Summa contra Gentiles3.94 Chapter XCIV. Of the certainty of divine providence

A difficulty, however, arises from what has been said. For if all, even the contingent, happenings of this lower world, are subject to divine providence, it would follow seemingly that either providence is uncertain, or all happenings necessary.

For the Philosopher proves (6 Metaph.) that if we suppose every effect to have a per se cause, and again that given any per se cause, we must of necessity grant the effect: it will follow that all future events happen of necessity. For if every effect has a per se cause, every effect will be reducible to some cause either present or past. Thus if it be asked whether a certain man will be killed by robbers, this effect is preceded by a cause which is his being met by the robbers; and this effect is again preceded by another cause, namely that he went out; and this again was preceded by another cause, namely that he went to fetch some water; and this by another cause, namely that he was thirsty; and this was caused by his partaking of salt meat; which he is either eating now or has ate already. Accordingly if given the cause we must necessarily grant the effect: if he eats the salt meat, he is of necessity thirsty; if he thirsts, it is necessary that he wish to seek water; and if he wish to seek water, that he leave his house; and if he go out, that the robbers meet him; and if they meet him, that they kill him. Therefore from first to last, it is necessary that this eater of salt meat be killed by robbers. The Philosopher concludes then that it is untrue that given the cause, the effect must of necessity be granted also, since some of these causes may be ineffective. Nor again is it true that every effect has a per se cause: because that which is accidental, namely that the man who wants water should meet some robbers, has no cause.

This argument proves then that all effects reducible to a per se cause, whether present or past, which being given, the effect follows of necessity, happen themselves of necessity. Either therefore we must say that not all effects are subject to divine providence: and thus providence would not be about all things, contrary to what was proved above: or we must say that granted providence, it is not necessary for its effects to follow: and then providence will not be certain: or that all things must needs happen of necessity: for providence is not only in the present and the past, but from eternity, since nothing can be in God that is not eternal.

Further. If divine providence be certain this conditional proposition must be true: If God foresaw this, it will be. Now the antecedent of this proposition is necessary, for it is eternal. Therefore the consequence is necessary: because whenever the antecedent of a conditional proposition is necessary, the consequence is likewise necessary; so that the consequence is like a conclusion of the antecedent, and whatever follows from a necessity is itself a necessity. Accordingly if divine providence is certain, all things must happen of necessity.

Moreover. Supposing a thing to be foreseen by God, for instance that so and so will reign. Either then it is possible for it to happen that he does not reign, or it is not possible. If it be not possible for him not to reign, then it is impossible: therefore it is necessary that he will reign. On the other hand, if it be possible that he will not reign, then, since given a possibility nothing impossible follows, and whereas it does follow that divine providence is at fault, it remains that it is not impossible for divine providence to fail. Consequently it follows, if all things are foreseen by God, that either divine providence is uncertain, or that all things happen of necessity.

Again. Tully argues thus (2 De Divin., vii.): If all things are foreseen by God, the order of causes is certain. If this be true all things are subject to fate. If all things are subject to fate, nothing is subject to our power, and there is no such thing as free-will. Therefore if divine providence is certain, there is no free-will. And it will also follow that there is no such thing as a contingent cause.

Besides. Divine providence does not exclude intermediary causes, as we have proved. But some causes are contingent and defectible. Therefore the effect of divine providence may fail. Therefore God’s providence is uncertain.

In order to solve these difficulties, we must recall some points already laid down: so as to make it clear that nothing escapes from divine providence; and that the order of divine providence is utterly unchangeable; and that, notwithstanding, it does not follow that whatever results from divine providence, must happen of necessity.

First, we must observe that as God is the cause of all existent things by giving them their very being, the order of His providence must needs include all things: because to those things to which He has given being, He must grant a continuance of being, and perfection by attaining their last end.

Now in everyone that exercises providence there are two points for consideration, namely forethought about the order of things, and establishment of the premeditated order in the things subject to providence, the former pertaining to the cognitive, and the latter to the executive faculty: and there is this difference between them, that in designing the order, providence is so much the more perfect, as its order is more able to reach the most minute things. For it is owing to our defective knowledge which cannot comprise all individual things, that we are unable to arrange beforehand all the particulars; and a man is considered more fit to make provision according as his foresight extends to more particulars: and one whose foresight extends only to general considerations, has but a small share of prudence. The same may be observed in all productive arts. On the other hand, as regards the causing of the premeditated order to be in things, the providence of the governor is the higher in order 1 Ch. Ixxvii. 2 Ch. lxiv. seqq. 3 Ch. lxxvii.

