Summa Theologica

Objection 1: It seems that the knowledge of God is variable. For knowledge is related to what is knowable. But whatever imports relation to the creature is applied to God from time, and varies according to the variation of creatures. Therefore the knowledge of God is variable according to the variation of creatures.

Objection 2: Further, whatever God can make, He can know. But God can make more than He does. Therefore He can know more than He knows. Thus His knowledge can vary according to increase and diminution.

Objection 3: Further, God knew that Christ would be born. But He does not know now that Christ will be born; because Christ is not to be born in the future. Therefore God does not know everything He once knew; and thus the knowledge of God is variable.

On the contrary, It is said, that in God "there is no change nor shadow of alteration" (James 1:17).

I answer that, Since the knowledge of God is His substance, as is clear from the foregoing(A[4]), just as His substance is altogether immutable, as shown above (Q[9], A[1]), so His knowledge likewise must be altogether invariable.

Reply to Objection 1: "Lord", "Creator" and the like, import relations to creatures in so far as they are in themselves. But the knowledge of God imports relation to creatures in so far as they are in God; because everything is actually understood according as it is in the one who understands. Now created things are in God in an invariable manner; while they exist variably in themselves. We may also say that "Lord", "Creator" and the like, import the relations consequent upon the acts which are understood as terminating in the creatures themselves, as they are in themselves; and thus these relations are attributed to God variously, according to the variation of creatures. But "knowledge" and "love," and the like, import relations consequent upon the acts which are understood to be in God; and therefore these are predicated of God in an invariable manner.

Reply to Objection 2: God knows also what He can make, and does not make. Hence from the fact that He can make more than He makes, it does not follow that He can know more than He knows, unless this be referred to the knowledge of vision, according to which He is said to know those things which are in act in some period of time. But from the fact that He knows some things might be which are not, or that some things might not be which are, it does not follow that His knowledge is variable, but rather that He knows the variability of things. If, however, anything existed which God did not previously know, and afterwards knew, then His knowledge would be variable. But this could not be; for whatever is, or can be in any period of time, is known by God in His eternity. Therefore from the fact that a thing exists in some period of time, it follows that it is known by God from eternity. Therefore it cannot be granted that God can know more than He knows; because such a proposition implies that first of all He did not know, and then afterwards knew.

Reply to Objection 3: The ancient Nominalists said that it was the same thing to say "Christ is born" and "will be born" and "was born"; because the same thing is signified by these three—viz. the nativity of Christ. Therefore it follows, they said, that whatever God knew, He knows; because now He knows that Christ is born, which means the same thing as that Christ will be born. This opinion, however, is false; both because the diversity in the parts of a sentence causes a diversity of enunciations; and because it would follow that a proposition which is true once would be always true; which is contrary to what the Philosopher lays down (Categor. iii) when he says that this sentence, "Socrates sits," is true when he is sitting, and false when he rises up. Therefore, it must be conceded that this proposition is not true, "Whatever God knew He knows," if referred to enunciable propositions. But because of this, it does not follow that the knowledge of God is variable. For as it is without variation in the divine knowledge that God knows one and the same thing sometime to be, and sometime not to be, so it is without variation in the divine knowledge that God knows an enunciable proposition is sometime true, and sometime false. The knowledge of God, however, would be variable if He knew enunciable things by way of enunciation, by composition and division, as occurs in our intellect. Hence our knowledge varies either as regards truth and falsity, for example, if when either as regards truth and falsity, for example, if when a thing suffers change we retained the same opinion about it; or as regards diverse opinions, as if we first thought that anyone was sitting, and afterwards thought that he was not sitting; neither of which can be in God.

Objection 1: It seems that God has not a speculative knowledge of things. For the knowledge of God is the cause of things, as shown above(A[8]). But speculative knowledge is not the cause of the things known. Therefore the knowledge of God is not speculative.

Objection 2: Further, speculative knowledge comes by abstraction from things; which does not belong to the divine knowledge. Therefore the knowledge of God is not speculative.

On the contrary, Whatever is the more excellent must be attributed to God. But speculative knowledge is more excellent than practical knowledge, as the Philosopher says in the beginning of Metaphysics. Therefore God has a speculative knowledge of things.

