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Category: SAMT

A tour through Saint Thomas Aquinas’s Summa Contra Gentiles.

August 16, 2015 | 9 Comments

Summary Against Modern Thought: God Knows Infinite Things

This may be proved in three ways. The first...
This may be proved in three ways. The first…
See the first post in this series for an explanation and guide of our tour of Summa Contra Gentiles. All posts are under the category SAMT.

Previous post.


Chapter 69 That God Knows Infinite Things (alternate translation)

[1] WE must next prove that God knows infinite things. For in knowing that He is the cause of things He knows things other than Himself, as was shown above.[1] Now He is the cause of infinite things, if there be infinite things, since He is the cause of whatever is. Therefore He knows infinite things…

Notes Infinity, as I’m frequently pointing out, is not a very large, or even unimaginably large number. It is way beyond any conception of any number; indeed, it is infinitely beyond. We cannot—we are dealing in an impossibility, and not in the modern sense of that word, but in its old-fashioned definition of cannot be done no matter what—have any true conception of all that infinity is. We cannot because our minds are finite. God’s mind is not. Only an infinite mind can create something from no-thing.

[3] Moreover. If God’s knowledge extends to all things that exist, in whatever way they exist, as we have shown,[4] it follows that He knows not only actual being but also potential being. Now in natural things there is the infinite potentially although not actually, as the Philosopher proves in 3 Phys.[5] Therefore God knows infinite things: even as unity, which is the principle of number, would know infinite species of numbers, if it knew whatever is potentially in it; for unity is every number potentially…

Notes Back to basics. What is potential is not actual (and it takes something actual to turn a potentiality into actuality), but what is potential is unbounded. And since God is the ultimate or first cause of everything, it follows He knows all potentialities, hence He can known infinite things.

[6] Moreover. According to the Philosopher (3 De Anima)[10] an intellect which knows the supremely intelligible knows the less intelligible not less but more: and the reason for this is that the intellect is not corrupted by the excellence of the intelligible, as the sense is, but is the more perfected. Now if we take an infinite number of beings, whether they be of the same species–as an infinite number of men–or of an infinite number of species, even though some or all of them be infinite in quantity, if this were possible; all of them together would be of less infinity than God: since each one and all together would have being confined and limited to a certain species or genus, and thus would be in some way finite: wherefore it would fall short from the infinity of God Who is infinite simply, as we proved above.[11] Since, therefore, God knows Himself perfectly,[12] nothing prevents Him from also knowing that infinite number of things…

Notes We haven’t discussed this topic much, but according to St Thomas that whereas each man belongs to mankind, each angel is its own species. Angels are also immaterial, and thus there is no difficulty in stacking them up from here to forever. Now put you and me together: the sum of our intelligences is not arithmetic, as is obvious from any reading of history. Simply putting more of us together is not going to increase our “joint” mind to infinity. Infinity is infinitely far away. Whereas God is in a different unapproachable class altogether.

[9] Again. Since our intellect is cognizant of the infinite in potentiality, for as much as it is able to multiply the species of numbers indefinitely; if the divine intellect knew not also the infinite in act, it would follow either that our intellect knows more things than the divine intellect knows, or that the divine intellect knows not actually all the things that it knows potentially: and each of these is impossible, as proved above…[15]

Notes The tidbit here is that we can, as any mathematician already knows, be aware of the infinite in potentiality, as admitted in the first note. But a proof that a thing exists does not imply that we understand fully the thing.

[13] From the foregoing it is clear why our intellect knows not the infinite, as the divine intellect does. For our intellect differs from the divine intellect in four respects, which constitute this difference. In the first place, our intellect is simply finite, whereas the divine intellect is infinite. Secondly our intellect knows different things by different species: wherefore it cannot grasp infinite things by one knowledge, as the divine intellect can. The third difference results from the fact that our intellect, since it knows different things by different species, cannot know many things at the same time, so that it cannot know an infinite number of things except by taking them one after the other. Whereas it is not so in the divine intellect, which considers many things simultaneously, as seen by one species. Fourthly, because the divine intellect is about things that are and things that are not, as we proved above.[19]

Notes Ponder this well. Memorize it.


