Commentaria in Summam contra Gentiles, Liber I

According to the corollary ¹ it is: The divine will does not remove contingency, nor does it impose absolute necessity upon things.

I. It is proved first. God wills some things to be contingent. Therefore his will does not remove contingency from things. — The antecedent is proved. Because God wills all things pertaining to a thing. But it befits some things, according to the mode of their nature, that they be contingent and not necessary. — The consequence is also proved. Because the efficacy of the divine will requires that a thing be in the manner in which God wills it to be: just as also in natural things, when the power of the agent is strong, it assimilates its effect to itself both as regards species and as regards accidents.

It must be noted, according to the doctrine of Saint Thomas on Book VI Metaph., lecture 3, that God stands differently toward contingent and necessary things than other causes do. For God, because He is the cause of being insofar as it is being, is therefore also the cause of all the accidents of being insofar as it is being. Among these are the necessary and the contingent. Hence, whatever He willed to be necessary, to these He gave necessary causes; but whatever He willed to be contingent, to those He gave contingent causes. Other causes, however, are indeed causes of their effects' existing: not, however, of its being necessary or contingent; rather they produce these effects according to the law of necessity or contingency instituted by a higher cause. Hence it follows in certain other causes that, once the cause is posited, its effect is posited necessarily and absolutely. But in the divine cause, or in His will, it follows that, once the divine will is posited, the effect exists necessarily from necessity or contingently, according to His disposition. On this account Saint Thomas said here that from the efficacy of the divine will there proceeds the fact that an effect exists necessarily or contingently, as He wills: namely, because being insofar as being is subject to Him, and consequently every disposition of being.

II. Second. The completion of the universe requires that there be certain contingent things. Therefore, etc. The antecedent is evident, because otherwise not all the degrees of being would be contained in the universe. The consequence, however, is proved as follows: God wills principally the good of the universe of His effects rather than any particular good, since in it a more complete likeness of His goodness is found.

But this argument seems not to conclude. For according to the doctrine of St. Thomas, God can produce more species than have been produced, and more perfect ones ². But each species signifies one degree of being. Therefore many degrees of being are lacking to the universe. Therefore it is not unfitting that some degree of being be not contained in the universe. The opposite of which is held here.

It is answered that there is a twofold grade of being: one, namely, transcendent and common; the other particular. Necessary and contingent are common and transcendent grades, as following upon being inasmuch as it is being, as Saint Thomas says in Book VI of the Metaphysics³: because every being is either necessary or contingent. But each nature and species is said to be a particular grade. Therefore, for the perfection of the universe it is required that all common and transcendent grades be contained in it, and of these Saint Thomas speaks; but not that all possible particular grades of being be contained in it.

III. Thirdly⁴. And it is a confirmation of the preceding argument. The order of the universe requires that there be some variable causes. Therefore there are also some contingent effects. Therefore, etc. — The antecedent is proved: because bodies belong to the perfection of the universe, and they do not move unless moved. — The first consequence is also proved: because contingent effects follow from a variable cause, since an effect cannot be of firmer being than its cause. — The last is also evident: because God wills the good of the universe, which consists in a certain order.

IV. Concerning that proposition, Contingent effects follow from a variable cause, and its proof, there is a threefold doubt. First, because the variation of a contingent effect is considered with respect to esse. But the variation of bodies assigned here is variation with respect to position. Now it does not follow that an effect variable with respect to esse must proceed from a cause variable with respect to position: for it does not follow that, if an effect is invariable with respect to esse, it is of firmer esse than its cause, since it can vary with respect to position, just as its cause does; and a cause variable with respect to position can be invariable with respect to esse, as the heavenly bodies are. Therefore it is not necessary that the effect of a variable cause be contingent in that way.

Second⁵, because the defect of the sun is caused by the motion of the heavenly bodies. Yet this is not contingent, but necessary.

Third⁶, because Aristotle, in VIII Physics⁷ and I On Generation, posits one regular motion in order to preserve the perpetuity of generation. But what is perpetual is not contingent but necessary, especially according to Aristotle⁸. Therefore, etc.

V. For the clarification of the first doubt, it must be considered that, as Saint Thomas teaches in Book VI of the Metaphysics, at the passage cited above⁹, a cause that acts through motion requires a determinate and disposed matter; and because it sometimes happens that the matter is indisposed, the power of such an agent does not attain its effect; and therefore from a variable cause there follows a contingent effect, namely that effect which proceeds from it insofar as it stands subject to variation. In such a process, moreover, the condition of cause and effect is equal: for just as the cause can be impeded by the indisposition of the matter from producing, so the effect can be impeded from being produced. And because the esse of the cause, as causing, is to produce—for from this it has formally that it is actually causing—and to be produced is the esse of the effect as actually produced, for it is produced formally by production: therefore the effect in this order is not of weaker esse than its cause.

To the doubt, therefore, it is said that the variation of the cause assigned here is understood not only according to place or position, but also according to the esse of the cause itself as it actually causes, in the manner explained above. For from a cause variable in this way—that is, one which can produce and can be impeded from producing—there proceeds an effect variable according to esse, namely, one which can be produced and not produced. And consequently it is contingent.

