the clarification of these points, it must be considered that, since an operation takes its unity from the unity of the object insofar as it has a likeness in the one operating, and consequently also from the unity of the form which is the principle of the operation, it is not intelligible that there should be one operation while the object and the principle of the operation are not in some way one. Therefore, where the intellect understands many things by a single operation, it is necessary that those things have some unity among themselves, and that the principle of the understanding be in some way one. Since, then, our intellect understands several distinct things—for example, man and horse—when it understands that man is not horse, it forms within itself, from the species of man by which it understood the nature of man and from the species of horse by which it understood the nature of horse, a certain species representative of the difference between man and horse: just as, in a similar case, Saint Thomas says in the First Part, q. XII, a. 9, ad 2, that from the preconceived species of genus and difference it forms the notion of a species. And thus, although man and horse are many things, they nevertheless agree as they are understood under the notion of difference: and so there is some unity on the side of the object. On the side of the principle also there is some unity: because in the intellect there is one species representative of their very difference. And although the species of man and the species of horse are absolutely several in the intellect, yet in this act of understanding they are made one, while each of them concurs as a partial principle in causing the species of difference, in each of which it is in some way contained virtually. And thus further both the species and the objects come together in one concept of the intellect, which is a likeness of the objects as they agree in the nature of difference, and a common effect of the species. And so it must be judged in many other things known by our intellect.

But because it happens not only that many things are understood by some intellect in a single operation of the intellect, but also that many things are understood by diverse acts and diverse intelligible species—as the blessed angel simultaneously knows the divine essence, and himself, and certain of those things whose species he has, by diverse acts and diverse species—we must consider further, from the teaching of Saint Thomas, Verit., q. VIII, a. 14, ad 6, and Prima Pars, q. LVIII, a. 7, ad 2, that where one thing is the reason for another, there they are in a manner one, because from form and matter one thing is made: just as color and light are one visible thing, because light is the reason why color is seen. Therefore, where one thing is the reason for understanding another, there is in some way one intelligible; and several intelligible species, one of which is related to another as form, because it is in some way its reason for representing its object, are in some way one species; and acts of understanding, one of which is ordered to the other, or of which one is the reason for the other, are in a manner one act. Several things can therefore be understood at once by diverse intellections and diverse species when both the species and the intellections have a formal order among themselves, such that one is the reason for the other in understanding. And much more can several things be understood at once when they are understood through one species and by one operation: as happens in the divine cognition by which God understands all things.

What Saint Thomas says, therefore—that the intellect cannot be actualized by several intelligible species at once—is to be understood as meaning that it cannot be actualized by several insofar as they are several. But it can well be actualized by several insofar as they are in some way one species, namely where the ratio of one is the ratio of the other, that is, where the use of one is the reason for using the other: as happens in the knowledge of an angel knowing itself and other things through distinct acts of cognition.

IV. To the first doubt, therefore ⁷ it is said first that knowledge is taken simply and absolutely, in such a way that it abstracts from whether it is confused or distinct.

It is said second, that sometimes those many things are known confusedly, as when the species represents those many things confusedly: which happens to our intellect when it knows the parts through the species of the whole, as they are in the whole. But sometimes they are known distinctly, as when the intelligible species represents distinctly: as is the case in the divine intellect, which, in understanding, represents all things to itself distinctly through its essence; and in the angelic intellect knowing many things through one species, at least many individuals of one species.

And when it is urged that then several wholly distinct concepts would be in the intellect at once, it is said that, speaking of an angel, who alone knows many things distinctly through a single species by forming a concept distinct from itself — for our intellect does not know many things distinctly through one species, because it has limited intelligible species; and the divine intellect does not understand through any concept other than its own essence — while the angel thus understands many things, he does not form several concepts but only one, since he does not understand by composing and dividing, but by a simple intuition. For those several concepts would not be distinguished either by reason of subject, or by reason of principle, or by reason of duration: for they would be received in the same intellect, produced by the same species, and at the same time.