[1] Ch. xlix.
[2] Ch. xlvii.
[3] Ch. xliii.
[4] Cf. ch. l.
[5] iv. seqq.
[6] Ch. xlix.
[7] Ch. xliii.
[8] Ch. xlv.
[9] Ch. xliii.
[10] iv. 5.
[11] Ch. xliii.
[12] Ch. xlvii.
[13] Ch. xlv.
[14] Ch. xlv.
[15] Cf. chs. xvi., xxix.
[16] Ch. xlvi.
[17] 1 Phys. ii. 10.
[18] Ps. cxlvi. 5.
[19] Ch. lxvi.
[20] Cf. ch. lxiii.: The fifth . . . p. 134.
[21] 1 Phys., l.c.
[22] Sum. Th. P. I., Q. xiv., A. 12 ad 1.
[23] Cf. ch. lxvi.

August 9, 2015 | 8 Comments

Summary Against Modern Thought: God Can Read Your Mind

This may be proved in three ways. The first...
This may be proved in three ways. The first…
See the first post in this series for an explanation and guide of our tour of Summa Contra Gentiles. All posts are under the category SAMT.

Previous post.

ESP on a galactic scale? Or, there is no hiding from the Truth.

Chapter 68 That God Knows The Movements Of The Will (alternate translation)

[1] IN the next place we must show that God knows our mind’s thoughts and our secret wills.

[2] For everything, in whatever way it exists, is known by God, in as much as He knows His essence, as we have shown above.[1] Now some things are in the soul, and some in things outside the soul. Wherefore God knows all these differences of things and whatever is contained under them. Now the things in the soul are those that are in our will or our thought. It remains, therefore, that God knows what we have in our thoughts and wills.

Notes The soul, don’t forget, the form of the rational animal man. Your soul is you. It is not material. It cannot be weighed. It exists, therefore, in the mind of God, as it were. We haven’t reached the book or chapter on soul yet, but here is a link to the Summa Theologica.

[3] Moreover. God so knows other things in knowing His essence, as effects are known through their cause being known.[2] Accordingly by knowing His essence God knows all the things to which His causality extends. Now this extends to the works of the intellect and will: for, since every thing acts by its form which gives the thing some kind of being, it follows that the highest source of all being, from which also every form is derived, must be the source of all operation; because the effects of second causes are to be referred in a still higher degree to first causes. Therefore God knows both the thoughts and the affections of the mind.

Notes It may or may not be surprising to you that we always come back to the First Cause. Every here-and-now change needs a first changer or first cause. That’s back in Chapter 13. Though there are any number of secondary causes, since God is the ultimate cause, He must know what He’s up to. Thus He knows what’s in your will and in your intellect.

[4] Again. Even as His being is first and consequently the cause of all being, so His act of intelligence is first, and consequently the cause of all intellectual operation. Wherefore just as God by knowing His being knows the being of everything, so by knowing His act of intelligence and will He knows every thought and will.

Notes Scary, ain’t it? Or rather sobering and plain enough. What’s the line about fear and trembling?

[5] Further. God knows things not only as existing in themselves, but also as existing in their causes, as proved above:[3] for He knows the relation between cause and effect. Now the products of art are in the craftsman through the intellect and will of the craftsman, even as natural things are in their causes through the powers of the causes: for, just as natural things liken their effects to themselves by their active powers, so the craftsman by his intellect gives his handiwork the form whereby it is likened to his art. It is the same with all things done of set purpose. Therefore God knows both our thoughts and our wills.

Notes Man is God’s handiwork. Why? It is a mystery; i.e. a mystery in the theological sense. God did not need to make us, but here we are. To say we’re here because God loves us is merely to rephrase the mystery. I have nothing to offer on this. Others do, and we’ll meet some answers in later chapters.

[6] Again. Intelligible substances are no less known to God than sensible substances are known to Him or to us: since intelligible substances are more knowable, for as much as they are more actual. Now the informations and inclinations of sensible substances are known both to God and to us. Consequently, since the soul’s thought results from its being informed, and since its affection is its inclination towards something–for even the inclination of a natural thing is called its natural appetite–it follows that God knows our secret thoughts and affections…

[8] The dominion which the will exercises over its own acts, and by which it is in its power to will and not to will, removes the determination of the power to one thing, and the violence of a cause acting from without: but it does not exclude the influence of a higher cause from which it has being and action. Thus causality remains in the first cause which is God, in respect of the movements of the will; so that God is able to know them by knowing Himself.

