7.2 Aquinas on God’s Knowledge (SCG 1, 44–71)
7.2 Aquinas on God’s Knowledge (SCG 1, 44–71)
When it comes to God’s knowledge, Aquinas’s main claims are:
1. God has intellect or understanding (SCG 1,44).
2. God’s act of intellect is his essence (SCG 1,45).
3. God understands by nothing except his essence (SCG 1,46).
4. God understands himself perfectly (SCG 1,47).
5. Primarily and essentially, God knows only himself (SCG 1,48).
6. God knows things other than himself (SCG 1,49).
7. God has a proper knowledge of all things (SCG 1,50).
8. There is no habitual knowledge (habitualis cognitio) in God (SCG 1,56).
9. God’s knowledge is not discursive (discursiva) (SCG 1,57).
10. God does not understand by composing and dividing (componentis et dividentis) (SCG 1,58).
11. God knows truths that we articulate by composing and dividing (SCG 1,59).
12. God is not only truth but the purest truth and the first and highest truth (SCG 1,60, 61, and 62).
13. God knows singulars, things that are not, future contingent singulars, the thoughts of the mind and the motions of the will, infinite things, lowly or trifling things (vilia), and evils (mala) (SCG 1,65–71).
7.2.1 God as Intelligent (SCG 1,44)
Aquinas’s first set of arguments for God having intellect or being intelligent draws on his thinking about motion in SCG 1,13. Aquinas says that God must have intellect since God is the first self-moving being. He notes that self-moving things in the world are not completely self-moved since they are moved by appetite and knowledge. So, he reasons, the first unmoved mover must have in itself what corresponds to desire or knowledge in secondary movers. It cannot possess desire considered as an appetite for what is pleasing to the senses, but it can desire what is good without qualification. In that case, however, it must have knowledge of what is good without qualification. Indeed, Aquinas goes on to say, this conclusion follows even if we start by taking God to be not “a first self-moving being” but “an absolutely unmoved mover.”3 Why so? Because “the first mover is the universal source of motion” and because “since every mover moves through a form at which it aims in moving, the form through which the first mover moves must be a universal form and a universal good.”4 Aquinas holds that a form does not “have a universal mode except in the intellect,” thereby drawing the conclusion that “the first mover, God, must be intelligent.”5 He goes on to observe that God must also be intelligent since there are many intelligent movers in the world all of which are instruments of God, and since it is never the case “that an intellectual mover is the instrument of a mover without an intellect.”6
Following these motion-oriented arguments, Aquinas defends the claim that God is intelligent with four others not drawing on motion.
The first applies Aquinas’s claim that intellect as active involves the existence of form without matter.7 We read: “Forms that are understood in act become one with the intellect that understands them in act. Therefore, if forms are understood in act because they are without matter, a thing must be intelligent because it is without matter. But we have shown that God is absolutely immaterial. God is, therefore, intelligent.”8
In the second argument Aquinas holds that, since God contains the perfections of creatures while being totally simple, God must contain the perfection of intellect, which, as Aristotle says, extends to all things and can contain them in understanding.9
In the third argument Aquinas maintains that God sets ends for things in nature, which implies intellect on his part. God “could not set an end for nature unless he had understanding. God is, therefore, intelligent.”10
Finally, argues Aquinas: (1) the perfect is “prior” to the imperfect as act is prior to potency, (2) forms existing in particular things are imperfect since they are limited by that in which they exist, (3) such forms must derive from unlimited forms, which can only exist as objects of understanding “since no form is found in its universality except in the intellect,”11 (4) if such forms were to exist as subsisting things, they would be intelligent, and (5) therefore, God, “Who is the first subsistent act, from whom all other things are derived, must be intelligent.”12 I should note that Aquinas is not here saying that there are many subsistent forms in which things in the world “participate” in some way. He does not believe that there are, and he rejects Plato’s theory of forms as it is commonly construed, as holding that forms exist as objects in a nonmaterial realm (see section 7.2.1 above). In SCG 1,44 he is arguing that forms limited by existing in particular material things must derive from a form not so limited, a form that, if it were to subsist, would have to do so as having intellect, as Aquinas takes God to have.