Here it must be noted that, just as the intelligible species of the angelic intellect itself, though one in existence, virtually contains all the species of singulars that are in our imagination; and on this account represents those very singulars just as their particular species would represent them, and indeed in a still more excellent manner: so from that species the angelic intellect forms a simple concept adequate to it, virtually containing the concepts of all things represented by that species, and which is the proper ratio of all such things, and in which all other things actually shine forth. Hence this inference does not hold: The angelic intellect knows these distinctly, Therefore by distinct concepts: but it suffices that it know by one concept what is the ratio of singulars. For to be known distinctly is not to be known by a concept distinct from the concept of another thing according to the thing itself: but by a concept which is its proper ratio, whether it be really or rationally distinct from another, and whether it represent the thing distinctly.

V. To the arguments of the second doubt ⁸ it is answered. To the first, it is said that, according to the mind of St. Thomas in Qq. Verit., q. VIII, a. 14, ad 8, those forms are not in the air in a perfect manner, but only as in a bearer. And thus we also concede that several species can be simultaneously in the intellect in habit, which is an imperfect act. But they cannot be simultaneously in perfect act, namely according to actual consideration, in the way they are in ultimate actuality in the genus of intelligibles: and of that genus we are speaking here.

To the second objection, one can reply in two ways. First, that the mind of St. Thomas is that several species of the same genus, insofar as they are several—that is, as having no unity among themselves—cannot be simultaneously in the same potency; but that those which do have some unity among themselves can be so, and especially when they are related to one another by a certain order of perfection, which is the case here.

Second, that not all those forms are of the same kind, nor do they formally regard the same potency, even though they are in the same intellect: just as, although the same body has whiteness and sweetness, those forms are not said to regard the same potency formally, since whiteness is received in it insofar as it has the nature of the diaphanous, but sweetness insofar as it has the nature of the moist. For the intelligible species regard the intellect as something lacking actual esse for understanding other things, and receptive of the esse of species through information. But the divine essence and the substance of an angel regard it not as actualizable by them through information, but only as actualizable for operating. And thus its potentiality with respect to the intelligible species is of one kind, and another potentiality with respect to the divine essence and the angelic substance. Similarly it would be said of infused and of acquired knowledge in our intellect. For toward one the intellect has a natural potency, toward the other indeed an obediential potency. Therefore they will not be sciences of the same kind, although they are received in the same intellect.

VI. To the third doubt ⁹ the answer is that, if the words of Saint Thomas are carefully considered, it is not his mind that intelligible species are of the same genus because they all have intelligible esse; for in that way God, the intelligences, and the very intelligible species would all be of the same genus, since all have intelligible esse. Rather, they are all of the same genus because they agree in one mode of being of what is intelligible esse. For, since intelligible esse has many modes of being, all the intelligible species of our intellect agree in one mode of being intelligible and have the same intelligible mode of being: for they agree in this mode of being intelligible, that all are brought into act in intelligible esse by the agent intellect through abstraction from phantasms. And consequently they relate formally to the same power of our intellect, namely insofar as it is perfectible by the agent intellect as by its proper agent, through species representative of quiddities only. And likewise all the species of the angelic intellect with which it is informed according to esse have the same intelligible mode of being: because they result from the essence of the angel, and relate to the angelic intellect in the same way; and they are likenesses not only of natures but also of individual principles, inasmuch as the angelic intellect receives them all under one and the same aspect. This, then, is what Saint Thomas intimated by his manner of speaking. For he did not say that those species are of the same character because they all have intelligible esse, but because they have one mode of being according to intelligible esse; that is, they have one mode of being among those which are modes of intelligible esse. And since the argument to the contrary proceeded from a false understanding of the words of Saint Thomas, as though he wished them all to be of the same genus because they have intelligible esse, therefore there is no need to answer otherwise.

VII. Second ¹⁰. All things that are under the divine science must fall under one intention. Therefore God beholds all things at once. — The antecedent is proved: because God intends to see His essence perfectly, which is to see according to the whole of His power, under which all things are comprised. — The consequence is also proved: because things that must fall under one intention must be understood at once, just as one who considers the comparison of two things directs his intention to both and beholds both at once.

