Commentaria in Summam contra Gentiles, Liber I

The third conclusion, answering the third objection, is: God has had infallible knowledge of singular contingents from eternity, and yet contingents do not cease to be ¹. Concerning this conclusion Saint Thomas does three things: first, he confirms it with reasons; second, he responds to the objection brought forward ²; third, he corroborates the proposition with authorities ³.

I. As to the first point, two things must be noted in the conclusion. First, that mention is made of singular contingents. For that God knows contingents with respect to their universal natures involves no difficulty: since universals themselves possess a certain necessity and immutability, and so can be subjected to certain knowledge. But that He knows singulars is not without considerable doubt, on account of their mutability, from which it seems they cannot be subjected to a certain and infallible knowledge, such as divine knowledge is. On this account, in order to show that St. Thomas intends to remove every difficulty, he assumes in the conclusion both what pertains to the divine science and what pertains to contingency, saying that God has infallible knowledge of these things, not fallible and uncertain knowledge as we do, from eternity. In this it is intimated that He knows them before they exist, and yet they do not cease to be contingent: that is, from the fact that they are thus known by God, their contingency and mutability are not taken away from them, as some wish to persuade; rather, the certainty of the divine science and the contingency of things stand together at once.

II. The conclusion is therefore proved first as follows ⁴. The intuitive gaze of the divine intellect is borne from eternity upon each of those things that are accomplished in the course of time, insofar as it is present, as was shown above. Therefore nothing prevents God from having infallible knowledge of contingents from eternity. — The consequence is proved: because every cognition that is borne above a contingent thing insofar as it is present can be certain.

To clarify this point, Saint Thomas notes that the contingent is not incompatible with the certainty of knowledge except insofar as it is future: for, since it may fail to occur, one who judges it to be future can be mistaken. But insofar as it is present, it can be known with certainty: for at that moment it cannot not be, although in the future it may not be; and this already pertains to the contingent as future. Hence the sense is certain when seeing a man running, even though what I say, that the man is running, is contingent.

Concerning that assumption offered in proof of the consequence, note that Saint Thomas says that cognition which is directed to the contingent as present can be certain, but is not absolutely certain. For it is not necessary that such cognition be certain: the senses, indeed, can be deceived about common sensibles that are present, and even about proper sensibles per accidens. Yet nevertheless, although it need not be certain, it does not conflict with such cognition, as being a cognition of a thing present, that it be certain: since the very thing that is present can be known with certainty. And therefore that cognition in which error cannot occur of itself can be borne with certainty to the contingent as present: namely because, insofar as the contingent itself is concerned, there is nothing repugnant in its being knowable with certainty as it is present.

2. Concerning the assigned difference between the contingent as it is future and as it is present, it must be considered, according to the doctrine of Saint Thomas in Verit., q. II, a. 12, that if some cognition is altogether certain, such that falsity cannot exist in it, the knowable object must never fail to be what is known of it; for if it did fail, the cognition itself would follow as false, just as if I judged that Socrates is sitting and he were not sitting, I would know something false. And therefore it is necessary that such a thing as is known possess in itself a certain necessity. But the contingent, so long as it is future, has no necessity, since it can be impeded from coming about, and thus can be non-existent. Yet when it is already present, and no longer future, it has necessity, and cannot be impeded from being for that time for which it is, and consequently for then it cannot not be — because whatever is, when it is, must necessarily be, as is said in I Perihermenias ⁵. Therefore, as future, it cannot be subject to certain cognition, but very well as present.

Yet it must be noted that knowing the contingent as future can be understood in two ways: in one way, insofar as the mode of futurity holds on the side of esse that belongs to a thing in its cause; in another way, insofar as it holds on the side of the esse of the effect in itself. On the side of the cause, to know the contingent as future is to know that the cause is disposed to its production. On the side of the effect, however, it is to know that the effect itself will be, and that it will at some time be true to say this is, once it has been demonstrated. These two kinds of knowledge differ greatly, just as being disposed to produce something and its actually being future at some time differ greatly. For sometimes a cause may be disposed to the production of some effect, and yet that effect will never come about; hence Aristotle says in De Generatione II ⁶ that one who is going to walk will not walk. Therefore what is said, namely that the contingent as future cannot be subject to certain knowledge, must be understood in the second way, not the first. For it cannot be judged with certainty that it will be; but that the cause is disposed to its production can certainly be known, because this has a kind of necessity; for for the time for which the cause is disposed to the production of its effect, it cannot fail to be so disposed, just as it was said of the present effect that for that time it cannot not be.

3. Concerning that proposition, A contingent thing, as present at that time, cannot not be, it should be noted that the phrase at that time can determine the words cannot, and can determine the words not be.

If in the first way, then it would be false, nor is it an object of the understanding for Saint Thomas. For the sense is that a contingent thing, at the time at which it exists, does not have the potency not to be. Which is false: since it is corruptible, and can be non-existent at another time, and absolutely even at that time non-existent.

In the second way, the sense is that a contingent thing existing in the present does not have the power not to be, at that time, in the state it is in. This can be understood in two ways: one way concerns absolute possibility; the other, possibility of mutability. If it concerns absolute possibility, then it is true in the composite sense: for this proposition, a contingent thing, as presently existing, is not, is impossible. But in the divided sense it is false, and its opposite is true: for, with Socrates demonstrated as existing, it is true to say, this one can at this time not be, since it is not of the essence of Socrates considered absolutely that he be at this time, but it is indeed of his essence as existing for this time. — If, however, it concerns the possibility of mutability, then it is true in both senses. For what is present for some time cannot, within that time, be changed from being present to being not present.

Likewise, the proposition of the Philosopher, Whatever is, when it is, must necessarily be ⁷, is to be distinguished just as the preceding one.