and perfection, according as it is more universal, and brings about the realization of its forethought through more ministers: in fact the mere organization of these ministers has a large place in the order of providence.—Now God’s providence must be supremely perfect, because He is simply and universally perfect, as we proved in the First Book. Consequently in his providence He orders all things, even the most trivial, by the eternal forethought of His wisdom: and whatsoever things operate, do so as instruments moved by Him, and serve Him obediently, so as to bring forth into the world the order of providence excogitated, as it were, from eternity.—And if all things that are capable of action, must needs act as His ministers, it is impossible that any agent hinder the execution of divine providence, by acting contrary thereto. Nor again is it possible for divine providence to be hindered through a defect in any agent or patient, since every power, active or passive, is caused in things according to God’s disposition. Again it is impossible for the execution of divine providence to be prevented through a change in the author of providence, since God is utterly unchangeable, as we have proved. It. follows therefore that divine providence cannot possibly fail.

Secondly it must be observed that every agent aims at a good, and at a greater good so far as it is able, as we have proved. Now, the good and the better are not the same as considered in the whole and as considered in the parts. For in the whole the good consists in integrity which results from the order and composition of parts. Consequently for the whole it is better that there be disparity of parts, which is necessary for the order and perfection of the whole, than that all the parts be equal, each one being on a level with the most excellent part; whereas each part of inferior degree would be better, considered in itself, if it were on the same level as a higher part. Take, as an example, the human body: the foot would be a more excellent part if it possessed the beauty and power of the eye: but the whole body would be more imperfect, if it were deprived of the service of the foot. Accordingly the intention of the particular agent differs from that of the universal agent: for the particular agent aims at the good of the part absolutely, and makes it as good as it can; whereas the universal agent aims at the good of the whole. Consequently a defect is beside the intention of the particular agent, but according to the intention of the universal agent. Thus the generation of a female is clearly beside the intention of a particular nature, namely, of this particular virtue in this particular seed, the tendency of which is to make the embryo as perfect as possible: on the other hand it is the purpose of universal nature, namely of the power of the universal cause of generation in inferior beings, that a female be generated, which is a necessary condition for the generation of many animals. In like manner corruption, diminution, and every defect is in the purpose of universal nature, but not of the particular nature: because each thing shuns deficiency and, for its own part, aims at perfection. It is clear, then, that the particular agent aims at the greatest possible perfection of its effect in its kind; while the universal nature aims at a particular perfection in a particular effect, for instance the perfection of a male in one effect, that of a female in another.—Among the parts of the whole universe the first distinction to be observed is between the contingent and the necessary: since the higher beings are necessary, incorruptible and unchangeable: and the lower a thing is, the more it falls short of this condition: so that the lowest are corruptible in their very being, are changeable in their disposition, and produce their effects, not of necessity but contingently. Wherefore every agent that is a part of the universe has a tendency to remain firm in its being and natural disposition, and to establish its effect: while God, who governs the universe, intends to establish some of His effects by way of necessity, and others by way of contingency. Accordingly He adapts various causes to those effects, to some necessary, to others contingent causes. Therefore it belongs to the order of divine providence, not only that such and such an effect be produced, but that it be caused necessarily, and that some other effect be produced contingently: and consequently some of the things subject to divine providence are necessary, and some contingent, and not all necessary.—It is therefore evident that although divine providence is the per se cause of a particular future effect; and although it is present and past, yet more truly eternal: it does not follow, as the first argument pretended, that this particular effect necessarily will be; for the divine providence is the per se cause that this particular effect will happen contingently. And this cannot fail.

Wherefore it is clear that this conditional proposition is true: If God foresaw that this would happen, it will be so, as the second argument stated. But it will be as God foresaw that it would be. Now, He foresaw that it would happen contingently. It follows then infallibly that it will be, contingently and not of necessity. It is also clear that if this thing which we suppose to be foreseen by God as future, be of a contingent nature, it will be possible for it not to happen considered in itself: for it is foreseen in such a way as to be contingent, and possible not to be. Yet the order of divine providence cannot fail but that it will happen contingently. Thus the third argument is solved. Consequently we may say that the man in question will not reign if we consider the statement in itself, but not if we consider it as foreseen.

Again the argument advanced by Tully appears of small account in the light of what we have said. For seeing that not only effects but also causes and modes of being are subject to divine providence, as is clear from the foregoing, it does not follow, if all things are ruled by divine providence, that nothing is under our control: for they are foreseen by God so as to be freely done by us.

Nor can the defectibility of second causes, by means of which the effects of providence are produced, deprive divine providence of certainty, as the fifth objection argued. For God Himself works in all things according to the decree of His will, as we proved above. Consequently it belongs to His providence sometimes to allow defectible causes to fail, and sometimes to preserve them from failing.

Such arguments as might be used to prove the necessity of things foreseen by God from the certitude of His knowledge, were solved above when we were treating of the divine knowledge.