I answer that, Some knowledge is speculative only; some is practical only; and some is partly speculative and partly practical. In proof whereof it must be observed that knowledge can be called speculative in three ways: first, on the part of the things known, which are not operable by the knower; such is the knowledge of man about natural or divine thing. Secondly, as regards the manner of knowing—as, for instance, if a builder consider a house by defining and dividing, and considering what belongs to it in general: for this is to consider operable things in a speculative manner, and not as practically operable; for operable means the application of form to matter, and not the resolution of the composite into its universal formal principles. Thirdly, as regards the end; "for the practical intellect differs in its end from the speculative," as the Philosopher says (De Anima iii). For the practical intellect is ordered to the end of the operation; whereas the end of the speculative intellect is the consideration of truth. Hence if a builder should consider how a house can be made, not ordering this to the end of operation, but only to know (how to do it), this would be only a speculative considerations as regards the end, although it concerns an operable thing. Therefore knowledge which is speculative by reason of the thing itself known, is merely speculative. But that which is speculative either in its mode or as to its end is partly speculative and partly practical: and when it is ordained to an operative end it is simply practical.

In accordance with this, therefore, it must be said that God has of Himself a speculative knowledge only; for He Himself is not operable. But of all other things He has both speculative and practical knowledge. He has speculative knowledge as regards the mode; for whatever we know speculatively in things by defining and dividing, God knows all this much more perfectly.

Now of things which He can make, but does not make at any time, He has not a practical knowledge, according as knowledge is called practical from the end. But He has a practical knowledge of what He makes in some period of time. And, as regards evil things, although they are not operable by Him, yet they fall under His practical knowledge, like good things, inasmuch as He permits, or impedes, or directs them; as also sicknesses fall under the practical knowledge of the physician, inasmuch as he cures them by his art.

Reply to Objection 1: The knowledge of God is the cause, not indeed of Himself, but of other things. He is actually the cause of some, that is, of things that come to be in some period of time; and He is virtually the cause of others, that is, of things which He can make, and which nevertheless are never made.

Reply to Objection 2: The fact that knowledge is derived from things known does not essentially belong to speculative knowledge, but only accidentally in so far as it is human.

In answer to what is objected on the contrary, we must say that perfect knowledge of operable things is obtainable only if they are known in so far as they are operable. Therefore, since the knowledge of God is in every way perfect, He must know what is operable by Him, formally as such, and not only in so far as they are speculative. Nevertheless this does not impair the nobility of His speculative knowledge, forasmuch as He sees all things other than Himself in Himself, and He knows Himself speculatively; and so in the speculative knowledge of Himself, he possesses both speculative and practical knowledge of all other things.

After considering the knowledge of God, it remains to consider ideas. And about this there are three points of inquiry:

(1) Whether there are ideas?

(2) Whether they are many, or one only?

(3) Whether there are ideas of all things known by God?

Objection 1: It seems that there are no ideas. For Dionysius says (Div. Nom. vii), that God does not know things by ideas. But ideas are for nothing else except that things may be known through them. Therefore there are no ideas.

Objection 2: Further, God knows all things in Himself, as has been already said (Q[14], A[5]). But He does not know Himself through an idea; neither therefore other things.

Objection 3: Further, an idea is considered to be the principle of knowledge and action. But the divine essence is a sufficient principle of knowing and effecting all things. It is not therefore necessary to suppose ideas.

On the contrary, Augustine says (Octog. Tri. Quaest. qu. xlvi),"Such is the power inherent in ideas, that no one can be wise unless they are understood."

I answer that, It is necessary to suppose ideas in the divine mind. For the Greek word {Idea} is in Latin "forma." Hence by ideas are understood the forms of things, existing apart from the things themselves. Now the form of anything existing apart from the thing itself can be for one of two ends: either to be the type of that of which it is called the form, or to be the principle of the knowledge of that thing, inasmuch as the forms of things knowable are said to be in him who knows them. In either case we must suppose ideas, as is clear for the following reason:

In all things not generated by chance, the form must be the end of any generation whatsoever. But an agent does not act on account of the form, except in so far as the likeness of the form is in the agent, as may happen in two ways. For in some agents the form of the thing to be made pre-exists according to its natural being, as in those that act by their nature; as a man generates a man, or fire generates fire. Whereas in other agents (the form of the thing to be made pre-exists) according to intelligible being, as in those that act by the intellect; and thus the likeness of a house pre-exists in the mind of the builder. And this may be called the idea of the house, since the builder intends to build his house like to the form conceived in his mind. As then the world was not made by chance, but by God acting by His intellect, as will appear later (Q[46], A[1]), there must exist in the divine mind a form to the likeness of which the world was made. And in this the notion of an idea consists.