7.2.2 “God’s Understanding Is the Divine Essence” (SCG 1,45)
You will, I hope, not be confounded to find Aquinas saying in SCG 1,45 that God’s understanding is his essence. Given his SCG explication of divine simplicity, he could hardly say anything else. Aquinas holds that all that is in God is God, that there is no distinction between the individual God is and the nature that God has, and that there is no distinction between God’s essence (essentia) and existence (esse). Such a position seems to entail that if God has knowledge, that knowledge is not an attribute that God has but is nothing other than the being or essence of God. As Aquinas writes in SCG 1,45: “Whatever is in God is the divine essence. God’s act of understanding, therefore, is his essence, it is the divine being, God himself. For God is his essence and his being.”13 This line of thought runs through all of the arguments in SCG 1,45, so I shall not here try to represent each of them in detail.
7.2.3 God Understanding through the Divine Essence and as Understanding God (SCG 1,46–48)
As I have said, Aquinas thinks that we understand as forms come to be in us immaterially at least partly because of the sensory impact on us of things in the world.14 He refers to these forms as intelligible species (ideas) by which we understand, so he regards them as causing us to know or understand.15 With this notion in mind, in SCG 1,46 Aquinas denies that God understands by means of intelligible species as these come to be in people. Why? Because he takes God to be totally simple and lacking in parts that might help him to function in some way or other. We understand by means of intelligible species, he thinks, but he also argues that, given divine simplicity, God’s understanding has to be what the divine essence is, not something deriving from what is in God while being distinguishable from the divine essence. Or, as Aquinas says in SCG 1,46, if “the divine intellect understood by an intelligible species other than the divine essence, something other would be added to the divine essence as principle and cause.”16 In SCG 1,46 Aquinas goes on to argue that God can only understand through his essence since there is no actualized potentiality in God and since there are no accidents in God. According to Aquinas, we come to know by means of intelligible species, which are accidents that arise in us, but there is no coming about in God, which means that God’s understanding is, so to speak, a function of his essence, or that God’s understanding is his essence. He writes: “God’s understanding, as we have shown, is his essence. If, therefore, God understood through a species that was not his essence, it would be through something other than his essence. This is impossible. Therefore, God does not understand through a species that is not his essence.”17
In short, the “big idea” in SCG 1,46 is that God cannot understand because something that comes to be in him causes him to do so. For Aquinas, there is understanding in God just because the divine essence exists. And because he thinks this, Aquinas proceeds in SCG 1,47 and 48 to argue that God must understand himself perfectly and that what God knows by essence or through himself (per se) is himself. If the divine essence is what stands to God as a source of knowledge comparable to intelligible species in people, says Aquinas, then this essence must be “perfectly conformed to the thing understood” and must be “perfectly joined to the intellect.”18 Yet Aquinas continues: “The divine essence, which is the intelligible species by which the divine intellect understands, is absolutely identical with God, and it is absolutely identical with his intellect. Therefore, God understands himself most perfectly.”19 Again, Aquinas argues, “that by which God understands is nothing other than his essence. Therefore, the primary and essential object of his intellect is nothing other than God himself.”20 Aquinas believes that God understands things other than himself, but he denies that it belongs to God to do so primarily or essentially (per se).21 In SCG 1,48 Aquinas offers seven arguments for this conclusion, but central to his thinking in this chapter is the idea that God does not have to know what is not divine in order to be God, who knows himself perfectly through his essence. In Aquinas’s view, though God does in fact know or understand what is not divine, his doing so is not required for him to exist as knowing. Basically, the reasoning here is: (1) God could exist without knowing what is not divine, but (2) he could not exist without knowing himself perfectly, so (3) primarily and essentially God knows only himself.
7.2.4 God’s Knowledge of What Is Not God (SCG 1,49–50)
How, though, does Aquinas think of God as knowing things other than God? One often finds it said, especially by those who favor the formula “God is a person,” that God’s knowledge of what is not divine arises by observation, by taking a look at things in some way. Such, however, is not Aquinas’s view. When we know things by observing or looking at them we gain or acquire knowledge on the basis of sensory experience. So knowledge grounded in observation amounts to the actualizing of a potentiality and is caused in us by what is distinct from us. As I have shown, however, Aquinas denies both that there is potentiality in God and that anything in God is caused by what is not divine. When it comes to God’s knowledge of other things, therefore, the line Aquinas takes in SCG 1,49 is that God knows other things by knowing himself as their cause.