Saint Thomas therefore understands his proposition in the second sense, and in the composite sense. For this reason he added that it can in the future not be, and that this already pertains to the future: namely because, although the present, as present, cannot not be in the time in which it is present, it nevertheless has the power not to be in a future time; for with respect to future time, say tomorrow, it has the power to be or not to be, and thus has the character of the future.

III. But there are two points that seem to present a difficulty. The first is that a contingent future cannot be subject to certain knowledge. For Durandus argues against this ⁸: just as from a necessary cause its proper effect follows infallibly, so too from an impeding-able cause not impeded. But, once the necessary cause is known, its effect is known with certainty on account of the infallibility of the production of the effect. Therefore also, once an impeding-able cause is known, together with all the things that could impede it and the fact that it will not be impeded, its effect can be known with certainty. But someone, say God, can know this. Therefore a contingent as future can be known with certainty.

It is also argued by Aureol's argument ⁹. God knows with certainty that the Antichrist will be. But this is to know a contingent as future. Therefore the contingent as future is subject to certain knowledge.

2. The second is that God knows the contingent as it is present ¹⁰. Against this Aureol argues ¹¹: If this is so, it follows that the contingent is from eternity present in itself, which is false. The consequence is proved thus: just as from a cognition attaining a thing as past, it is inferred that the thing was; and from a cognition attaining a thing as future, it is inferred that the thing will be; so from a cognition attaining a thing as present in itself, it is inferred that the thing is present in itself. For the following holds: I saw Socrates sitting, therefore Socrates sat; I shall see Socrates sitting, therefore Socrates will sit; I see Socrates sitting, therefore Socrates sits. If, then, God sees the contingent from eternity as present, it follows that it is from eternity in its own presence in itself, not merely in the cognition of the knower.

IV. To the first argument against the first proposition, it is said that two things are touched upon in the proposition of Saint Thomas: namely, that the thing known be contingent, and that it be future. Whichever of these is lacking, the effect can be known with certainty. For if the effect has necessity in its cause, however future it may be, it can be known with certainty: because in its cause it has determination and immutability, as a future eclipse. If also it does not have necessity in its cause but contingency, if it is considered as present, since it is already determined and outside its cause, it can be subjected to certain cognition. It is said, therefore, that an effect existing in its cause absolutely incapable of being impeded, considered in no way impeded, neither before its production nor in the very production itself, does not have the character of the contingent as such, but of a necessary effect: because an effect is then only said to have contingency in its cause when the cause can be impeded. Therefore, if it is considered as in its cause with all things removed that could impede it, it is considered as having necessity in its cause, not contingency, especially speaking of causes acting naturally: for a cause is that to which the effect necessarily follows once impediments are removed. And to know the contingent in this way is not to know the contingent as contingent is, but as necessary. But Saint Thomas speaks of the contingent as contingent is in its cause, not as it has necessity in it: because then even as future it can be known with certainty. — This response can be had from the third reason to be adduced below ¹²

Another way of saying it is also possible: namely, that the contingent is then not known as future, but as present. For a cause cannot be known with certainty to be in no way impeded from the production of its effect except when it is known, up to and including the very production of the effect itself, that it is not impeded: for in any preceding instant it can be impeded. And thus the effect is known as present.

2. To the second ¹³ it is said that the word ut placed in the consequent can be understood in two ways: first, as signifying a condition known about the thing; second, as signifying the ground of certainty on the side of the thing known. In the first way, the sense is that God, in knowing that the Antichrist will be, knows the future being of the Antichrist, and not only the Antichrist. — In the second way, the sense is that the reason why the future thing itself is known with certainty is its very future being, or because it is known in its cause.

If it is taken in the first way, then the consequent can likewise be understood in two ways. In one way, by taking the condition in relation to God as knower. And thus the minor is denied. For in order that something be known as future by a knower, it does not suffice that a proposition about the future be known; rather, according to the doctrine of St. Thomas, Verit., q. II, a. 12, there is required between the knowledge of the knower and the event of the thing an order of present to future. But the order of the divine cognition to a contingent thing is not of this kind; rather, it is an order of present to present, as appeared above ¹⁴. — In the other way, by taking that condition in relation to us. And thus the minor and the whole argument are conceded: but it is not argued against what we intend. For we do not intend that a thing cannot be known with certainty to have this condition, namely that it be future: but that from the fact that it is known as future, it does not follow that it can be known with certainty.

But if it is taken in the second way, then indeed it is against the intent, but the minor is denied. For although God knows that Antichrist will be with certainty, the reason for this certainty on the side of the thing known is that he sees it in its own presence, not because he knows it in its cause, in the way in which it is said to be known as future to us. For if he knew it only as it is in its causes, and did not know it as present in itself, he would not know with certainty the proposition Antichrist will be.

V. To the argument against the second proposition ¹⁵ he answers, in accordance with what was said in the preceding chapter, that a thing can be known as present in two ways. In one way, because it is attained as present according to the time by which that cognition itself is measured. And then it is true that from such a cognition it can be inferred absolutely that the thing is in itself: just as from the cognition by which something is attained as past, it is inferred that it was. — In another way, because it is attained as present according to some present measure superior to time, in which both the very existence of the thing and the time not yet existing in which it will at some point be true to say this is are contained. And then it is denied that from such a cognition it can be inferred that the thing is absolutely: because such a cognition is terminated at the thing as present, not according to the time present to us, but according to eternity and according to the time future to us as it itself is in eternity. Now when it is said absolutely that is, it is signified that it has esse in the time present to us, as was shown above ¹⁶. Now, we have said that God knows future things as present in their actuality, not indeed in the time present to us, but in eternity, and in the time future to us insofar as it too is contained in eternity. Therefore it does not follow that from his cognition it is inferred that future things already are.

VI. Second ¹⁷. Things are known by God according to the esse they have in themselves. Therefore, etc. — The consequence is proved. Because a contingent thing, insofar as it is in itself, does not differ from a necessary one with respect to esse, upon which truth is founded, although it differs from it insofar as each is considered in its cause. But a necessary thing can be known infallibly. Therefore also a contingent thing, in this way.

