Thesis.
SECTION XIII: ON THE OMNISCIENCE OF GOD
Thesis.
§ 243. By His nature, God is omniscient and His knowledge is infinite. Because God made creatures endowed with the ability to know and to understand, therefore He is also an intelligent being. Ps. 94:9–10: “He who planted the ear, does He not hear? He who formed the eye, does He not see? … He who teaches man all knowledge. The Lord knows the thoughts of men.” By this the psalmist is saying that because God made man knowing and understanding, therefore He must also be knowing and understanding.
The knowledge of God is not in Him in the manner of a habit [habitus]58 added to His essence but is attributed to Him as an utterly pure act, for God knows all things with His essence, not with a habit of knowledge. In the act of knowing, however, He has no need of intelligible representations [species intelligibiles],59 but He knows and sees all things by, through, and in Himself. Accordingly, He also does not conclude one thing from another discursively by reasoning nor does He know one thing after another successively. Rather, He looks upon all things with one simple understanding, not in time and with movement but with one eternal and unchangeable act of understanding and in one moment. The fact that “foreknowledge” is attributed to God happens with respect to us—for to Him all things are present that to us are still future—and with respect to things that take place in time, because God knows them from eternity. Consequently, as God is (1) infinite, (2) eternal, (3) utterly simple, (4) unchangeable, (5) incomprehensible, so the omniscience of God is (1) infinite, (2) eternal, (3) utterly simple, (4) unchangeable, and (5) incomprehensible to our reason. As God is the most perfect being, so also He knows all things most perfectly—not through an uncertain conjecture but through certain and infallible knowledge, not in a confused and general way but distinctly and particularly.
§ 244. The knowledge of God is distinguished: (1) Into general and special knowledge. God’s general knowledge extends to all, for He knows all things and the causes of things; He knows universals and particulars, good and evil things, all things taken together and taken individually. God’s special knowledge pertains only to the elect, for He knows from eternity those who finally and perseveringly will believe in Christ, whom He also elects to eternal life (Rom. 8:29; 1 Pet. 1:2).
(2) Into theoretical and practical knowledge. Theoretical knowledge is that by which God simply and absolutely knows all things. Practical knowledge is that by which God knows some things with regard to the fact that He also does those things. It also is called knowledge of good pleasure and of approval. The former extends to all things, the latter only to good things. The former is distinct from His will, the latter is united with it. The former acts in itself, the latter acts in something else. The former is not a cause of things, but the latter is a cause of things. As an example of the former, a medium has the foreknowledge that a sick person will die on the next day. As an example of the latter, a robber has the foreknowledge that on the next day he is going to kill the person on whom he lays his violent hands. Another distinction is akin to this one. In it God’s knowledge is distinguished in three ways: (a) There is God’s bare knowledge, (b) the knowledge of approval (Ps. 1:6; Matt. 7:23: “I never knew you”), (c) judicial knowledge, by which He punishes impiety and rewards piety.
(3) Into the knowledge of vision and the knowledge of simple understanding. The knowledge of vision is that by which God knows and sees the things that now are and truly will be, as if present. (Elsewhere it is called intuitive and definite knowledge.) With it, God sees both Himself and all things that exist. He sees Himself in Himself. Other things He sees first in Himself as the supreme cause of all things and the universal principle; second, in the proximate causes from which they proceed; third, in themselves insofar as all the things that God sees by means of this knowledge were, are, or will be. The knowledge of simple understanding is that by which God in His own omnipotent essence knows those things that can happen and be but that will never happen and never will be, but not in Himself as an actual principle and as willing (because He is unwilling for them actually to happen and exist) nor in their second causes (because they have none) nor in themselves (because they will never exist). (Elsewhere this is called abstract and indefinite knowledge.)
(4) Into the knowledge of past and present things and the foreknowledge of future things. However, this distinction must not be accepted with respect to God, for, properly speaking, just as He does not “remember” past things so also He does not “foreknow” future things. As He knows and embraces temporal things with eternal knowledge, finite things with infinite knowledge, changeable things with unchangeable knowledge, transient and passing things with a fixed and unmoving knowledge, distinct things with an utterly simple knowledge, so also He knows and embraces future things with a present knowledge. But with respect to us and to the things themselves (which considered in themselves are past, present, future), foreknowledge is attributed to God.