In understanding himself, says Aquinas, God must understand himself as the cause of what he produces, the cause of all creatures, for that is what God is.22 God “is through his essence the cause of being for other things.”23 He adds: “Since he has a most full knowledge of his essence, we must posit that God also knows other things.”24 Again, says Aquinas: “Since, then, God knows himself perfectly, he knows himself to be a cause. This cannot be unless he somehow knows what he causes. This is other than God, since nothing is the cause of itself. Therefore, God knows things other than himself.”25 Since God is intellectual, Aquinas also reasons, the likenesses of creatures must exist in God intelligibly as he knows and must therefore be known by him. Indeed, Aquinas adds in SCG 1,50: “God knows all other things as they are distinct from one another and from himself. … God knows whatever is found in reality. But this is to have a proper and complete knowledge of a thing, namely to know all that there is in that thing, both what is common and what is proper.”26 One might naturally suppose that if all things other than God exist in God as known properly and completely, then God is made up of many things and is not entirely simple. However, having alluded to this supposition in SCG 1,51, Aquinas dismisses it while arguing that things other than God do not exist as individual things in God but do so in a single act of understanding by which God understands himself and what he produces (SCG 1,53 and 55).
7.2.5 What God’s Knowledge Is Not (SCG 1,56–58)
I have now shown why Aquinas attributes knowledge to God in the SCG and why he thinks that in knowing himself perfectly God knows all that derives from him. Yet what Aquinas says about God knowing or understanding only through his essence clearly shows that he thinks that though we have reason to say that God knows, we also have reason to suppose that knowledge in God differs significantly from knowledge in us. And, as we proceed to SCG 1,56–58, we will find Aquinas noting other ways in which divine knowledge differs from human knowledge. For in these chapters we find him denying that God’s knowledge is habitual, discursive, or arrived at by “composing and dividing.”
By “habitual” knowledge Aquinas means “knowledge that we have without always drawing on it or bringing it explicitly to mind.” We know a lot because we have learned and not forgotten what we learned. But we do not always have these truths in mind since sometimes we fall asleep and sometimes we think about all sorts of different things. We can recall what we have learned, but we do not always have in mind everything that we have learned. According to Aquinas, however, God lacks habitual knowledge. He says: “Where there is habitual knowledge not all things are known together; some are known actually, and some habitually. But, as we have proved, God has actual understanding of all things together. There is, therefore, no habitual knowledge in him.”27 In Aquinas’s view, to possess a habit (habitus) is to have what we might call a disposition or ability on which we can draw as needed, which means that those with habits are things that are potentially thus and so in some way. Yet, says Aquinas, “the divine intellect is in no way in potency.”28
When he refers to “discursive knowledge” in SCG 1,57, Aquinas is alluding to knowledge arrived at through a process of reasoning or ratiocination. Such a process, however, depends on there being potentiality in the reasoner while, according to Aquinas, there is no potentiality in God, and “his knowledge, therefore, is not ratiocinative or discursive, although he knows all discourse and ratiocination.”29 Again, says Aquinas, “God knows all things by one operation” and not by first considering this and then moving on to grasping that.30 In God, Aquinas maintains, there is only “natural” knowledge—meaning “knowledge not arrived at by a process of reasoning.” Ratiocination, says Aquinas, “is a certain motion of the intellect proceeding from one thing to another.”31 Yet God is the only truly unmoved mover, and so must be his intellect as it knows. Among other things, Aquinas goes on to argue that God’s knowledge is not discursive since having to reason to conclusions indicates an imperfection of a kind while God is absolutely perfect. In short, Aquinas thinks that God does not have to strive to know by seeking to figure things out.
As for his denial that God understands by “composing and dividing” (compositio et divisio: literally “putting together and taking apart”), Aquinas’s main point is that God having intellect does not mean that he is able to link or unlink a subject and predicate in a sentence expressing a truth. I might understand what a cat is. I might also understand what being black amounts to. Yet suppose I discover and declare that some cat is black. Or suppose that I recognize that some cat is not black. Then I bring together or separate concepts that I have formed independently of each other. According to Aquinas, however, God’s intellect does not work by attaching discrete predicates to subjects whether in thought or in language. Neither does it work by detaching discrete predicates from subjects. According to Aquinas, God is not a language user and does not acquire concepts over time while bringing them together or separating them for purposes of expressing what he knows. God knows by knowing his essence and by knowing all things while being simple and, therefore, immutable.