For the declaration of what is brought forward in this place, it must be considered that a necessary effect, and also a contingent one, has both that it is a thing and a certain nature in itself, and that it is an effect. In the first way it is said absolutely; in the second way it bears an order to its cause. Thus, therefore, we can consider necessity and contingency in these in two ways: namely, absolutely, insofar as they are certain natures; and insofar as they are effects, that is, according to their order to the cause.

If they are considered absolutely and in themselves, that thing is called necessary which, as far as its own nature is concerned, cannot fail nor can fail to be: just as we say the heavenly bodies are necessary beings. But that is called contingent which, as far as the condition of its own nature goes, can fail and not be; this is also called a possible and corruptible thing: such as Socrates and his sitting. And this necessity and contingency is intrinsic and essential to the thing, and is never removed from the thing: for in whatever state a contingent thing is placed, it is always contingent and never intrinsically necessary; and a necessary thing is always necessary and never contingent.

If, however, it is considered under the aspect of an effect, or in relation to its cause, that effect is called necessary which proceeds from a cause acting necessarily and which cannot be impeded. But that effect is called contingent which is naturally apt to proceed from a cause that can be impeded; and consequently, although at times the cause may be inclined toward its production, it can nevertheless fail to occur. Now this effect, considered under the aspect of an effect and in relation to its cause, can be regarded in two ways: namely, with respect to the nature of the effect as effect; and with respect to the mode of being it has. If it is considered with respect to the nature of the effect as effect, contingency always belongs to it: for however a contingent effect may have being, it is always a contingent effect, that is, always the effect of an impedinable cause. If, however, it is considered with respect to its mode of being, then it is at times contingent and at times necessary. For insofar as it exists virtually in its cause and has not yet been produced, it is contingent: because, as such, it can be and not be. But insofar as it has esse in act in itself, as already produced outside its cause, it is necessary: because it has already been determined to esse, and cannot for that time during which it is, not be.

2. This is therefore what Saint Thomas says, since the contingent differs from the necessary according as each is in its cause, but not according to what each of these is in itself: not because the nature of the contingent is changed into the necessary, either as the thing is or as it is an effect; but because the mode of being is changed, and according to one mode contingency belongs to it, according to the other necessity. For according as it is in its cause, contingency belongs to it: and in this it differs from the necessary, because the necessary, even according as it is in its cause, has the mode of necessity, in that it cannot fail to be produced; but the contingent, according as it is in its cause, has the mode of contingency, because it can be impeded from being produced. But according as it is in itself, necessity belongs to it: and in this it does not differ from the necessary, because, just as a necessary effect, as existing in itself, is determined to esse and cannot not be, so too a contingent effect, according to that mode, is determined to esse and for that time cannot not be, although it can in the future not be. And because the truth of cognition and of enunciation is founded upon the esse of a thing, or accompanies the very esse of the thing, therefore from this it arises that of a contingent effect, when it is in itself, it can be said determinately and truly that it is, just as of the necessary: for while Socrates is running, it can be said as truly that Socrates runs, as of an eclipse existing that the eclipse is. But according as each is considered as future, namely according as it is virtually in its cause, it cannot similarly be said determinately and affirmatively of each that it will be: for of the eclipse it can be said determinately that it will be, but not of Socrates that he will run. And this is what Saint Thomas signified when he said that the contingent, according as it is in itself, does not differ from the necessary with respect to esse, upon which the true is founded: because namely it is so determined for that time with respect to esse as the necessary is; and consequently it can be known with certainty and determinately, and truly enunciated, just as the necessary.

3. Finally, it must be noted that this argument differs from the first: for the latter proceeds from the presence of the thing, whereas this one proceeds from necessity, or from a difference from what is necessary; although from one the other follows. Hence this argument is a confirmation of the preceding one.

VII. Third. God knows not only the causes of contingent things, but also those things by which they can be impeded: namely, by knowing that they will impede or will not impede. Therefore, and so on. — The consequence is proved. Because, just as from a necessary cause the effect follows with certainty, so too from a complete contingent cause if it is not impeded.

Note, as was said in the first reply to Durandus's objection ¹⁸, that this knowledge by which contingent causes are known, and that they are not impeded or are impeded, is not knowledge of the contingent as it is contingent, but as it has necessity. And it is understood of the effect of natural causes. For perhaps with respect to the effects of the will, knowledge of the causes and impediments does not suffice for certainty of knowledge unless the cause itself be known as actually ultimately operating without impediment—which is to know the effect as it already exists in its esse, and not merely as it exists in its causes.

Fourth. Just as things are for us the cause of knowledge, so conversely God's knowledge is the cause of things. But we sometimes know necessary things not only necessarily but also probably. Therefore contingent things can also be known by God, and yet the knowledge concerning them be held as necessary. — The minor is proved. Because, although an effect cannot attain to the perfection of its cause, it sometimes nevertheless falls short of it.

VIII. Fifth ¹⁹. If knowledge of such things were denied to God, this would be chiefly because the science of God is the cause of the things known, and is necessary, whereas from a necessary cause no contingent effect proceeds. But this is no obstacle. For the science of God is a remote cause, not a proximate one. And although the remote cause be necessary, yet if the proximate cause is contingent, the effect will be contingent: otherwise it would follow that the effect depends on the remote cause alone. For we see that plants do not bear fruit necessarily, although the motion of the sun is necessary, on account of the intervening contingent causes.

2. Concerning this argument there are two things that create a difficulty. The first is that God's knowledge of contingent things is a necessary cause. The second is that although the effect's contingency stands together with its necessity, because it is a remote cause, not a proximate one.