Reply to Objection 1: God does not understand things according to an idea existing outside Himself. Thus Aristotle (Metaph. ix) rejects the opinion of Plato, who held that ideas existed of themselves, and not in the intellect.

Reply to Objection 2: Although God knows Himself and all else by His own essence, yet His essence is the operative principle of all things, except of Himself. It has therefore the nature of an idea with respect to other things; though not with respect to Himself.

Reply to Objection 3: God is the similitude of all things according to His essence; therefore an idea in God is identical with His essence.

Objection 1: It seems that ideas are not many. For an idea in God is His essence. But God's essence is one only. Therefore there is only one idea.

Objection 2: Further, as the idea is the principle of knowing and operating, so are art and wisdom. But in God there are not several arts or wisdoms. Therefore in Him there is no plurality of ideas.

Objection 3: Further, if it be said that ideas are multiplied according to their relations to different creatures, it may be argued on the contrary that the plurality of ideas is eternal. If, then, ideas are many, but creatures temporal, then the temporal must be the cause of the eternal.

Objection 4: Further, these relations are either real in creatures only, or in God also. If in creatures only, since creatures are not from eternity, the plurality of ideas cannot be from eternity, if ideas are multiplied only according to these relations. But if they are real in God, it follows that there is a real plurality in God other than the plurality of Persons: and this is against the teaching of Damascene (De Fide Orth. i, 10), who says, in God all things are one, except "ingenerability, generation, and procession." Ideas therefore are not many.

On the contrary, Augustine says (Octog. Tri. Quaest. qu. xlvi), "Ideas are certain principal forms, or permanent and immutable types of things, they themselves not being formed. Thus they are eternal, and existing always in the same manner, as being contained in the divine intelligence. Whilst, however, they themselves neither come into being nor decay, yet we say that in accordance with them everything is formed that can rise or decay, and all that actually does so."

I answer that, It must necessarily be held that ideas are many. In proof of which it is to be considered that in every effect the ultimate end is the proper intention of the principal agent, as the order of an army (is the proper intention) of the general. Now the highest good existing in things is the good of the order of the universe, as the Philosopher clearly teaches in Metaph. xii. Therefore the order of the universe is properly intended by God, and is not the accidental result of a succession of agents, as has been supposed by those who have taught that God created only the first creature, and that this creature created the second creature, and so on, until this great multitude of beings was produced. According to this opinion God would have the idea of the first created thing alone; whereas, if the order itself of the universe was created by Him immediately, and intended by Him, He must have the idea of the order of the universe. Now there cannot be an idea of any whole, unless particular ideas are had of those parts of which the whole is made; just as a builder cannot conceive the idea of a house unless he has the idea of each of its parts. So, then, it must needs be that in the divine mind there are the proper ideas of all things. Hence Augustine says (Octog. Tri. Quaest. qu. xlvi), "that each thing was created by God according to the idea proper to it," from which it follows that in the divine mind ideas are many. Now it can easily be seen how this is not repugnant to the simplicity of God, if we consider that the idea of a work is in the mind of the operator as that which is understood, and not as the image whereby he understands, which is a form that makes the intellect in act. For the form of the house in the mind of the builder, is something understood by him, to the likeness of which he forms the house in matter. Now, it is not repugnant to the simplicity of the divine mind that it understand many things; though it would be repugnant to its simplicity were His understanding to be formed by a plurality of images. Hence many ideas exist in the divine mind, as things understood by it; as can be proved thus. Inasmuch as He knows His own essence perfectly, He knows it according to every mode in which it can be known. Now it can be known not only as it is in itself, but as it can be participated in by creatures according to some degree of likeness. But every creature has its own proper species, according to which it participates in some degree in likeness to the divine essence. So far, therefore, as God knows His essence as capable of such imitation by any creature, He knows it as the particular type and idea of that creature; and in like manner as regards other creatures. So it is clear that God understands many particular types of things and these are many ideas.