Notes A crude summary: your will decides to act, but the power of your will to make this move is given or caused by God. This power isn’t material, either. How this operation is carried out, nobody knows fully. It is, of course, no argument to say that because nobody understands how it could work that therefore it doesn’t work. That would be like saying airplanes can’t fly because children don’t understand them. We observe the thing to happen. We just don’t understand why, and possibly never will.


[1] Chs. xlix., l.
[2] Ibid.
[3] Ch. lxvi.
[4] Ps. vii. 10.

August 2, 2015 | 17 Comments

Summary Against Modern Thought: Can God Know The Future?

This may be proved in three ways. The first...
This may be proved in three ways. The first…
See the first post in this series for an explanation and guide of our tour of Summa Contra Gentiles. All posts are under the category SAMT.

Previous post.

Does God know everything that will happen? If so, how?

Chapter 65 That God Knows Future Contingent Singulars (alternate translation)

[1] FROM the foregoing it is already somewhat evident that from eternity God has had unerring knowledge of singular contingencies, and that nevertheless they cease not to be contingent.[1]

[2] For contingency is not incompatible with certainty of knowledge except in so far as it is future, and not as it is present. Because a contingency, while future, may not be; so that the knowledge of one who thinks it will be, may be wrong, and it will be wrong if what he thinks will be, will not be. From the moment however that it is, for the time being it cannot not-be: although it may not be in the future, but this affects the contingency, not as present but as future. Hence sense loses nothing of its certainty when it sees that a man is running, although this statement is contingent.

Accordingly all knowledge that bears on a contingency as present, can be certain. Now the vision of the divine intellect from eternity sees each thing that happens in time as though it were present, as we have shown above.[2] Therefore it follows that nothing prevents God having unerring knowledge of contingencies from eternity.

Notes I might have abridged this paragraph but left it to show how careful Thomas was. All the rigor of any modern mathematical theorem. Like I’ve said before, I also enjoy the way our saint eases us into problems.

[3] Again. The contingent differs from the necessary according as each is in its cause: for the contingent is in its cause in such a way that it may not result, or may result therefrom: whereas the necessary cannot but result from its cause. But according as each of them is in itself, they differ not as to being, on which the true is founded: because there is not in the contingent, considered as it is in itself, being and not-being, but only being, although it is possible for the contingent not to be in the future. Now the divine intellect knows things from eternity, not only as to the being which they have in their causes, but also as to the being which they have in themselves.[3] Therefore nothing prevents it having eternal and unerring knowledge of contingencies.

Notes Don’t forget that eternal does not mean “starting at some point in the dim and forgotten past and looking forward into the misty future” but instead as “outside of time.” The analogy, imperfect as all analogies are, is looking down from on high onto the timeline of history.

[4] Moreover. Even as the effect follows certainly from a necessary cause, so does it from a complete contingent cause unless it be hindered. Now, since God knows all things, as was proved above,[4] He knows not only the causes of contingencies, but also that which may possibly hinder them. Therefore He knows certainly whether contingencies be or not.

[5] Again. An effect does not happen to exceed its cause; but sometimes it falls short of it. Hence, since in us knowledge is caused from things, it happens at times that we know necessary things, by way not of necessity but of probability. Now, just as with us things are the cause of knowledge, so the divine knowledge is the cause of the things known.[5] Nothing therefore prevents things whereof God has necessary knowledge being contingent in themselves.

Notes Oho! A shout-out to probabilists and statisticians from the man himself. Not only that, he ties, as we should but don’t, probability to knowledge of causes. That point is subtle, so I’ll leave off here. But stick around. Next week I’ll have a paper on this topic.

[6] Further. An effect cannot be necessary if its cause be contingent, for it would follow that an effect exists after its cause has been removed. Now the ultimate effect has both a proximate and a remote cause. Hence if the proximate cause be contingent, its effect must needs be contingent, even though the remote cause be necessary: thus plants do not necessarily bear fruit–although the motion of the sun is necessary–on account of the contingent intermediate causes. But God’s knowledge, although it is the cause of the things it knows, is nevertheless their remote cause. Wherefore the contingency of the things it knows does not militate with its necessity: since it happens that the intermediate causes are contingent.

