Summa Theologica, by St. Thomas Aquinas, [1947], at sacred-texts.com
We next consider the effects of the Divine government in particular; concerning which four points of inquiry arise:
(1) Whether creatures need to be kept in existence by God?
(2) Whether they are immediately preserved by God?
(3) Whether God can reduce anything to nothingness?
(4) Whether anything is reduced to nothingness?
Objection 1: It would seem that creatures do not need to be kept in being by God. For what cannot not-be, does not need to be kept in being; just as that which cannot depart, does not need to be kept from departing. But some creatures by their very nature cannot not-be. Therefore not all creatures need to be kept in being by God. The middle proposition is proved thus. That which is included in the nature of a thing is necessarily in that thing, and its contrary cannot be in it; thus a multiple of two must necessarily be even, and cannot possibly be an odd number. Now form brings being with itself, because everything is actually in being, so far as it has form. But some creatures are subsistent forms, as we have said of the angels (Q[50], AA[2],5): and thus to be is in them of themselves. The same reasoning applies to those creatures whose matter is in potentiality to one form only, as above explained of heavenly bodies (Q[66], A[2]). Therefore such creatures as these have in their nature to be necessarily, and cannot not-be; for there can be no potentiality to not-being, either in the form which has being of itself, or in matter existing under a form which it cannot lose, since it is not in potentiality to any other form.
Objection 2: Further, God is more powerful than any created agent. But a created agent, even after ceasing to act, can cause its effect to be preserved in being; thus the house continues to stand after the builder has ceased to build; and water remains hot for some time after the fire has ceased to heat. Much more, therefore, can God cause His creature to be kept in being, after He has ceased to create it.
Objection 3: Further, nothing violent can occur, except there be some active cause thereof. But tendency to not-being is unnatural and violent to any creature, since all creatures naturally desire to be. Therefore no creature can tend to not-being, except through some active cause of corruption. Now there are creatures of such a nature that nothing can cause them to corrupt; such are spiritual substances and heavenly bodies. Therefore such creatures cannot tend to not-being, even if God were to withdraw His action.
Objection 4: Further, if God keeps creatures in being, this is done by some action. Now every action of an agent, if that action be efficacious, produces something in the effect. Therefore the preserving power of God must produce something in the creature. But this is not so; because this action does not give being to the creature, since being is not given to that which already is: nor does it add anything new to the creature; because either God would not keep the creature in being continually, or He would be continually adding something new to the creature; either of which is unreasonable. Therefore creatures are not kept in being by God.
On the contrary, It is written (Heb. 1:3): "Upholding all things by the word of His power."
I answer that, Both reason and faith bind us to say that creatures are kept in being by God. To make this clear, we must consider that a thing is preserved by another in two ways. First, indirectly, and accidentally; thus a person is said to preserve anything by removing the cause of its corruption, as a man may be said to preserve a child, whom he guards from falling into the fire. In this way God preserves some things, but not all, for there are some things of such a nature that nothing can corrupt them, so that it is not necessary to keep them from corruption. Secondly, a thing is said to preserve another 'per se' and directly, namely, when what is preserved depends on the preserver in such a way that it cannot exist without it. In this manner all creatures need to be preserved by God. For the being of every creature depends on God, so that not for a moment could it subsist, but would fall into nothingness were it not kept in being by the operation of the Divine power, as Gregory says (Moral. xvi).
This is made clear as follows: Every effect depends on its cause, so far as it is its cause. But we must observe that an agent may be the cause of the "becoming" of its effect, but not directly of its "being." This may be seen both in artificial and in natural beings: for the builder causes the house in its "becoming," but he is not the direct cause of its "being." For it is clear that the "being" of the house is a result of its form, which consists in the putting together and arrangement of the materials, and results from the natural qualities of certain things. Thus a cook dresses the food by applying the natural activity of fire; thus a builder constructs a house, by making use of cement, stones, and wood which are able to be put together in a certain order and to preserve it. Therefore the "being" of a house depends on the nature of these materials, just as its "becoming" depends on the action of the builder. The same principle applies to natural things. For if an agent is not the cause of a form as such, neither will it be directly the cause of "being" which results from that form; but it will be the cause of the effect, in its "becoming" only.
Now it is clear that of two things in the same species one cannot directly cause the other's form as such, since it would then be the cause of its own form, which is essentially the same as the form of the other; but it can be the cause of this form for as much as it is in matter---in other words, it may be the cause that "this matter" receives "this form." And this is to be the cause of "becoming," as when man begets man, and fire causes fire. Thus whenever a natural effect is such that it has an aptitude to receive from its active cause an impression specifically the same as in that active cause, then the "becoming" of the effect, but not its "being," depends on the agent.
Sometimes, however, the effect has not this aptitude to receive the impression of its cause, in the same way as it exists in the agent: as may be seen clearly in all agents which do not produce an effect of the same species as themselves: thus the heavenly bodies cause the generation of inferior bodies which differ from them in species. Such an agent can be the cause of a form as such, and not merely as existing in this matter, consequently it is not merely the cause of "becoming" but also the cause of "being."