This proposition can be expounded in a second way: that from a cause variable according to accidental esse, which is a variation according to position alone, there must proceed a variation according to the substantial esse of the effect, when the variation of the cause is a necessary condition of the agent, or is the reason for acting upon the substantial esse of the effect. For an effect, insofar as it proceeds from a cause, ought not to be of firmer esse than the cause is with respect to its reason for acting. And therefore, if the effect is produced according to its substantial esse by a cause acting insofar as it undergoes variation, it must receive an esse that is variable from such a cause.

Therefore the minor premise is assumed falsely. And when it is argued that it does not follow that, if an effect is invariable in its esse, it is of firmer esse than its cause, this is denied. On the contrary, it does follow, because an effect proceeds from such a cause not only with respect to local motion but also with respect to substantial esse, which, if it were invariable, the effect, as effect, would be of firmer esse than its cause as cause.

VI. To the second doubt¹⁰ it is answered that the motion of the heavens is not absolutely the cause of the defect of the sun, but rather the interposition of the moon between the sun and our sight, which indeed arises from the planets existing in a certain position. And because by the motion of the heavens the planets arrive at that position, therefore it can be said that the motion of the heavens is in some way the cause of such a defect: supposing, I say, that the planets are in positions not suited to that effect. But absolutely it is not the cause: because, even if the celestial bodies stood still, such a defect of the sun could occur, with the planets existing in a suitable disposition. And thus a variable cause, as variable, is not the cause of that effect.

A second reply might be that the defect of the sun is an effect contingent in its own nature: since it can fail to be; indeed, as a matter of fact it sometimes exists and sometimes does not; although it is necessary with respect to its cause, namely because, once its cause is posited, it cannot fail to be.

But since St. Thomas does not seem to speak here of the contingency of the effect in itself as a thing, but rather as it is an effect and in relation to its cause, therefore it may be said, third, in conformity with the answer to the first doubt, that the cause of the eclipse is an unchanging cause in the character of a cause, because it can never be impeded from producing it. Hence the effect, in the character of an effect, is likewise unchanging: for once the cause is posited, it cannot fail to be produced. — And if it be said that every agent through motion is changeable in this way in the character of a cause, it is replied that this is true of an agent by way of transmutation of matter; not, however, of an agent by the necessary conveyance of bodies to a determinate place, which is how heaven was said to be able to be called, by its motion, the cause of the eclipse.

VII. To the third¹¹ it is said that in the motion of the first mobile there are two things: namely, the variation of position itself according to its parts; and the uniformity and perpetuity of the motion. The perpetuity of generation, therefore, derives from the motion of the heavens not by reason of variation absolutely, but by reason of the uniformity and perpetuity of such variation. For just as the alternation of generation and corruption is traced, as to its cause, to the alternation of the positions of the parts of the first mobile, so its perpetuity is traced as to its cause to the perpetuity of that alternation. Hence the argument to the contrary does not conclude. For an effect that proceeds from a variable cause, insofar as it is variable, is contingent; but not that which proceeds from it insofar as it has uniformity and perpetuity in such variation. For it can be necessary with a necessity like that of its cause, namely in the perpetuity of variation: as is evident in the motion by which the lower heavenly bodies are moved by the first mobile. And in this way Aristotle held that the necessity of perpetual generation and corruption comes from the uniform motion of the first mobile.

VIII. Fourthly¹²: God wills something in a creature not by absolute necessity, but by supposition. Therefore from the divine will absolute necessity cannot be concluded in things. Therefore contingency is not removed by it. — The first consequence is proved, because necessity ex suppositione in the cause cannot conclude absolute necessity in the effect. — The second is also evident, because only absolute necessity excludes contingency from things.

It does not follow, therefore, that if God wills something, that thing happens of necessity; but rather that this conditional is true and necessary, If God wills something, it will be. Yet the consequent will not be necessary.

2. For the clarification of this argument, it must be considered that contingency and absolute necessity are opposed to one another by their formal rationes, and therefore cannot belong to the same thing. For contingent is that which in itself and absolutely can be non-being; necessary, that which cannot be non-being. Hence wherever absolute necessity is posited, contingency must be entirely removed. — But necessity ex suppositione is not repugnant to contingency. That is called necessary ex suppositione which cannot be non-being once some supposition is made. Now, being able absolutely and in itself not to be, and not being able not to be once some supposition is made, are not opposed: for Socrates absolutely can fail to be moving; but given that he runs, he cannot fail to be moving. Hence from the fact that something is posited as necessary ex suppositione, contingency need not be removed from it. And so, since from God's willing something it follows that that thing be only ex suppositione necessary—because it cannot stand together that God wills a thing to come about and that it not come about—but not absolutely necessary, contingency need not be taken away from things by the will of God.

3. Concerning that proposition, It does not follow that if God wills something, it happens of necessity, note that the phrase of necessity can be taken on the side of the conditional and the consequence, and it can be taken on the side of the consequent. In the first way, the sense would be that this conditional is not necessary, If God wills something to happen, it will happen. And then the proposition is false. Indeed Saint Thomas says that the conditional itself is necessary: for the opposite of the consequent cannot stand with the antecedent, on account of the efficacy of the divine will.