Against the first point it is doubted ²⁰: because knowledge is taken either under the aspect of knowledge or under the aspect of cause. If under the aspect of knowledge, it seems that it is not necessary, thus. The act of the divine will concerning contingents is not necessary. Therefore neither is the act of divine cognition. — The antecedent is evident, because otherwise God would will the existences of creatures by a necessity of nature and not freely. — The consequence is also evident, because a contingent thing is not knowable in advance to be going to be before it is willed to be going to be. If under the aspect of cause, it is likewise argued that it is not a necessary cause. The knowledge of God is necessary. Therefore it cannot be but that its effect come about; for this belongs to the character of a necessary cause. Therefore its effect is not contingent. And so the contingency of the effect does not stand together with the necessity of the divine knowledge. The opposite of this is asserted here.

3. Against the second position, it is argued with the reasons of Scotus, I Sent., d. xxxix ²¹ First, because all things will be necessary. — The consequence is proved. A moving cause, insofar as it is moved, if it is moved necessarily, moves necessarily. But every second cause moves insofar as it is moved by the first. Therefore, if it is moved necessarily by the first, it too will move necessarily. And thus every effect will be necessary.

Second. A prior cause naturally regards its effect prior to the posterior cause. Therefore, in that prior cause, if it has a necessary relation to the effect itself, it will give it necessary esse. Therefore, the second cause will not be able to give it contingent esse.

Third. Whatever is produced by posterior causes can be produced immediately by the first cause. And then it would have the same entity as before, and would be contingent just as it is now. Therefore it has its contingency now from the first cause, and not only from the proximate cause.

*Fourth. God has produced many things immediately and does produce them, and yet all contingently. Therefore etc. *

IX. To make the first difficulty evident, it must first be considered that here we are not speaking of knowledge with respect to its entity, for since it is identical with the divine essence, it is certain that its entity is necessary; rather, we speak of it insofar as it signifies an order to a contingent object known: whether this be the order of knowledge, inasmuch as it is knowledge, to the thing known inasmuch as it is known; or the order of knowledge, inasmuch as it is a cause, to the thing known inasmuch as it is its effect. And we speak of the knowledge of vision, not of the knowledge of simple intelligence, which is admittedly prior by reason to the act of the will and altogether necessary, as is said in Prima, q. 19, a. 3, ad 6.

It must be considered, secondly ²², that divine knowledge, insofar as it is knowledge, can be understood to be necessary in two ways: namely, either with absolute necessity or with the necessity of immutability. If we speak of absolute necessity, in this way it is not necessary; for that is said to be absolutely necessary with which, speaking absolutely, it is repugnant to be otherwise, just as we say that man is necessarily a rational animal, because it is repugnant to man not to be a rational animal. But whatever God knows by the knowledge of vision, it is not absolutely repugnant for God not to know it; for just as from eternity He determined that it would be—say, the Antichrist—so from eternity He could have determined that the Antichrist would not be, since He is not necessitated to will the esse of a creature; and therefore, just as from eternity He knew that he would be, so He could have known from eternity that he would not be, for the knowledge of vision follows upon the determination of the divine will. — But if we speak of the necessity of immutability, in this way it is necessary; for what He knew from eternity would be, He always knows, and it cannot be changed so that He knows first and afterwards does not know, as happens with our knowledge.

X. Yet it must be noted that St. Thomas sometimes says of this antecedent, that God knew this to be future, that it is absolutely necessary ²³, and this because absolutely necessary can be taken in two ways. In one way, for what is necessary from the very meanings of its terms, so that its opposite is impossible, as involving a contradiction from the terms themselves: as that man is a rational animal. — In another way, for what is necessary in itself, not merely with respect to a dependence upon another proposition: and thus a proposition is said to be absolutely necessary whose proper signification is necessary. But what is necessary only by dependence upon another proposition is that whose signification is not necessary, but only its order to something else is necessary: as in this conditional, If Socrates runs, Socrates is moved, the consequent is necessary with the necessity of consequence only, namely with respect to its order of dependence upon the antecedent, but not with respect to its own signification. The absolutely necessary, taken in this way, is more common than the absolutely necessary taken in the first way: for it contains under itself both that which is absolutely necessary, and that which is necessary with the necessity of immutability.

Since, then, in that antecedent there can be a twofold necessity—namely, the necessity of the consequence, or of its order to some antecedent, and the necessity of what is signified in itself—Saint Thomas determined the mode of this necessity, saying that it is necessary absolutely, as if to say: In this conditional, If God knew something to be future, it will be, the antecedent is not only necessary by the necessity of inference from some antecedent, that is, as if it necessarily followed from some antecedent, but it is also necessary in itself, that is, according to its own proper signification. For it is necessary by the necessity of immutability, because what is true cannot be changed into falsehood. Hence also at the end of this chapter he calls the same thing necessary absolutely and necessary by the necessity of the consequent. And thus it is clear that there is no contradiction between what the said Saint Thomas says and what we have said.

2. From these things is shown the error of those who say that Saint Thomas, in that antecedent, understands absolute necessity in the first way. For they say that he takes the absolutely necessary to be that whose opposite is simply impossible; and that he speaks of God's knowledge not in itself, but as signified by a verb of past tense, as when we say, God knew this. For although God's knowledge of contingents is not absolutely necessary, yet this proposition, God knew this, is absolutely necessary: because it concerns the past; and a proposition about the past is absolutely necessary, and its contradictory is simply impossible, even by divine power.

This opinion, in respect of its three parts, assumes something false. For it is false that St. Thomas does not speak of God's knowledge in itself, but only as signified by a verb of past tense; indeed, he makes no distinction between God's knowledge in itself and that knowledge as signified in the past. — It is also false that he speaks of the necessary in the first way absolutely. — And it is false that every proposition about the past is absolutely necessary, such that its contradictory is simply impossible.

The first of these is clear from I Sent., d. XXXVIII, a. ult., ad 4. For there Saint Thomas says that that antecedent is absolutely necessary, both from the immobility of the divine act and from its ordination to the thing known, because God's knowledge is terminated to a thing as it is in itself. Here it is evident that he is speaking of God's knowledge in itself, not as signified by a verb in the past tense: for those conditions belong to God's knowledge in itself, not as it is signified.