(5) Into natural or necessary, free, and middle knowledge. The natural knowledge of God is that by which He knows Himself and all possible things. His free knowledge is that by which He knows all other beings. His middle knowledge is that by which He knows that if this should exist, then that will exist. God’s necessary knowledge precedes every free act of the divine will. His free knowledge follows the act of His will. Middle knowledge indeed precedes the act of His will but, on the hypothesis thereof, it sees something as future. Becanus, Theol. schol., p. 1, c. 10, q. 1: “Natural knowledge is that by which God knew all possible things from eternity before every free decree of His will. Free knowledge is that by which He determined and knew absolutely all future things after the decree of His will. Middle knowledge is that by which He knew from eternity—not absolutely but conditionally—what humans and angels would do by their own freedom if they were placed with these or those circumstances in such or such an order of things.”
§ 245. The omniscience of God is proved by: (I) Scripture, and that: (1) Affirmatively (
). Job 28:24: “He looks to the ends of the earth and sees everything under the heavens.” In 1 Sam. 2:3 He is called “the God of knowledges.” 1 Sam. 16:7: God sees “not as man sees, for a man sees toward the eyes (that is, he sees what is in front of his eyes), but the Lord sees toward the heart (that is, He sees what is in the heart).” 1 Kings 8:39: “You alone know the hearts of all the sons of men.” Ps. 94:11: “The Lord knows the thoughts of men.” Ps. 139:1–4, 6, 12: “O Lord, You have searched me and known me. You have known my sitting down and my rising up, You have understood my thought from afar (namely, from eternity with one, simple consideration). “You have winnowed my path and my lying down and are acquainted with all my ways. Because a word is not on my tongue, behold, Lord, You know it altogether…. Such knowledge is too wonderful for me. It is lofty, and I cannot (attain) it…. Even the darkness will not hide me; the night will be bright as the day, for darkness is as light.” (Before You the darkness is as light and light as darkness.) Acts 15:18: “All His works are known from eternity.” 1 John 3:20: “God knows all things.”
(2) Negatively (
). Job 42:2: “No thought is forbidden (or hidden) from You.” Ps. 139:[15]: “My frame was not hidden from You when I was made in secret.” Heb. 4:13: “Before Him no creature is hidden and invisible.”
(3) Metaphorically and figuratively (
For when it attributes “eyes” to God, this signifies His omniscience, because He looks upon all things personally, as if He were contemplating all things with His own eyes. 2 Chron. 16:9: “The eyes of the Lord wander throughout the entire earth.” Ps. 11:[4]: “His eyes will behold and His eyelids will test the sons of men.” Sirach 23:[19]: “The eyes of the Lord are ten thousand times brighter than the sun; they look down upon all the ways of men and perceive even the hidden places.” Also, when God is called “light,” among other things, His omniscience is also being denoted, for when something is known, it is said to be bright and clear. 1 John 1:5: “God is light, and there is no darkness in Him.” Luke 12:7: “Every hair of your head is numbered,” that is, God knows you and all that you have so certainly, distinctly, and infallibly, as if He had numbered everything, including your hairs. To this pertains the apostle’s statement: “All things are naked and laid bare to His eyes” (Heb. 4:13). Isidore of Pelusium explains that in this way: “These words have been taken by transferal from victims that are used for the sacrifices and were written by Paul, a man endowed with outstanding wisdom. When those sacrificial victims are skinned, they obviously lose every covering, reveal the state and disposition of their concealed inner parts, and are cut up so all their bones and limbs may be investigated. In the same way, nothing is hidden from God’s sight” (bk. 1, epist. 94, p. 25). Some translate the Hebrews passage using the words “on their backs” so that the metaphor is taken from those who, because they are on their backs, have their faces exposed to someone else’s eyes.