For the clarification of this, however, he notes that a cognitive power does not know anything in act unless the intention is present: as is clear in imagination, which sometimes does not imagine phantasms existing in themselves, because the intention is not present. The reason for this is that appetite moves the other powers to act in agents through the will. And thus things that do not fall under one intention are not apprehended simultaneously; but things that do fall under one intention are apprehended so.

Concerning that proposition, "A cognitive power does not know anything in act unless an intention is present," it must be considered what St. Thomas says when we use our powers freely and by choice. On this account he says that the appetite moves the other powers in agents acting through the will. For it is universally true that, when we act freely, the intention of the will applies the power to its operation. But in the motion of the will by which it moves the intellect, since the will is borne toward nothing except what is known, some knowledge, at least confused, precedes the will itself; toward this knowledge the intellect is not moved by the will, but by some higher intellect extrinsic to it, as is said in Prima parte, q. 82, a. 4, ad 3, and in De malo, q. 6, and this is the mind of the Philosopher in the book De bona fortuna ¹¹ Otherwise there would have to be an infinite regress in the mutual motion of intellect and will. Yet nevertheless, because the intellect and the will are powers reflexive upon themselves and upon each other, as is said in De veritate, q. 22 ¹², the will, moved by the intellect thus confusedly apprehending something with a motion of the end, can in turn move the intellect efficiently to a distinct cognition of what was proposed to it confusedly. And thus, although sometimes the senses perceive something suddenly, and the imagination likewise, through some bodily transmutation, operates upon phantasms, as happens in dreams, and the intellect too may be moved by an extrinsic intellect to know something: this is not against the sense of St. Thomas's proposition, because such operations are not in us by choice and freely.

Concerning that proposition, Those things which must fall under one intention must be known together, it should be noted that, just as the intellect cannot be directed toward many things insofar as they are many, but only insofar as they are in some way one; so too an intention can indeed be directed at once toward many things even lacking any order among themselves, yet it cannot be directed toward them except insofar as they agree in some one thing, as is said in the Prima Secundae, q. 12, a. 3, ad 2. On account of this Saint Thomas says that the divine intention is directed toward all things insofar as God intends to know his whole power, under which all things are contained: which is to intend many things insofar as they are in some way one.

VIII. Concerning the proof of the antecedent ¹³ a doubt is raised. For by the same reasoning an angel will be able to know distinctly and simultaneously all things whose natural species he has within himself. Because he intends to know himself perfectly and his own natural properties, which are intelligible species, under which all things intelligible by him are contained. And thus all things intelligible by him fall under one intention.

It is also doubted concerning that proposition, Those things that must fall under one intention must be understood simultaneously ¹⁴. For either we speak of cognition preceding the intention, or of cognition following it. If of the preceding, then it is confused when the intention is directed toward knowing certain things. For the will does not move the intellect toward a cognition it already has before the act of the will, except perhaps with respect to its continuation, but toward one it does not have. Therefore, if the will moves the intellect to a distinct cognition of other things, the cognition that precedes the act of the will will not be distinct, but confused. — If of the cognition that follows the act of the will, the proposition does not seem true. For the will can intend cognitions of different things successively: as when someone proposes to read one book and afterward another, or first to consider the elements and afterward the heavenly bodies.

IX. To the first doubt it is answered that the divine power is related to the things produced in one way, and the intelligible species of the angelic intellects to the intelligible objects known through them in another. For the divine essence and the divine power are the actual likeness of all things, by which all things are present to the divine intellect actually in objective esse, in the way that things are present to our intellect through the species by which we actually understand and through the concept formed by the intellect. Therefore, when God intends to see His essence and His power, which contain all things, He also intends to see all things actually as they are contained in His essence and power. But the species of the angelic intellect are not actual likenesses of their objects, but habitual; hence through them the objects are not posited in actual objective esse. Therefore it is not necessary that an angel, intending to see his natural species, intend to see the objects actually; rather, he intends to see them as they are in him habitually in first act. And thus he sees all things at once in that manner, seeing his species as they are one in his essence—which is to see confusedly, not with proper and distinct cognition, just as when parts are seen in the whole.