According to the second esse, it is false, as is clear from what has been said. For St. Thomas, in the First Part, Question Verit.²⁴, holds that this consequent, this will be, is likewise absolutely necessary just as the antecedent is. But no one would say that this consequent is necessary in that first way, absolutely: rather, St. Thomas, in the First Part²⁵, explains the ground of its necessity, because everything that is, when it is, must necessarily be; which is clearly necessary not absolutely, but immutably for the same now.

The third is also shown to be false, both in itself and according to Saint Thomas. In itself, indeed, because I take this true proposition about the past, Adam was, and argue thus. God, speaking absolutely, could have not produced Adam: for he produced him freely. Therefore this proposition, Adam is, could never have been true. Therefore also that proposition about the past, which presupposes the one about the present, could have been untrue. Therefore its opposite could have been true, namely, Adam was not. Therefore this proposition, Adam was, is not absolutely necessary, as if, namely, its opposite implied a contradiction. Therefore not every proposition about the past is in that way absolutely necessary. — That it is false also according to Saint Thomas is evident from what he says in Verit., q. XXIII, a. 4. For there, ad 4, he says that God's having willed something, after he has willed it, is necessary ex suppositione, just as Socrates' having run, after he has run. But it is manifest that these are propositions about the past. Therefore etc. — But it is true that, by implying pastness in a past thing, the proposition is absolutely necessary: as if I were to say, Adam past was, in the composite sense.

XI. It must be considered, thirdly²⁶, that knowledge, insofar as it is a cause, may be said to be necessary in two ways: in one way, on the side of the cause in itself; in another way, on the side of the production of the effect. In the first way, a cause is called necessary when the disposition by which it is productive of the effect, and which is the foundation of its relation to the effect as to something producible, is necessary in itself and cannot be otherwise: in the way in which we say that the motion of the sun is a necessary cause, because it cannot not be (according, namely, to the opinion of the philosophers). In the second way, a cause is called necessary when it cannot fail to produce its effect: as we say that the motion of the spheres is a necessary cause of the eclipse of the sun or the moon. In both ways the divine knowledge is a necessary cause of the things known: namely, because it cannot not be; and because it cannot be impeded so that the effect of the divine knowledge should not come about, in the manner in which it has been ordained by that knowledge to come about.

It must be noted, however, that since there is a twofold necessity—namely, absolute necessity, and necessity ex suppositione and also from the necessity of immutability—the divine science is not to be understood as necessary in itself on the side of the cause and on the side of the dependence of the effect, as though there were in these an absolute necessity. For this is not true according to the mind of Saint Thomas: with him, the science of vision could have not existed from eternity, just as God could have from eternity not determined the production of creatures; similarly, effects proceed freely from it, since God could have determined from eternity that they should not come about. But it is understood of the necessity of supposition and immutability. For, given that in God's science it is so that a certain effect will come about, it cannot be prevented from coming about. This is not found in secondary contingent causes: for such a cause may be disposed to the production of an effect, and yet be prevented from its actual production. And likewise, given that God has knowledge of certain things as to be produced, He cannot change so as not to have it.

XII. These suppositions being granted, in answer to the doubt raised against the first proposition²⁷ it is replied that this discourse concerns the knowledge of God insofar as it bears the relation of cause to what is caused. Nevertheless, in both ways it is necessary in some manner, as we have shown.

When it is first objected that necessity has no place in the nature of science, the answer is given that the act of the divine will with respect to contingents, although not necessary absolutely, is nevertheless necessary by the necessity of immutability, in the way in which we said that the science of vision is necessary.

But when it is objected that it is not necessary even in the order of cause, it is said first that in the way in which a cause is necessary, its effect cannot fail to come about. For if it is necessary absolutely, it cannot be absolutely otherwise than that the effect come about; but if it is necessary ex suppositione, it cannot be, given the supposition, otherwise than that the effect come about. Now it has been said that God's knowledge is necessary not absolutely, but ex suppositione. Therefore it does not follow that its effect cannot not be, except given the supposition. But when it is inferred, Therefore it is not contingent, the consequence is denied: for necessity ex suppositione does not remove contingency; for Socrates' sitting is absolutely contingent, and yet it is necessary given the supposition that he sits.

It is said second that, when the cause exists necessarily, it cannot be that its effect does not occur in the manner in which it is its effect.* For if it is its effect with respect to the esse of the thing absolutely, it cannot be that its effect does not occur with respect to the esse considered absolutely; but if it is its effect with respect to the esse together with the mode of contingency and necessity, it cannot be that it does not occur according to that mode.* Now God's knowledge is the cause of things with respect to both esse and mode. Therefore it cannot be that the effect which is in God's knowledge as occurring necessarily does not occur necessarily; and it cannot be that the effect which is in God's knowledge as occurring contingently does not occur contingently. It is clear, moreover, that by this the contingency of the effect is not removed; rather, it is established.

XIII. For the clarification of the second doubt²⁸, we must first consider, from the doctrine of Saint Thomas in the place cited above²⁹ and in Verit., q. II, a. 14, that, since for the esse of an effect dependent on several causes ordered together each cause is required, the failure of either introduces failure in the effect. And therefore, whether the first cause is contingent or the second, the effect will be contingent; but if one of them is necessary, the effect will not on that account be necessary. For the failure of anything required for esse introduces failure in the effect; but for the integrity of a thing there is required the integrity of whatever contributes to the esse of the thing; for evil, as Dionysius says³⁰, arises from any single defect, whereas good arises from a cause entire. Hence we also see in syllogisms that, when the minor is contingent, the conclusion follows as contingent, even though the major is necessary.