In short, Aquinas maintains that God’s knowledge is an “all at once” affair. In his view, as expressed in SCG 1,58, what chiefly has to be said when it comes to God not understanding by composing and dividing is: (1) God knows himself as noncomposite; (2) what God knows in knowing himself is not the result of knowing different things or grasping different concepts and bringing them together or separating them for purposes of assertion or denial; (3) there is no before and after in God. In SCG 1,59 Aquinas accepts that God is not ignorant of truths that we express by linking subjects and predicates together in propositions that we affirm or deny. But he denies that God’s knowledge is arrived at by composing and dividing. He says that truth in an intellect is a matter of the intellect grasping how things are, and he goes on to say that God’s intellect does this without arriving at true propositions as we do. God, thinks Aquinas, can grasp truth that we come to know over time and by reasoning or bringing concepts together. Yet his doing so does not depend on his thinking and arriving at truth as we do. Indeed, Aquinas holds in SCG 1,60 and 61, God himself is truth (veritas) and is the purest truth (purissima veritas), containing no falsity or deception. Aquinas maintains that “truth is a certain perfection of understanding or of intellectual operation”; so God is truth as being perfect understanding and intellect. He goes on to argue: “Truth is not compatible with falsity, as neither is whiteness with blackness. But God is not only true, he is truth itself. Therefore, there can be no falsity in him.”32 In SCG 1,62 Aquinas adds that God is the first and highest truth since he is the first and most perfect being who is truth by his essence and whose intellect and what it understands are totally united.
7.2.6 Some Specifics Concerning What God Knows Other Than God (SCG 1,63–71)
Although SCG 1,49–50 argues in general that God knows what is not divine, those chapters do not descend to details. As I have shown, Aquinas holds that God knows what is not divine by being its maker. But Aquinas is aware of a series of objections to the view that God knows what is not divine, and he draws attention to them in SCG 1,63 while going on to rebut them in SCG 1,65–71. In his rebuttal he claims that God knows singulars (i.e., particular and existing created things), that God knows things that do not exist, that God knows future contingent singulars (i.e., things in the future that do not have to exist as they do), that God knows the thoughts and willings of intellectual creatures, that God knows infinite things, that God knows lowly things, and that God knows evils. Yet why does Aquinas think that God knows these things?
In SCG 1,65 Aquinas argues that God knows singulars, which are all God’s effects, since “He makes them to be in act.” Aquinas adds (1) that God, as the creator of everything, must, by his essence, know the individuality of things composed of matter and form since he makes all that has form and matter, (2) that God must know individual things in the world since, by being their creator, he knows how they break up into members of a genus or species, (3) that God would not be perfectly knowing if he were ignorant of singulars, (4) that God’s knowing power (vis cognoscitiva) exceeds that of human beings, meaning that God, though simple, can know singulars that we come to know by our knowing powers, (5) that God knows particular things since his knowledge is perfect and since he makes things as the particulars that they are, rather as we sometimes bring particular things about by precisely knowing what we plan to bring about, (6) that God must know singulars by being their first mover acting through intellect, (7) that “the likeness of a form in the divine intellect, by reaching to the least of things to which its causality reaches, extends to the singularity of sensible and material form,”33 and (8) that if God were ignorant of singulars, he would be more ignorant than we are since we can know particular things in their particularity.
SCG 1,66 maintains that God, like us, can know what does not exist insofar as God, like us, can understand what something that could exist would be if it did exist. In this connection Aquinas notes (1) that God, like a craftsman, can know what he plans to make even though it does not always exist, (2) that God knows himself perfectly and therefore knows exactly what he can bring about even if what he brings about does not always exist, (3) that, just as we can know what something is even if examples of it are destroyed, God, as maker of all things, can know what particular things that do not now exist were or will be since God has knowledge that we can express by means of propositions, (4) that God as the maker of all things must know what will come to be even if it does not currently exist, and (5) that God as creator must know all that comes to be in the course of time even though there is no change or successiveness in him and that “the divine intellect, therefore, sees in the whole of its eternity, as being present to it, whatever takes place through the whole course of time.”34
In SCG 1,67 Aquinas says that God knows future contingent (i.e., nonnecessitated) singulars in that God knows all that takes place in time “from all eternity” insofar as “it is present” to him.35 If I know that you will run tomorrow, that might be because your running tomorrow is already predetermined by causes operating now of which I am aware; but it does not follow that if you are running now, your running is necessitated in some way, and my knowing that you are running now is compatible with you freely running now. By the same token, Aquinas argues, God can know what is future but not necessitated since God knows the future as present to him. In SCG 1,67 Aquinas also argues as follows:
1. Things or events can be necessary or contingent. God knows whether or not they are necessary or contingent. That is because his knowledge must extend to “the being” that things have in themselves (i.e., it must extend to them being necessary, if they are necessary, and contingent, if they are contingent).
2. God’s knowledge would be imperfect if it did not extend to matters of contingency and necessity. But God knows all things and their causes. So God knows what is both contingent and necessary.
