Commentaria in Summam contra Gentiles, Liber III

The second doubt¹ is this: because it seems that, if divine providence extends to all things, all things happen of necessity.

I. To exclude this, St. Thomas lays down this conclusion: Divine providence excludes neither contingency nor necessity from things.

It is proved first. The operation of divine providence does not exclude secondary causes. But from secondary causes some effects are called contingent or necessary, not from remote causes: as appears in the fructification of a plant, which is contingent, although the sun is a cause acting of necessity. Therefore not all effects that are subject to providence will be necessary.

Note that, when the sun is said to be a cause acting of necessity, a cause can be said to act necessarily in two ways. In one way, because it can in no way be impeded from its effect. And it is not taken in this sense here: because the effects to which the power of the celestial bodies extends are impeded many times. — In another way, because, as far as is in itself, it necessarily tends to the production of its effect, unless it is impeded. And in this sense the sun is understood to act of necessity. For the sun cannot be altered from its natural disposition. And therefore by its motion and its light, unless it is impeded by something resisting, it necessarily produces its effect, as far as is in itself, as is said in Verit., q. vi, a. 3, ad 3. But of this enough has been said in the preceding; ² and it will be said more fully below in chapter 86.

Second. Then not all the grades of beings would be preserved. But this is against divine providence, to which it belongs that the grades of beings (namely, the common ones, according to what was said earlier ³) that are possible be fulfilled. Therefore, etc. — The consequence is proved. Because being is divided per se into the necessary and the contingent.

II. Third. That all things happen of necessity is repugnant to divine providence. Therefore, etc. — The antecedent is proved. Because it belongs to divine providence to establish and preserve order in things. But that all things happen of necessity takes away the order of things according to their nearness to and distance from God, in which the beauty of order appears: while certain things, namely the separated substances, as closest to God, are altogether immobile; certain others, namely the celestial bodies, receive a certain kind of immobility, in this, that they are always moved in the same way; certain others, however, namely those that follow upon these, stand farther from immobility, so that they are not always moved in the same way, and consequently do not happen of necessity.

2. Concerning what is intended in this argument, namely that some things are distanced from God more and some less, a doubt occurs. For all creatures are at an infinite distance from God: since He Himself is of infinite perfection, while the creature is of finite. Therefore one thing does not stand more distant from God than another: for from an infinitely distant terminus one thing does not stand more distant than another.

It is answered by denying the consequence. For although, from that from which some things are infinitely distant according to positional distance, one thing perhaps could not stand more distant than another; nevertheless, from that from which some things are distant in infinitum according to perfection, one thing can stand more distant than another. For the less a thing has of perfection, the more it stands distant from the most perfect; and the more a thing has of perfection, the more it approaches the most perfect itself, although its perfection is infinitely distant from that infinite perfection. For such approach and distancing imports nothing other than the participation of greater or lesser perfection from that infinite perfection, or a greater or lesser likeness with it, as is had in Quolib. XI, a. 1, ad 5. Nor is it unfitting that there be some participations of that infinite perfection of which one is in itself more perfect than another, although all stand at an infinite distance from the first.

III. Fourth. If divine providence requires that all things be necessary, nothing in things would be corruptible, nor consequently generable. And thus the whole part of generable and corruptible things would be taken away from things. But this detracts from the perfection of the universe. Therefore, etc. — The antecedent is proved. Because the necessary always is: but nothing corruptible always is.

Fifth: and it is a confirmation of the preceding argument. Motion, and all movable things, would be taken away from things. Because generation and corruption would be taken away, the contingency of all things being removed. But in every motion there is generation and corruption: since in everything that is moved, something begins to be and something ceases to be.

Sixth. Divine providence does not impede motion from things. Therefore neither is the weakening of their power impeded, nor the impediment from the resistance of another. Therefore necessity is not imposed on all things that are provided for. — The first consequence is proved: because the weakening of the power of some substance, and its change, would be done away with. — The second, indeed, is proved. Because from the weakening of power and its impediment it happens that a natural thing sometimes fails from that which befits it according to nature, so that thus effects do not come forth of necessity.

Seventh. It is manifest that some causes are contingent, from the fact that they can be impeded from the production of their effects. Therefore it would be against the notion of providence that all things happen of necessity. — The consequence is proved. Because in those things that are duly governed by providence, nothing should be in vain: but such defective causes would be in vain.

Concerning the proved conclusion there occurs a doubt from Aureolus, reported by Capreolus, in I Sent., d. xl ⁴: but because it is solved from those things which St. Thomas will say below ⁵, where he will determine concerning the certainty of divine providence, there is no need to dwell on it in this place.