It must be considered, second, that since a cause can be called necessary in two ways—namely, either because its disposition is always the same and cannot be changed, or because it necessarily produces its effect in such a way that it cannot fail to produce it—when Saint Thomas says that, although the first cause is necessary, nevertheless its effect can be contingent on account of the contingency of the second cause, he is not understood to mean that the first cause is necessary in the second way, but only in the first way. For, if taken in the second way, it involves a contradiction for some cause to be necessary and yet for its effect to be able not to be produced: for, if the effect can fail to be produced, the cause can fail to produce. On account of this Scotus rightly says, in II Sent., d. 1, q. 3³¹, that the philosophers latently conceded two contradictories when they said that something comes about contingently and that the first cause causes necessarily. This is also evident from this example of Saint Thomas. For he gives the example of the motion of the heavens, which he says is necessary; yet it is clear that this motion is indeed necessary in itself, but does not necessarily cause these lower things, as is said below in book III, c. 86, and in Prima, q. 115, a. 6.

Sense, therefore, is what stands together: that the first cause of some effect is necessary in itself, immutable according to the disposition by which it is active, and always disposed in the same way, and yet its effect comes about contingently, on account of the contingency and mutability of the second cause; not that the first cause is necessarily productive of its effect, and yet that effect comes about contingently.

XIV. To the first argument of Scotus, therefore ³² it is said first that it does not proceed against the sense of Saint Thomas. For it proceeds as if Saint Thomas held that these can stand together: that the first cause necessarily and absolutely produces its effect, and yet the effect comes about contingently, granted also that the first cause acts necessarily—not indeed with respect to the ultimate effect produced through the mediation of the second cause, but with respect to the second cause itself, namely in such a way that it acts necessarily upon the second cause. It is said second, from the doctrine of Saint Thomas in I Sentences, d. 38, a. 5, and De Veritate, q. 5, a. 9, ad 10, that since the power of the first cause is received in the second cause according to the mode of the second cause, when the first cause acts upon the second, if the second cause be contingent and defectible, the effect too will come about contingently and defectibly. Hence the assumption offered in proof of the consequence is false: for it stands together both that a moving cause, insofar as it is moved, is moved necessarily by the first cause, and yet does not move necessarily, because the action of the first cause is modified in the second cause according to the mode of the second cause itself.

2. To the second it is said that the first cause, producing an effect through the mediation of a second cause, does not attain the effect in any prior duration in which the effect is not attained by the second cause: although it is said to act prior, insofar as the second cause does not act except by the power of the first. Hence it is not necessary that the effect have its necessity from the first cause at some prior instant: but, being produced simultaneously by a necessary and a contingent cause, on account of the contingency of the second cause it too has contingency.

3. To the third, it is said first that having contingency from the first cause can be understood in two ways. In one way, that the first cause is the cause of the contingency of things. And in this way it is true that contingency is had from the first cause: for God causes both things and their necessity and their contingency. — In another way, that things are contingent on account of the contingency and inefficacy of the first cause, whose effect could be impeded. And in this way things do not have contingency from the first cause. It is said second that, if anything of those things which are naturally produced by the first cause through a contingent second cause were produced by the first cause alone, it would be contingent insofar as it is a thing: for, as far as it is in itself, it could fail and not be. It would also be contingent absolutely in the character of an effect: for it would be an effect naturally produced by a cause proper that can be impeded. It would not, however, be contingent in relation to the cause then producing it, but would be an effect freely produced.

4. To the fourth it is said that among the things produced immediately by God, that is, producible by God alone, some are things necessary in themselves, such as the celestial bodies and rational souls; but others are things contingent in themselves, such as grace, in accordance with what was said above ³³ in the second argument, namely because they are of such a nature that it belongs to them in themselves that they can be non-existent; yet nothing is contingent by a contingency belonging to the thing with respect to its cause, as if, namely, it had a contingent and impedi­ble cause; rather they are effects freely produced.

XV. Sixth, ³⁴ God knows each effect not only in itself but also in relation to any of its proximate causes. Therefore He knows that some things both occur and occur contingently. Therefore, with the certainty of the divine science, the contingency of things stands firm. — The antecedent is proved: because God is the knower of all esse, of which He is the principle. — The first inference is also evident: because the order of contingent things to their proximate causes is such that they proceed from them contingently. — But the second is proved as follows: because God's knowledge would not be true and perfect if things did not occur in this way, just as God knows them to occur. If, then, He knows that they themselves have esse at some time, or occur at some time, and contingently, then with the truth of His cognition and its certainty it stands that the effect occurs contingently.

XVI. As to the second ³⁵, he answers the objection made ³⁶. And he says that it fails in three ways ³⁷. The objection was: Every knowledge that concerns the contingent, when it is future, can be mistaken, since the opposite of what is judged may come about; otherwise it would be necessary. This is also evident from our knowledge, which concerning these things is merely conjectural. But God's knowledge cannot be mistaken. Therefore it cannot concern future contingents. But if it were said that, although divine science cannot be mistaken, it can nevertheless be changed according to the change of things through a new knowledge of a thing, this does not stand against the argument: for it is impossible that God should begin to know something anew, since He is immutable.

XVII. He answers, therefore, first ³⁸, that a falsehood is assumed, and that in that assumption the fallacy of the consequent is committed. A falsehood is indeed assumed, because it is not true that every cognition of a future contingent can be mistaken, or be changed in any way whatever. For the variation of what is later does not induce variability in what is prior, since it can happen that the ultimate effects are contingent while the first causes exist necessarily. And therefore, since the things known by God are posterior to His knowledge, and not prior to it as they are with us, their variation does not induce variation in the divine knowledge: neither, that is, from truth into falsity, nor from ignorance into cognition. — The fallacy of the consequent is also committed if, from the fact that our cognition of variable things is variable, it is argued that this happens in every cognition. Note that, when the argument is made thus, Our knowledge of variable things is variable; therefore every cognition of such things is variable, the fallacy of the consequent is not committed formally, since, as is said in the treatise on Fallacies of Saint Thomas ³⁹, that fallacy occurs only in conditional argumentations. Nevertheless, such a fallacy is committed virtually and fundamentally, as in this one, A man runs; therefore every animal runs: because there is virtually contained an argumentation from the positing of the consequent to the positing of the antecedent, by arguing thus, If a man runs, an animal runs; therefore, if an animal runs, a man runs: as if, namely, the consequent were altogether identical with the antecedent. Similarly in the case at hand there is virtually contained a like argumentation: as if it were altogether the same that our cognition of variable things be variable, and that absolutely the cognition of such things be variable.