Reply to Objection 1: The divine essence is not called an idea in so far as it is that essence, but only in so far as it is the likeness or type of this or that thing. Hence ideas are said to be many, inasmuch as many types are understood through the self-same essence.

Reply to Objection 2: By wisdom and art we signify that by which God understands; but an idea, that which God understands. For God by one understands many things, and that not only according to what they are in themselves, but also according as they are understood, and this is to understand the several types of things. In the same way, an architect is said to understand a house, when he understands the form of the house in matter. But if he understands the form of a house, as devised by himself, from the fact that he understands that he understands it, he thereby understands the type or idea of the house. Now not only does God understand many things by His essence, but He also understands that He understands many things by His essence. And this means that He understands the several types of things; or that many ideas are in His intellect as understood by Him.

Reply to Objection 3: Such relations, whereby ideas are multiplied, are caused not by the things themselves, but by the divine intellect comparing its own essence with these things.

Reply to Objection 4: Relations multiplying ideas do not exist in created things, but in God. Yet they are not real relations, such as those whereby the Persons are distinguished, but relations understood by God.

Objection 1: It seems that there are not ideas in God of all things that He knows. For the idea of evil is not in God; since it would follow that evil was in Him. But evil things are known by God. Therefore there are not ideas of all things that God knows.

Objection 2: Further, God knows things that neither are, nor will be, nor have been, as has been said above (A[9]). But of such things there are no ideas, since, as Dionysius says (Div. Nom. v): "Acts of the divine will are the determining and effective types of things." Therefore there are not in God ideas of all things known by Him.

Objection 3: Further, God knows primary matter, of which there can be no idea, since it has no form. Hence the same conclusion.

Objection 4: Further, it is certain that God knows not only species, but also genera, singulars, and accidents. But there are not ideas of these, according to Plato's teaching, who first taught ideas, as Augustine says (Octog. Tri. Quaest. qu. xlvi). Therefore there are not ideas in God of all things known by Him.

On the contrary, Ideas are types existing in the divine mind, as is clear from Augustine (Octog. Tri. Quaest. qu. xlvi). But God has the proper types of all things that He knows; and therefore He has ideas of all things known by Him.

I answer that, As ideas, according to Plato, are principles of the knowledge of things and of their generation, an idea has this twofold office, as it exists in the mind of God. So far as the idea is the principle of the making of things, it may be called an "exemplar," and belongs to practical knowledge. But so far as it is a principle of knowledge, it is properly called a "type," and may belong to speculative knowledge also. As an exemplar, therefore, it has respect to everything made by God in any period of time; whereas as a principle of knowledge it has respect to all things known by God, even though they never come to be in time; and to all things that He knows according to their proper type, in so far as they are known by Him in a speculative manner.

Reply to Objection 1: Evil is known by God not through its own type, but through the type of good. Evil, therefore, has no idea in God, neither in so far as an idea is an "exemplar" nor as a "type."

Reply to Objection 2: God has no practical knowledge, except virtually, of things which neither are, nor will be, nor have been. Hence, with respect to these there is no idea in God in so far as idea signifies an "exemplar" but only in so far as it denotes a "type."

Reply to Objection 3: Plato is said by some to have considered matter as not created; and therefore he postulated not an idea of matter but a concause with matter. Since, however, we hold matter to be created by God, though not apart from form, matter has its idea in God; but not apart from the idea of the composite; for matter in itself can neither exist, nor be known.

Reply to Objection 4: Genus can have no idea apart from the idea of species, in so far as idea denotes an "exemplar"; for genus cannot exist except in some species. The same is the case with those accidents that inseparably accompany their subject; for these come into being along with their subject. But accidents which supervene to the subject, have their special idea. For an architect produces through the form of the house all the accidents that originally accompany it; whereas those that are superadded to the house when completed, such as painting, or any other such thing, are produced through some other form. Now individual things, according to Plato, have no other idea than that of species; both because particular things are individualized by matter, which, as some say, he held to be uncreated and the concause with the idea; and because the intention of nature regards the species, and produces individuals only that in them the species may be preserved. However, divine providence extends not merely to species; but to individuals as will be shown later (Q[22], A[3]).