But a doubt arises. For although the species is not a likeness of the object in the manner of a concept, it is nevertheless a likeness of the thing. But once the likeness is known, that of which it is the likeness is known. Therefore etc.

It is answered that, once such a likeness of a thing is known as it is the perfection of the knower, the thing itself is known not according to what it is in itself, but according to what it is in the image. And thus it is granted that an angel knows those objects according to the esse they have in those species themselves: but not as they are in themselves.

X. To the second ¹⁵ it is said that the passage is understood of cognition following the intention; as is clear from what he says, since the cognitive power does not know anything in act unless the intention be present, which proposition is not true except of cognition following, and not of that preceding the intention.

But it must be noted that Saint Thomas did not say absolutely and simply, Those things that fall under one intention must be understood simultaneously; rather, he also added a necessity on the part of the intention, saying, Those things that must fall under one and the same intention must be understood simultaneously. For some things fall under one intention of necessity, such that if one is intended, the other must necessarily be intended as well: just as, when medicine is intended under the aspect of being ordered to health, health must necessarily be intended too. But some things fall under one intention not of necessity, but from the freedom of the will: as when someone intends several utilities from one thing, yet could intend one utility and not another. Similarly, therefore, in intended cognitions, of which the proposition of Saint Thomas is understood, some fall of necessity under one intention, because the cognition of one cannot be intended without the cognition of another being intended: and these are the things that have so great a connection with one another that one cannot be known without the other—whether by reason of the objects themselves, as those of which one falls within the account of the other, or on the part of the medium of knowing. But some are such that they do not have such a connection, and one can be intended without the other, even though they fall under one intention: as when someone, intending knowledge of philosophy, at the same time intends to know both the heavens and the elements. Therefore, where certain cognitions fall simultaneously of necessity under one intention, they must also be simultaneously in the intellect: because they fall of necessity under one intention for no other reason than that one cannot be without the other. And thus, since the cognition of all things falls of necessity under one intention of the divine will intending perfectly to see the divine essence, because the divine essence cannot be perfectly seen unless it is seen according to its whole power, under which all things are comprehended; therefore the cognition of the perfect divine essence cannot be intended without the cognition of other things being intended. And consequently God must know all things simultaneously.

To the argument on the opposite side it is said that this is not against the intention of St. Thomas. For although those cognitions are intended together, they do not necessarily fall under one intention.

XI. Thirdly ¹⁶. If God did not know all things simultaneously, He would not understand all things by a single operation. But this is impossible, since His operation is His essence. Therefore, etc. — The antecedent is proved: because for an intellect considering many things successively it is impossible that there be only one operation, since the operations differ according to their objects, and thus the first operation would have to belong to the first object and the second to the second.

XII. But the foundation of this argument seems to be false. For an angel, considering human nature, does not consider Socrates not yet born, because his intuition is not directed toward future things; but once Socrates is born, while the first cognition persists, he considers Socrates, because by one and the same species he knows all the singulars of the species existing at once. Therefore some things can be known successively by one and the same operation. And so we shall say that God has cognition of things successively, just as things have being successively, while nevertheless one and the same operation of the divine intellect remains.

2. To this doubt, if we wish to maintain that several things cannot be known successively by a single operation, it must be said that the argument supposes something false, namely, that Socrates, newly generated, is known by the same act of cognition by which other individuals existing previously were known. For this is false. For just as the species of man was not an actual likeness of Socrates before Socrates existed, so the concept that the intellect formed by means of that species was not a concept of the things proper to Socrates. Therefore, if an angel is to understand Socrates newly, it is necessary that he elicit another act and form another concept.