§ 246. (II) Reason: (1) By the way of negation. Ignorance is a defect and imperfection. But God is utterly perfect and sufficient to Himself. Therefore every ignorance must be removed from Him. (2) By the way of causality. God rules all things in the entire universe and directs them to fitting ends, even those things that lack understanding and reason. Therefore He foreknows and sees all things. Because all things that exist have their being from God, how would the knowledge of God not extend to all things that He has brought forth? Will the artisan not know His own handiwork? (3) By the way of eminence. God has made intelligent and knowing creatures, namely, angels and humans. Therefore He understands and knows in a way far more perfect and eminent. (See Ps. 94:10.)
§ 247. (III) The statements of the fathers. In Prochorus’s Historia, vol. 1, Orthodoxogr., p. 87, God is called “all-seeing.”
Polycarp, Epist. ad Philippenses, writes: “God sees all things, and nothing is concealed from Him, neither thought nor conscience nor anything concealed in the heart” (Orth., vol. 1, part 2, p. 3).
Justin, Apolog. 1. pro Christ., p. 39: “We know that God is all-seeing and righteous.” Apol. 2., p. 467: “It is impossible for anything to be hidden from God, not only what is done but also what is thought.” Dial. cum Tryph., p. 279: “God, in His own place, wherever He abides, seeing keenly and hearing keenly not with eyes nor ears but with an indescribable power, both oversees all things and knows all things, and not one of us escapes His notice.”
Tertullian, Adv. Marcion, bk. 2: “The foreknowledge of God has as many witnesses as there are prophets made by Him.”
Origen, Epist. Rom., bk. 1: “He is very wicked who does not believe that this is in God: that He sees in the future what we see in the past.”
** Lactantius, bk. 6, c. 24: “He in whose sight we live knows all things. If we were able to conceal something from all humans, we cannot conceal it from God, to whom nothing can be hidden, nothing can be secret.” **
Hilary, on Psalm 129: “Everywhere and in every way He completely hears all things, completely sees all things, completely knows all things.”
Augustine, De civ. Dei, bk. 5, c. 9: “To confess that God exists and to deny His foreknowledge of future things is the most obvious insanity.” Commentary on Psalm 7: “God is said to look at reins and hearts when He sees the thoughts of all (which is meant by the word “heart”) and the delights of all (which are understood by the word “reins”).” On Psalm 93: “Will not He who has made you cast His eye upon you? Whether you want Him to or not, He sees you, and there is nowhere to hide yourself from His eyes.” On Psalm 136: “God is wholly eye because He sees all things.”
** Augustine again (epistle 111): “The eyes of humans are warded off by walls, but the divinity of God cannot be warded off by our internal organs from searching into and knowing the entire man.” **
Antithesis.
§ 248. (I) The heathen outside the Church denied God’s foreknowledge because they could not reconcile the freedom of human will with the immutability of God’s foreknowledge. Augustine, De civ. Dei, bk. 5, c. 9: “In his book on divination, Cicero refuted the Stoics in such a way as to deny that there is knowledge of future things, and he argues this with all his might that neither in God nor in man is there any prediction of events. In this way he both denies the foreknowledge of God and with his empty arguments tries to subvert every prophecy, even those that are clearer than light.” Here we should mention that Averrhoes denies “that God knows individual things” (Metaph., bk. 12).
(II) Within the Church, the Agnoetae removed omniscience from Christ. There were two kinds of Agnoetae. Some, the Phtartolatrae, denied an ignorance of the Last Day not to the divinity but to the soul of Christ. Nicephorus discusses these in Hist. eccles., bk. 18, c. 50. Some, on the other hand, attributed that ignorance to the divinity itself. Rabanus discusses these in De inst. cleric., bk. 2, last chapter. (Cf. Gregory, bk. 8, epist. 24.)
§ 249. [III] In many ways Vorstius undermines God’s omniscience. Disp. de Deo, p. 311: “Of itself God’s wisdom certainly does not require God to have foreknown each and every event that is now occurring in the world from eternity with the absolute knowledge of vision.” Ibid.: “Nothing, generally speaking, forbids that such a thing is discursive in God, by which He wills one thing to be or occur one after another, or again one because of another. In fact, sound reason demands that, because free choice [proaeresis] truly has a place in God, with respect to all of those things that exist or occur outside of it, a sort of discursive thinking [
]—but divine and utterly free from every defect—should also find a place in Him.”