XVIII. But a doubt arises concerning the first part of the reply. For although the variation of the posterior does not necessarily induce a variation of the prior in all cases, yet where the prior and the posterior must be adequate, there, necessarily, if one is varied, the other must be varied as well, if equality is to remain: for, if some quantity is removed from one of two equals, they no longer remain equal unless the same amount is removed from the other. Now, between divine knowledge and the thing known there must be adequation, since adequation belongs to the nature of true cognition. Therefore, once a variation has occurred in the thing, it is necessary either that the cognition be changed by a new estimation, or that it itself, while remaining the same, be false and inadequate.

2. For the clarification of this, it must be considered that the time in which a thing exists under some disposition is related in one way to our knowledge, and in another way to divine knowledge. For it is compared to our knowledge as to a thing existing within time. Hence it comes about that, when some disposition of a thing is known as present, both the thing known and the knowledge are understood to be measured by present time; but when the knowledge is directed toward something as future or as past, that thing is understood to be future or past in comparison with the knowledge itself as well. For when I judge that Socrates is sitting, Socrates' sitting is understood to be in the present time, in which my knowledge is; and when I judge that Socrates sat, Socrates' sitting is understood to be past with respect to the time in which my knowledge is; and similarly, when I judge that Socrates will sit, Socrates' sitting is understood to be future with respect to my knowledge. From these considerations it follows that, since a thing is differently disposed in different parts of time, it also, insofar as it is compared to our knowledge, undergoes variation. For if Socrates sits today, and I judge him to be sitting, his sitting is present to my knowledge; but if tomorrow he does not sit, and I still judge him to be sitting, the sitting will no longer be present to my knowledge, but past; and consequently an inequality remains between my knowledge and the thing, since I judge it to be in the time in which my knowledge is, and yet it is not in that time. But if equality is required, the judgment too must change: namely, that on the following day I judge Socrates not to be sitting but to have sat, just as he himself has changed from sitting to not sitting.

Time, however, is related to the divine knowledge not as to a thing contained under time, but as to that which is above all time, measured as it is by eternity, which is present to every difference of time. Therefore, however much a thing may vary in itself, it does not vary with respect to its reference to the divine knowledge: since it is always present to the divine gaze, in respect of every disposition of itself, for all the parts of time in which it is variously disposed. For if Socrates sits today, God always sees Socrates sitting today; and if tomorrow he does not sit, He always sees him not sitting tomorrow. And thus a thing never varies in relation to the divine knowledge so as to be at one time present to it, at another past, at another future; rather it is always present to it—although God knows that the thing is sometimes past and sometimes future for us. And thus, from the variation of the thing in itself, neither is the adequation of the divine knowledge and the thing known destroyed, the same knowledge remaining; nor must God form a new knowledge: because the thing does not vary in its order to the divine knowledge so as to stand to it now in one way, now in another—as happens with our knowledge, to which Socrates' sitting is sometimes present, sometimes past, sometimes future.

But what is brought forward about equal quantities does not compel. For when one quantity equal to another quantity is varied with respect to quantity, it is varied in its relation to the quantity to which it was equal just as it is varied in itself; and therefore the equality between them is destroyed. But what is understood by God, although it be varied in itself, is nevertheless not varied in relation to the divine cognition. Therefore the adequation between God's knowledge and the thing known by him is not destroyed.

XIX. But another doubt arises. If a thing always stands in the same way in relation to the divine cognition—since, before Christ was born, God knew that Christ would be born; and when he was being born, God knew that Christ was being born—it follows that now also God knows that Christ is going to be born and that Christ is being born. Yet this is false: since Christ is not now going to be born, nor is being born now.

2. It is answered that, when it is said, God now knows Christ to be about to be born, the present time imported by the word and the adverb can be taken either on the side of the cognition or on the side of the thing known. If it is taken on the side of the cognition, then God now knows Christ to be about to be born. For the sense is that the cognition of God by which He knows Christ to be about to be born is now present: namely, for the time in which it was true, as far as we are concerned, that Christ was about to be born. This is indeed most true: since the cognition of God is eternal, and the time in which it was true to say Christ is about to be born is present to the divine cognition from eternity.

But if it is held on the side of the thing known, then God does not now know that Christ is going to be born. For the sense would be that the very knowing is that Christ is now going to be born. That would be false knowing, since Christ is not now going to be born. Yet it does not follow that there is a change in the divine science, but only that God knows the change of things, while he knows that Christ is at one time, with respect to us, going to be born, and at another time has been born; and that one enuntiabile is now true, and the other at another time.

If, therefore, time is taken from the side of cognition, the falsity of the consequent is denied. And in proof of this, the consequence is denied. For although Christ is not now to be born, there is nevertheless now a cognition by which it is known that he was to be born at the time when it was true to say, Christ is to be born.

But if time is taken from the side of the thing known, the consequence is denied. For although the thing, in relation to divine cognition, always stands in the same way—since it is always present to itself according to every disposition of its being—yet in itself it changes, so that Christ's nativity is sometimes present to us, sometimes past, sometimes future. And therefore it is known by God to be sometimes present to us, sometimes past, sometimes future.