In the second way, the sense is that the consequent of it, This will happen, is not in itself absolutely necessary. And this sense is true, and this is what Saint Thomas intends. For it does not follow from the fact that God wills the Antichrist to be that this is absolutely necessary, namely that the Antichrist will be.

It must also be noted that this is to be understood of the act of the will insofar as it is posited as terminated to the thing willed absolutely; but not if the mode of necessity is posited as willed. For although it does not follow, God wills an eclipse of the sun to occur, Therefore it will occur necessarily, because this consequence is founded upon this false proposition, Whatever God wills to occur will occur necessarily, yet it does follow well that God wills an eclipse to occur necessarily, Therefore it will occur necessarily.

IX. But a most difficult doubt arises. For, admitting that from the will of God there does not follow an absolute necessity in things—indeed, although the thing willed by God remains in itself contingent, it is nevertheless necessary ex suppositione—it seems that at least the consequent is inevitable and immutable; and consequently that the divine will imposes upon things willed such a necessity as takes away both free choice and all deliberation. For when something depends necessarily on some antecedent, if the antecedent is inevitable, the consequent too will be immutable and inevitable, and therefore it is futile to strive that it not come about: just as, if Socrates could not be changed from running, neither could he be changed from motion; and it would be futile to wish to strive that Socrates not be moved, if he cannot cease from running. Since, then, the divine will is immutable, it follows that what is willed by God is immutable and inevitable. And consequently it is futile to be solicitous to pursue what God wills not to be, or to strive for the opposite of what He wills to be in the future. And thus all human solicitude is taken away.

X. For the clarification of this doubt, it must be considered, from the teaching of Saint Thomas in the First Part, q. 19, a. 8, and q. 22, a. 4, ad 1, and Metaphysics VI ¹³, that since God is the supreme cause, to which all other causes, both necessary and contingent, are subject, He disposes both that something come to pass and how it ought to come to pass and from what causes. For those things which He wills to happen necessarily and infallibly, He wills to happen through necessary and infallible causes; but those things which He wills to happen fallibly and contingently, He wills to happen through other contingent and fallible causes intervening, as an abundance of crops through the plowing of the earth and the sowing of seed. Hence, because an effect depends on all its causes, if a second cause is not posited, the effect will not follow. Therefore, if an effect willed by God is to follow through certain causes intervening, those causes must be posited: for it has been ordained that it should come to pass only through them. Foolish indeed would be the man who wished for harvests yet refused to plow his field or commit seed to the earth; or who wished for fruit yet refused to have trees planted; or who wished to grow rich from trade without any care or effort.

It is said, therefore, first, that the divine will does not abolish our diligence: for God wills certain things to come to us in such a way that they are to be acquired by our effort and our diligence, and that they occur contingently. If this is not done, the effect will not follow.

It is said second, that it would be foolish to attempt that something be simultaneously willed by God and yet its opposite come about, as that God will the death of someone and that death not occur: since no one can impede the efficacy of the divine will. Yet it is not foolish to attempt the opposite of what God wills, for instance to seek life for him whose death God wills: because God wills this man's death to come about from a contingent and impedeable cause; but it is not foolish to attempt an impediment to a cause which can absolutely be impeded, and consequently to the opposite effect.

2. But if it is pressed further that, although the cause of death is a cause that is in itself impedeable, yet if God wills that effect to come about through that cause, the cause will not in fact be impeded, on account of the efficacy of the divine will — it is said that indeed it will not be impeded; yet, because God wills that the effect proceed from it fallibly and impedeably, it could in itself be impeded. And therefore one who strives for this does not strive for what is impossible, but for what is possible, even though he does not attain his aim. For the proposition, It is foolish to strive for the opposite of what God wills to be future is indeed true in the composite sense: its sense is that it is foolish to strive at once for this whole thing together, namely that something be willed by God and that it not come about. But it is false in the divided sense. Its sense there is that, taking something willed by God, say the death of Socrates, it is foolish to strive for its opposite. This, however, is false: because God wills that death itself come about defectibly; and consequently, if someone strives that it not come about, he does not act foolishly, as laboring at what is impossible; rather, he strives for what can in itself fail to come about.

3. Hence, if by infallible and inevitable is understood that which, considered in itself, cannot fail to occur: it is denied that if the antecedent of a necessary conditional be immutable, the consequent is inevitable; and likewise it is denied that the divine will imposes inevitability upon all things. — But if what cannot fail to occur is understood ex suppositione of something, all the foregoing are granted, yet it is denied that such inevitability destroys contingency and freedom along with deliberation. For necessity ex suppositione, and contingency and freedom, stand together at once, as was shown above ¹⁴. Therefore St. Thomas says in Veritate, q. 23, a. 5, ad 3, that although these are incompossible, “God wills this man to be saved” and “this man is damned”; nevertheless these are compossible: “God wills this man to be saved” and “this man can be damned.” For with the divine will there stands the power of the effect's failing, although the effect of the divine will cannot stand together with its not being.