Notes Never forget we already know God is the first necessary cause of all.

[7] Again. God’s knowledge would not be true and perfect, if things happened not in the same way as God knows them to happen. Now God, since He is cognizant of all being, whereof He is the source, knows each effect not only in itself, but also in its relation to every one of its causes. But the relation of contingencies to their proximate causes, is, that they result from them contingently. Therefore God knows that certain things happen and that they happen contingently. Wherefore the certainty and truth of the divine knowledge do not take away the contingency of things.

Notes This immediately follows. The big step comes next.

[8] It is therefore clear from what has been said how we are to refute the objection[6] gainsaying God’s knowledge of contingencies. For change in that which is subsequent does not argue changeableness in that which precedes: since it happens that contingent ultimate effects result from necessary first causes. Now the things known to God do not precede His knowledge, as is the case with us, but are subsequent thereto. Therefore it does not follow that, if what is known to God be changeable, His knowledge can err or in any way be changeable. It will therefore be a fallacy of consequence if, because our knowledge of changeable things is changeable, we think that this happens in all knowledge…

Notes And here we see that Pinnock (see last week) and others cannot be right that God can be “surprised” by future events. The future is not “open” in this sense. It is an understandable error to fall into, however. We’re dealing with infinities such as God’s omniscience and omnipotence, which St Thomas was careful in the beginning to say that we could never know. We’re always coming at God on the edges, so to speak. We can never grasp what it’s like out at infinity.

Therefore, “problems”—or, as the Church calls them, mysteries—like the compatibility of free will with an all-powerful all-knowing God cannot be solved by us in any complete sense. The best we can do is create analogical arguments, or even, in some cases, formal technical proofs of associated ideas, but a full understanding must elude us. The best books on this subject are by William Lane Craig: The Only Wise God: The Compatibility of Divine Foreknowledge & Human Freedom, and The Problem of Divine Foreknowledge and Future Contingents from Aristotle to Suarez, and a few others. The first is a semi-popular treatment, and the second an expert treatise. When I get around to it, I’ll review the first.


[1] Cf. ch. lxiv.
[2] Ch. lxvi.
[3] Ch. lxvi.
[4] Ch. l.
[5] Cf. ch. lxv.
[6] Cf. ch. lxiii.: The third . . . p. 133.

July 19, 2015 | 8 Comments

Summary Against Modern Thought: Can God Know Things That Aren’t?

This may be proved in three ways. The first...
This may be proved in three ways. The first…
See the first post in this series for an explanation and guide of our tour of Summa Contra Gentiles. All posts are under the category SAMT.

Previous post.

Some simple arguments showing God knows both singulars and things that are not. I don’t think there will any dispute about the contentions, so in the Notes we do a little wandering. Next week is more controversial material.

Chapter 65 That God Knows Singulars (alternate translation)

[2] …For it has been shown[1] that God knows other things in as much as He is their cause. Now God’s effects are singular things: because God causes things in the same way as He makes them to be actual; and universals are not subsistent, but have their being only in singulars, as is proved in 7 Metaph.[2] Therefore God knows things other than Himself not only in the universal but also in the singular.

Notes In re “universals are not subsistent”. St Thomas means universals don’t exist actually as some ideal to which singulars are compared. Plato’s forms are not real. We are Aristotelians here.

[4] …Moreover. The nature of a genus cannot be known perfectly unless its first differences and proper passions be known: thus the nature of number would not be perfectly known if odd and even were unknown. Now universal and singular are differences or proper passions of being. Therefore if God, in knowing His essence, knows perfectly the common nature of being, it follows that He knows perfectly the universal and the singular. But, just as He would not know the universal perfectly, if He knew the intention of universality without knowing the thing in the universal, such as man or animal, so too He would not know the singular perfectly if He knew the nature of singularity without knowing this or that singular thing. Therefore God must needs know singulars.