But if it is urged that operations do not differ except according to the objects to which they are terminated first and per se—the sign of which is that God sees all things by a single operation, because the first and per se object of the divine intellection is one, in which other things are seen; whereas singulars are not first and per se objects of angelic intellection; and thus from their multiplicity and succession there will be no need to multiply intellections—it is answered that if we posit that a newly produced singular is not known by one intellection per se, but by the same intellection together with others, then it cannot be known together with the others except by a new intellection, by which both it and the others are known. And then this cognition differs from that by which the other singulars were known without this one, insofar as the specific nature is known in another way than before: for previously it was not known as limited by these individuating principles, but afterwards it is known as so limited; and thus in some way there are two formal objects of these intellections. For it does not seem conceivable ¹⁷ that something is newly known unless either it itself is known first and per se; or some object is newly known in which it is seen; or an object previously known comes to be known in another way—as when at first some conclusion is known through some principle which was not previously known, this is because the principle is more perfectly known, and thus it has the character of another object in some way, inasmuch as it is presented to the power in a more perfect manner than before.

The proposition of Saint Thomas is therefore taken absolutely, without first specifying the object in itself. For, however succession may occur in the knowledge of certain things, there must be some plurality of objects first and in themselves to which powers are directed; and thus it is necessary that there be several operations—especially where a single operation cannot be intended and perfected, as is the case in God.

3. But if we wish to maintain the other position, namely, that many things can be known successively in one operation, not indeed in themselves, but in something else—which seems to me the more probable view, since an operation has its species and unity from the principal object, and not from the secondary object that is seen in the principal one—then it must be said that it is not the same with the angel's knowledge with respect to singulars as with God's knowledge with respect to things other than himself. For singulars, which are successively known by an angel, are seen not in themselves but in a specific nature, since they are understood through the species of a specific nature. If, however, God were to know many things successively, he would see them in themselves, and not in the divine essence: for the divine essence cannot represent creatures successively, since it is an actual likeness not only of things that exist, but also of things that do not exist.

Hence this proposition, It is impossible for there to be one operation in an intellect considering many things successively, is understood of an intellect considering each of those things in itself, but not of an intellect considering them in something else seen first and principally. — This interpretation is evident from the argument that Saint Thomas adduces: because, I say, operations differ according to their objects. For it is clear that this proposition is true only of objects seen principally, not of objects that are seen in something else.

4. But when it was said in the first reply ¹⁸ that it does not seem imaginable that any individual should come to be known anew unless either it is first known in itself, or something else is newly known in which it is seen, or an object previously known is known in another way — the answer is given that in this case the principal object is known in another way than before, not indeed by another cognition, but by a new disposition of the principal object itself. For just as one and the same intelligible species represented the specific nature without this singular and afterwards represents it together with this singular, not on account of a variation of the intelligible species, but on account of a change in the individual and in some way in the specific nature; so the cognition of such a nature, without any intrinsic variation of itself, was previously terminated at the specific nature without such an individual, but afterwards is terminated at it together with that individual as well. The same account holds for the concept elicited by that species: namely, that without variation of itself it represents the specific nature in different ways in such a case — different, I say, on the side of the thing represented, this difference remaining fixed there.

XIII. Fourth ¹⁹. In God there can be no motion. Therefore there is no succession in His knowledge. — The consequence is proved. Because succession cannot be understood without time, nor time without motion.

Two things must be noted here. First, that according to the doctrine of Saint Thomas ²⁰, besides continuous time there is also discrete time: just as besides continuous motion there is also discrete motion. For discrete motion is composed of diverse instantaneous operations succeeding one another and proceeding from a being in act: and the succession of such operations is called discrete time. Hence Saint Thomas rightly says that no succession can be understood without time, namely continuous or discrete.

The second is that sometimes a single instantaneous operation is called motion, insofar as motion is the act of the perfect: in the way Plato said God moves himself, because he understands himself ²¹. But Saint Thomas does not speak in this way here, when he says it is impossible for any motion to be in God: rather he takes motion as including succession, whatever kind of succession and passage from one thing to another it may be.

Fifth. The divine esse has no before and after. Therefore neither does its consideration. Therefore it knows all things at once. — The consequence is evident, because God's understanding is the very esse itself. — This argument proves that there is no succession on the side of the operation itself.

Sixth. The divine intellect is never in potency. Therefore it understands all things at once. — The consequence is proved: because every intellect that understands one thing after another, while understanding the first in act, understands the second in potency.

The conclusion is also confirmed by the authority of James 1.