On p. 270 he denies that God’s knowledge is His very essence. He says: “The act of knowing by which God specially and distinctly knows created things outside Himself—individual things, for example—or by which He understands a thing by considering it personally does not at all pertain to God’s essence. That is, it is not God Himself but an activity of the divine mind that can have no place in God without the mediating action of free will.” p. 441: “Those seem to answer more fully who teach that there is a certain universal knowledge of God in general, but nevertheless in such a way that they acknowledge more causes of certainty in the vision of things present and past than in the vision of future contingents. In this way they claim that the hope and expectation of these events is somewhat uncertain, comparatively speaking.” p. 451: “At some time God was afraid in His own way. That is, He deservedly suspects and prudently guesses that this or that evil will arise.” p. 266: “Heaven forbid that we should attribute to God either hypocrisy or rashness and imprudence of such a type that, it seems, would be induced by an infallible preconception of all future events.” p. 275: “Those who extend the foreknowledge of God universally, simultaneously, and equally—or much in this way—to all events that occur, both necessary and accidental, evil as well as good, without discrimination, I say those who do this subvert our freedom of choice and every contingency of events. In fact, in the end they obviously establish God as the author of sin.” (See also his Apol. exeg., c. 23, which is clearly shaped in Photinian style.)
§ 250. [IV] When the Photinians deny “that God foreknows the future sins of humans,” in this area they are following the Albanenses, who around AD 796 argued that “God does not foreknow any evil of Himself but through His adversary, the demon.” Socinus, Prael. theol., c. 8–11: “No rational argument and no testimony of Scripture can be brought forth from which it is concluded clearly that God knew the evils that depend on the wills of humans before they happened.” (But in this way he is claiming that God is changeable. For if God in time actually knows something He did not know from eternity, He changes from ignorance to knowledge, and thus an accident belongs to Him.) In c. 10, p. 38, he proposes this rule: “If a testimony of Scripture should speak about either good or evil works, it can happen that the prediction is only on the basis of similar works and for this reason is not certain nor from foreknowing.” Schmalz has similar words in his Refut. disp. post 12. D. Frantz., pp. 427, 432, 437. (However, there is no certain and determined truth of similar and contingent works. Therefore if God knows future events only on the basis of similar ones, His knowledge will not be sure and infallible but fallacious.)
Let Scripture declare the contrary clearly. Isa. 41:22[–23]: “Let them come near and tell us what is to happen [accidentia futura].” (For thus it is used in Gen. 42:29; 44:29; Isa. 26:13.) “Tell us the former things,” what they were, “and we will set our heart and know their end; and cause us to hear the things that are to come. Tell us what is to come afterward, that we may know that you are gods.” From this passage we draw the following conclusion: We must attribute to God the sort of foreknowledge of future events through which He may be distinguished from creatures and false gods. But the foreknowledge of future events drawn only from similar things does not distinguish God from creatures and false gods. Therefore. Also, whatever foreknowledge of future events removes the certainty of God’s prophecies, undermines their infallibility and the truthfulness of Holy Scripture, and transforms the divine majesty that belongs to the true God alone into an accident common to the devil and humans, that foreknowledge must not be attributed to God. But a foreknowledge of future events drawn from similar things is that kind of foreknowledge. Finally, whatever foreknowledge of future events is proved by the outcome itself to be certain and infallible, that foreknowledge is not drawn only from similar things. But divine foreknowledge is proved to be certain and infallible from its outcome. For example, in this way He foretold the oppression of the Israelites in Egypt (Gen. 15:13) and their idolatry (Deut. 31:16); in this way He prophesied all the things that happened to Christ in His Passion, all of which and similar things were proved by their outcome. The fact that the citizens of Keilah would surrender David into the hands of Saul was purely contingent, yet God foreknew that had David stayed in the city, the people of Keilah would have surrendered him (1 Sam. 23:12). (See our De glor. Dei, disp. 10, § 16.)
Questions concerning the omniscience of God.