Notes Like we said last week, there is little—really, no—dispute that God knows singulars, and these proofs are therefore adequate. The tidbit to note here is about numbers. Two points. The first is what we might call the commoner’s fallacy, which might also be called the we-now-know fallacy, and which is the practice whereby anything that is known by one of us (human beings) it is therefore knowledge for or of all of us, knowledge any of us might claim to know. As Wilhelmsen says in his delightful Man’s Knowledge of Reality: An Introduction to Thomistic Epistemology, “What is the difference between a master sergeant reading the Articles of War to a company of recruits and a lawyer citing the same in a court-martial?”

So just because there may be some person out there who knows all about the nature of number—and this is the second point—that knowledge does not belong to you or me, too by default. Plus, as much knowledge about numbers that exists among us, it’s unlikely anybody knows all about the nature of number. Readers who are mathematicians will probably agree with this.

[1] Ch. xlix.
[2] D. 6. xiii., xiv.

Chapter 66 That God Knows Things That Are Not (alternate translation)

[1] In the next place we must show that God lacks not the knowledge of things that are not.

[3] …Again. The knowledge of God’s intellect stands in the same relation to other things as the knowledge of a craftsman to the works of his craft: since He is cause of things by His knowledge.[3] Now the craftsman by the knowledge of his art knows even those things which are not yet produced by his art: since the forms of his art pass from his knowledge into external matter so as to produce the works of his art: and consequently nothing prevents forms which have not yet materialized outwardly from being in the craftsman’s knowledge. Therefore nothing prevents God from having knowledge of things that are not.

[5] …Moreover. Our intellect, in respect of the operation by which it knows what a thing is, can have knowledge of those things also that are not actually: since it is able to comprehend the essence of a lion or horse, even if all such animals were slain. Now the divine intellect knows, as one who knows what a thing is, not only definitions but also enunciations, as shown above.[7] Therefore it can have knowledge of those things also that are not.

Notes The difficulty here is that we had to have some experience of actual lions or horses before we can know what they were like would they were all gone. Think dinosaurs.

[6] Again. An effect can be foreknown in its cause even before it exist: even so an astronomer foreknows a future eclipse by observing the order of the heavenly movements. Now God’s knowledge is of all things through their cause: for by knowing Himself, Who is the cause of all, He knows other things as His effects, as we proved above.[8] Nothing, therefore, prevents Him from knowing those things also that are not yet.

Notes Predictions, like all probability and all statements of logic, are conditional. As long as we grasp the conditions, the deductions follow, and we can know them. But some predicitons (as regular readers know) are probabilitistic. Given the normal conditions, the probability of a head in a coin flip is 1/2. We know this 1/2 and not the outcome; but this is still knowledge (in the strong sense of that word).

And now another tidbit for our mathematical friends (only the first part of the argument is given).

[7] Moreover. There is no succession in God’s act of understanding, any more than there is in His existence.[9] Hence it is all at once everlasting, which belongs to the essence of eternity,[10] whereas the duration of time is drawn out by the succession of before and after. Wherefore the proportion of eternity to the whole duration of time is as the proportion of the indivisible to the continuous, not indeed of the indivisible that is the term of the continuous, and is not present to each part of the continuous—for such is likened to an instant of time—but of the indivisible that is outside the continuous, and yet synchronizes with each part of the continuous, or with each point of a signate continuous: because, since time does not exceed movement, eternity, being utterly outside movement, is altogether outside time…

Notes Math can be done without symbols! Although symbols are eminently useful, they do tend to tempt one into the Deadly Sin of Reification.

[8] By these arguments it is made clear that God has knowledge of not-beings. Nevertheless not-beings have not all the same relation to His knowledge. For those things which neither are, nor shall be, nor have been, are known by God as possible to His power. Wherefore He knows them, not as existing in themselves in any way, but as merely existing in the divine power. Such things are said by some to be known to God according to His knowledge of simple intelligence.

Notes Even God can imagine. That’s enough for us. I don’t think there is any dispute, used as we are to mathematical-like proofs, that God knows singulars or things that are not. Next week we ask whether God knows future contingents, which is a juicier question.

[1] Ch. lxi.
[2] Categ. v. 18.
[3] Bk. II., xxiv. See above, ch. lxv.: Moreover. God’s intellect . . . p. 137.
[4] Chs. xlix., liv.
[5] Ch. xliii.
[6] Ch. xlvii.
[7] Chs. lviii., lix.
[8] Ch. xlix.
[9] Ch. xlv.
[10] Ch. xv.