3. From these things it is clear what is the meaning of that proposition which Saint Thomas, in the First Part ⁴⁰, concedes, namely, Not everything God knew does He know, if it is referred not to things but to enunciables. For if the time imported by this verb knows is taken on the side of the knower, then whatever God knew He now knows. For the sense is that of whatever enunciable God had knowledge in a time past for us, He has knowledge of it even now, namely for that time in which it is true: because both the enunciable itself and the time in which it is true are always present to the divine gaze. — But if it is taken on the side of the enunciable known, then not everything God knew does He know: for He did not know every enunciable to be true in a time past for us such that He knows it to be true in a time present for us. For He knew this enunciable, Christ will be born, to be true before Christ was born: but He does not know that it is now true, because it is not true. To this sense, then, Saint Thomas admits that this proposition is true, Not everything God knew does He know: but not to the first sense.

4. But a doubt remains: why does he admit that proposition if it is referred to enuntiabilia, but not if it is referred to things? For just as an enuntiabile, remaining the same, varies from truth into falsity, so the same thing varies from being into non-being, and from one disposition into another. If, therefore, on account of the variation of the enuntiabile it is granted that not every enuntiabile that God knew he knows, then on account of the variation of the thing it should be granted that not every thing that God knew he knows.

It is answered that the case is not the same for that proposition if it is understood of enuntiabilia, and if it is understood of things. For when it is understood of enuntiabilia that God knew or knows something, the truth of the enuntiabile is signified to be together in time with what is imported by that verb along with the divine cognition: for when it is said, God knew Christ to be about to be born, it is signified that this enuntiabile had its truth at a past time, at which God had knowledge concerning it. Similarly, when it is said, God knows Christ to be about to be born, it is signified that at the present time both the truth of that enuntiabile and the divine cognition concerning it are together. And because not every enuntiabile that was true in past time is true in present time—although in present time God has cognition of it for the time for which it is true, in the manner explained above—therefore not every enuntiabile that God knew does he now know; understand "now" in the manner explained above, namely if the time on the side of the knowable is so disposed. — But when it is said that God knew or knows some thing, it is not imported that the thing is together with the divine cognition in time through what is imported by the verb, but only that the thing terminates the divine cognition. And because from eternity a thing terminates the divine cognition with respect to all its disposition, since all time is present from eternity to the divine cognition, therefore whatever thing God knew, he also now knows, because his gaze is always borne upon the thing, in whatever disposition it may be.

The first response of Saint Thomas, therefore, is that the major premise assumed in the objection is false ⁴¹.

XX. The answer is given, secondly, to the proof of the major premise ⁴²; and the assumption is denied; and it is shown that there the fallacy of the accident occurs. This assumption is indeed false: that the opposite of what is judged concerning a future contingent could come about—namely, as it is known by God. For although, when it is said, God knew or knows this to be future, a certain middle term is taken between the divine cognition and the thing known, namely the time of utterance, with respect to which the thing known is said to be future; nevertheless the thing is not said to be future with respect to the divine cognition, which, existing in the moment of eternity, is present to all things. And because what is cannot, with respect to that instant in which it is, not be; therefore the future thing known by God, as it is known by him, cannot come about otherwise, by supposition. Hence, if the time of utterance were removed, this would not be said to be known by God as future and as non-being, so that the question whether it can not be would have a place; but it would be said to be known as seen in its very existence, in which case the question whether it could then not be has no place.

The fallacy of accident is committed. For, since present and past time coexist with eternity, the relation of present or past time to the future is attributed to eternity, when it is said that what is known by God is future and not a being, as though it were future to the divine knowledge. In this per accidens there is deception: for, since the relation of present or past time to the future does not belong to time insofar as it coexists with eternity, but from elsewhere, namely insofar as it is distinguished from eternity, this ought not be attributed to eternity. Therefore, if it is attributed, there is deception secundum accidens.

Note that by this response he does not wish to exclude from God knowledge of the future as it is future to us, but only knowledge of the future as future in relation to His own knowledge; and knowledge of the future as it exists only in its causes, in the way in which we know the future. For thus, as we showed above ⁴³, a contingent future is not subject to certain knowledge. For God knows the future according to the esse it has in its causes, insofar as it is said to be future to us; and according to the esse it has in itself. On this account His knowledge of it, as future to us, is most certain: and the thing which is known in this way—namely, both as it is in its causes and as it is in itself—from this supposition, namely that it is known in itself, cannot come about otherwise at that time for which it is known according to its esse, although speaking absolutely it could come about otherwise.

XXI. Third, an answer is given to the proof of what was assumed ⁴⁴. For it is granted that what is future and known by God is necessary, since each thing is known as if seen present: but it is necessary not absolutely, or, as some say, by the necessity of the consequent; rather under a condition, or by the necessity of the consequence. Hence arguments of this kind err according to the fallacy of composition and division. For when it is said, What is seen to be sitting must sit, taken de dicto and in the composite sense it is true, for this proposition is necessary: What is seen to be sitting is sitting; but de re, that is, in the divided sense, it is false, for it is not necessary that Socrates, who is seen to be sitting, sit, since he sits contingently. Therefore, because it is not necessary in the divided sense that Socrates, who is seen to be sitting, sit, to conclude that what is seen to be sitting is not necessarily sitting in the composite sense—that is, insofar as it stands under cognition—is to argue from the divided sense to the composite.

It must be noted that Saint Thomas calls the proposition of the composite sense a proposition "of what is said" (de dicto), while the one of the divided sense he calls a proposition "of the thing" (de re). For in that of the composite sense, the mode is posited as the determination of the whole thing said: when it is said, That which is seen to sit necessarily sits, the sense is that this proposition is necessary, That which is seen to sit sits; where it is clear that the mode of necessity determines everything that is said. In that of the divided sense, however, the mode determines the thing of the subject: when it is said, That which is seen to sit is necessary to sit in the divided sense, the sense is that this thing, say Socrates, who is seen to sit, has it that it sits of necessity and not contingently.

As for the third point ⁴⁵, the conclusion is confirmed by the authority of Wisdom 8, Ecclesiasticus 39, and Isaiah 48.