§ 251. (I) The question arises: Is divine omniscience undermined by the fact that God is said to forget our sins (Ezek. 18:22)? We respond. Not at all, because that forgetfulness is not the opposite of bare knowledge but of the judicial recognition by which God knows sins in such a way that He inflicts them with merited punishments. God forgets sins not 
, affectively, so that He no longer has a knowledge of them, but 
, effectively, insofar as He does not send the punishments of sins. Let the judgment be the same on those complaints of the saints in which God is said to have forgotten them, that is, in which they do not sense God’s help.
§ 252. (II) The question arises: Does Gen. 18:21 conflict with divine omniscience, because it says, “I shall go down and see whether the people of Sodom have filled up their iniquities”? We respond. These words must be understood as using the figure of anthropopathism. He is said to see the sins of humans when by the very fact, that is, by the imposition of punishments, He shows that He neither is unaware nor approving of the sins. For it is clear that the crimes of the Sodomites were not unknown to God because He hints in His conversation with Abraham that not even ten righteous people were left in those cities (Gen. 18:32). The devout ancients also add this: God says He will come down to see whether the Sodomites have filled up their iniquities in order that magistrates and judges might be taught not to decide on punishments without correctly understanding and examining the situation.
§ 253. (III) The question arises: How can the knowledge of God be infinite when He does not know actually infinite things? We respond. On the contrary, God perfectly knows not only created, finite beings but also the infinite being itself, namely, Himself. Surely, then, He knows an infinite object. Furthermore, God knows finite things not with a finite but with an infinite knowledge in the same way as He effects finite things not with a finite but with infinite power. For as His power is neither terminated nor limited by the production of finite things (because He does not act with the entire activity of His power, but a greater power always remains after the work has been done), so also His knowledge is neither terminated nor limited by a knowledge of finite things (because His knowledge always extends further). Although He knows not only the things that are but also the things that are not, nevertheless things that are infinite can exist through divine power. (See our commonplace On Providence [Commonplace IX], § 30.)
§ 254. (IV) The question arises: Does the use of the doubting adverb “perhaps, perchance” (Jer. 26:3; Matt. 11:23) conflict with the certain and infallible foreknowledge of future contingents? We respond. Those adverbs are not related to the infallibility of divine foreknowledge but to the freedom of the human will. Jerome, on Ezekiel 2: “God says this [“If they perhaps would listen”] with the disposition of doubt to show the free choice of man, lest the unchangeable foreknowledge of future events should make unchangeable what God knows is going to happen. For it is not because He knows the future that it is necessary for us to do what He has foreknown; instead, because we by our own will are going to do something, He knows that it will happen.” Gregory, In Ezech., homil. 18, asserts that “the effects of difficulties are being indicated.” Furthermore, the Hebrew 
and the Greek 
express the mind not so much of one who doubts as of one who hopes for good and confirms it.
§ 255. (V) The question arises: Does God’s foreknowledge take away the freedom of human choice? According to Pererius, Comment. in Rom., c. 9, num. 79, Cajetan says: “If anyone were to ask me to show the connection of these to each other, I, for my part, would answer that a true thing is not contrary to a true thing but that I do not know how those two are associated with each other. In the same way, I do not know the mystery of the Trinity, which I nevertheless do believe, even as I believe the other mysteries of the faith.” Nevertheless so that we may in some manner explain in what regard the certainty and immutability of divine foreknowledge does not take away the contingency of events and the will of human freedom, we must distinguish between the necessity of the consequent (which is elsewhere called absolute, preceding, and simple necessity)—which stems from a necessary and intrinsic connection of cause with effect—and the necessity of the consequence (which is elsewhere called hypothetical, following, accompanying, conditional, suppositional necessity)—which stems from the actuality of existence from the positing of an effect, because everything that exists, by the fact that it does exist, exists necessarily.60 Concerning this latter type of necessity with respect to divine foreknowledge, those things are necessary that occur contingently from causes and from agents acting freely. This necessity does not take away freedom but presupposes it, something that Augustine explains in this way (De civ. Dei, bk. 5, c. 9):
It is not a consequence that if, for God, there is a definite order of all causes, there is thus nothing left for the choice of our will. In fact, our wills are in the order of causes that for God is definite and that is contained in His foreknowledge, because human wills also are causes of human works. And thus He who has foreknown all the causes of things surely could not have been ignorant of our wills, which are also among those causes, which wills He also foreknew were the causes of our works. How, then, could the order of causes (which is definite for the foreknowing God) cause nothing to be left to our will, when our wills have a great place in the order of causes itself?