3. Contingent and changing effects can proceed from what is first and necessary, and contingent effects can be known to God even though he is the first and immutable cause that cannot not be.
4. Nothing is future to God since, in his eternity, God unchangeably knows all that was, is, or will be. That is so even though we, who are not eternal, speak of God as knowing what is future to us in a way that might seem to imply that God’s knowledge of events precedes them in time and therefore implies that they cannot not be.
5. It is true that “God knows that such and such is the case” entails that such and such is the case. But this proposition does not entail that the such and such in question is necessary in itself. So God’s infallible knowledge of what was, is, and will be does not rule out the possibility that some things are but might not be, or might not be as they are.
In SCG 1,68 Aquinas ascribes to God knowledge of “motions of the will.”36 He does so because he thinks that such things exist and must be known to God as the creator of all that is not divine. “There is,” he says, “a certain being in the soul and a certain being in things outside the soul,” and “God, therefore, knows all these differences of being and what is contained under them.”37 Furthermore, Aquinas argues, “God knows all things to which his causality extends,” and “it extends to the operations of the intellect and the will.”38 Aquinas also reasons that “just as God, by knowing his being knows the being of each thing, so by knowing his understanding and willing he knows every thought and will.”39
In SCG 1,69, and relying on a line of argument with which we are now very familiar, Aquinas argues that God knows infinite things, if there are such things, since he is their cause and knows the extent of his power, which is infinite and extends to what is potentially infinite (as, Aquinas thinks, the universe is potentially infinite, though containing a number of finite things, since it might, logically speaking, never have had a beginning). He goes on to argue: (1) There “always remains a new way in which some copy is able to imitate the divine essence” and “nothing prevents God from knowing infinite things through his essence”;40 (2) God knows what is infinite since his knowing, like his being, is infinite, and since God, who is infinite, must know himself perfectly; (3) No intellectual perfection can be lacking to God since God is perfect; so God must know what is infinite; (4) Even we can recognize that there may be a potential infinite (e.g., a potentially infinite number of objects); so God must also grasp this fact; (5) We are unable to count an infinite number of things since we cannot go through an infinite process of counting; but, since there is no successiveness in God, he can know the infinite as well as the finite; (6) God can know finite and infinite objects equally well since his knowledge, which is infinite and simple, extends over both of them.
When it comes to God’s knowledge of lowly things, Aquinas again appeals to the idea that God’s knowledge must extend to all that God brings about. Aquinas discusses the topic of God’s knowledge of lowly things while bearing in mind the suggestion that it would somehow detract from God’s excellence if he were to be familiar with what is of little account. His response to this suggestion is to argue that it is because of his greatness that God knows even the most trivial of things. So, we read:
Since God is of an infinite power in understanding … his knowledge must extend even to the most remote things. … If God knows something other than himself, however supreme in nobility it may be, by the same reason he knows anything whatever, however exceedingly lowly it may be called. … He especially knows the order of the universe. But this order cannot be known without a knowledge both of the things that are more noble and of the things that are more lowly. … The lowliness of the things known does not of itself redound to the knower. … The knowledge of lowly things, therefore, does not detract from the divine nobility, but rather belongs to the divine perfection according as it precontains all things in itself.41
God knows evil things, says Aquinas (SCG 1,71) since God knows what is good, implying that he knows its opposite, evil. Aquinas also argues that if God knows what is true, and if God’s knowledge is perfect, then God must know evils since it is true that there are evil things or things that are bad. God, he says, must know how things differ from each other or are contrary to each other, which must involve him knowing that some things are bad or in a bad way. Again, he argues, God must know evil since God knows matter and since material things can suffer privations that amount to evil in them. In SCG 1,71, Aquinas ends up saying (1) that God must know dangers that threaten things because he knows what is best for things, and (2) that it does not count against God’s perfection that he knows of what is evil since knowledge of evil is not blameworthy unless it leads one to give in to or to pursue evil, which is impossible when it comes to God since God is immutable. Aquinas concedes that since God, unlike us, knows by his essence, God’s knowledge of evil does not exist in him as it comes to exist in us since we have potentiality as we come to know while God lacks potentiality. God, says Aquinas, knows of evils because he understands himself and in doing so understands other things, including what is potential or privative as well as what is actual. Yes, says Aquinas, God knows only himself as he knows the good that he is. Yet, Aquinas adds, “because in knowing Himself, He knows the beings that are by nature subject to privations, He must know the privations and the evils that are opposed to particular goods.”42