De lib. arbitr., bk. 3, c. 4: “As you with your memory do not compel things that have passed to have been done, so God with His foreknowledge does not force things to occur that are future.” Boethius uses this reasoning: “It does not conflict to say that something will exist contingently. Therefore it does not conflict to know this, and as a consequence, the knowledge of a future contingent does not remove its contingency.” The antecedent is proved because “will exist contingently” says only two things, namely, “will exist” and “is possible not to exist.” But these two statements are not opposed to each other because just like many things can happen that will not happen, so many things will happen that could not happen. Therefore many things will happen contingently. Now, what will exist contingently will exist truly; therefore it can be foreknown. For everything that is true is knowable. Therefore knowledge does not remove contingency. (See our commonplace On Providence [Commonplace IX], § 35.)
Concerning the other questions—as, for example, (1) Does God know all things outside Himself distinctly? (2) Does He know them through ideas? (3) Does He have foreknowledge of nonbeings? (4) Is God’s foreknowledge the cause of things? (5) Does God know the evils of fault61 and how? (6) Is God’s foreknowledge invariable?—I say, we have discussed these questions in our article On Providence [Commonplace IX] and commentators on Thomas ([ST,] p. 1, q. 14) debate them in detail.
The practical use of the doctrine of God’s omniscience.
§ 256. (I) Consoling: (1) In adversities. God is omniscient; therefore He sees our afflictions, our anguishes. Not only does He see them, He is also touched with pity because He is our kind Father. Ps. 10:14: “You see it, for You consider labor and affliction…. The poor man is left to You.” In Exod. 3:7 Jehovah says: “I have seen the affliction of My people.”
(2) In perils. The all-overseeing God sees the snares our foes have set for the Church and for every truly devout person. Therefore we are not excessively distressed in our mind when we face perils. Ps. 142:[3]: “When my spirit is faint within me, You know my way. In the path where I walk they have hidden a snare for me.”
(3) In false accusations. Ps. 1:6: “The Lord knows the way of the righteous.” Therefore even if they have been exposed to various false charges and accusations, they should lift themselves up with this consolation: that God knows their heart.
§ 257. (II) Exhorting: (1) To avoid sin. The eyes of the Lord are open over all the sons of men; all things are bare and open to His eyes. Therefore let us beware of sins, which we cannot commit in a place so secret that they escape His sight and view. When Thales was asked, “Are the deeds of humans hidden to God?” he answered, “Not even their thoughts, so that we want to have not only pure hands but also pure minds, because we believe that the Deity in heaven is present with our thoughts.” Valerius Maximus, bk. 7, c. 1. Sirach 23:[18–19]: “A man who breaks wedlock thinks to himself: ‘Who sees me? Darkness and walls hide me so that no one can see me. Whom should I fear?’ He does not realize that the Lord’s eyes are brighter than the sun and see all things that men do, even in the most hidden corners.” Job 34:21–22: “The eyes of the Lord are upon the ways of men, and He sees all their steps. There is no darkness nor shadow of death that evildoers may hide themselves there.”
(2) To flee hypocrisy. The omniscient God sees the most intimate, most secret recesses of the heart. We must, then, beware of the hypocrisy that veils the secret wickedness of the heart with the external appearance of honesty. Jer. 17:[9–]10: “The heart of man is depraved and inscrutable. Who will know it? I, the Lord, searching the heart and testing the reins, give to each according to his ways, according to the fruit of his inventions.”
(3) To confess our iniquities to God. Ps. 32:[3]: “Because I kept silent, my bones grew old,” etc. Prov. 24:12: “He who weighs the heart understands.” Augustine, Confess., bk. 10, c. 2: “O Lord, what would be hidden in me, even if I were unwilling to confess it to You, to whose eyes the abyss of human conscience is bare? For I would hide You from me, not me from You. But now because my groaning is witness that I am displeasing to You, You shine forth and are pleasing and are loved and desired, that I may be ashamed of myself, renounce myself, select You, and please neither me nor You except in regard to You.”