Therefore as the becoming of a thing cannot continue when that action of the agent ceases which causes the "becoming" of the effect: so neither can the "being" of a thing continue after that action of the agent has ceased, which is the cause of the effect not only in "becoming" but also in "being." This is why hot water retains heat after the cessation of the fire's action; while, on the contrary, the air does not continue to be lit up, even for a moment, when the sun ceases to act upon it, because water is a matter susceptive of the fire's heat in the same way as it exists in the fire. Wherefore if it were to be reduced to the perfect form of fire, it would retain that form always; whereas if it has the form of fire imperfectly and inchoately, the heat will remain for a time only, by reason of the imperfect participation of the principle of heat. On the other hand, air is not of such a nature as to receive light in the same way as it exists in the sun, which is the principle of light. Therefore, since it has not root in the air, the light ceases with the action of the sun.
Now every creature may be compared to God, as the air is to the sun which enlightens it. For as the sun possesses light by its nature, and as the air is enlightened by sharing the sun's nature; so God alone is Being in virtue of His own Essence, since His Essence is His existence; whereas every creature has being by participation, so that its essence is not its existence. Therefore, as Augustine says (Gen. ad lit. iv, 12): "If the ruling power of God were withdrawn from His creatures, their nature would at once cease, and all nature would collapse." In the same work (Gen. ad lit. viii, 12) he says: "As the air becomes light by the presence of the sun, so is man enlightened by the presence of God, and in His absence returns at once to darkness."
Reply to Objection 1: "Being" naturally results from the form of a creature, given the influence of the Divine action; just as light results from the diaphanous nature of the air, given the action of the sun. Wherefore the potentiality to not-being in spiritual creatures and heavenly bodies is rather something in God, Who can withdraw His influence, than in the form or matter of those creatures.
Reply to Objection 2: God cannot grant to a creature to be preserved in being after the cessation of the Divine influence: as neither can He make it not to have received its being from Himself. For the creature needs to be preserved by God in so far as the being of an effect depends on the cause of its being. So that there is no comparison with an agent that is not the cause of 'being' but only of "becoming."
Reply to Objection 3: This argument holds in regard to that preservation which consists in the removal of corruption: but all creatures do not need to be preserved thus, as stated above.
Reply to Objection 4: The preservation of things by God is a continuation of that action whereby He gives existence, which action is without either motion or time; so also the preservation of light in the air is by the continual influence of the sun.
Objection 1: It would seem that God preserves every creature immediately. For God creates and preserves things by the same action, as above stated (A[1], ad 4). But God created all things immediately. Therefore He preserves all things immediately.
Objection 2: Further, a thing is nearer to itself than to another. But it cannot be given to a creature to preserve itself; much less therefore can it be given to a creature to preserve another. Therefore God preserves all things without any intermediate cause preserving them.
Objection 3: Further, an effect is kept in being by the cause, not only of its "becoming," but also of its being. But all created causes do not seem to cause their effects except in their "becoming," for they cause only by moving, as above stated (Q[45], A[3]). Therefore they do not cause so as to keep their effects in being.
On the contrary, A thing is kept in being by that which gives it being. But God gives being by means of certain intermediate causes. Therefore He also keeps things in being by means of certain causes.
I answer that, As stated above (A[1]), a thing keeps another in being in two ways; first, indirectly and accidentally, by removing or hindering the action of a corrupting cause; secondly, directly and "per se," by the fact that that on it depends the other's being, as the being of the effect depends on the cause. And in both ways a created thing keeps another in being. For it is clear that even in corporeal things there are many causes which hinder the action of corrupting agents, and for that reason are called preservatives; just as salt preserves meat from putrefaction; and in like manner with many other things. It happens also that an effect depends on a creature as to its being. For when we have a series of causes depending on one another, it necessarily follows that, while the effect depends first and principally on the first cause, it also depends in a secondary way on all the middle causes. Therefore the first cause is the principal cause of the preservation of the effect which is to be referred to the middle causes in a secondary way; and all the more so, as the middle cause is higher and nearer to the first cause.
For this reason, even in things corporeal, the preservation and continuation of things is ascribed to the higher causes: thus the Philosopher says (Metaph. xii, Did. xi, 6), that the first, namely the diurnal movement is the cause of the continuation of things generated; whereas the second movement, which is from the zodiac, is the cause of diversity owing to generation and corruption. In like manner astrologers ascribe to Saturn, the highest of the planets, those things which are permanent and fixed. So we conclude that God keeps certain things in being, by means of certain causes.
Reply to Objection 1: God created all things immediately, but in the creation itself He established an order among things, so that some depend on others, by which they are preserved in being, though He remains the principal cause of their preservation.
Reply to Objection 2: Since an effect is preserved by its proper cause on which it depends; just as no effect can be its own cause, but can only produce another effect, so no effect can be endowed with the power of self-preservation, but only with the power of preserving another.
Reply to Objection 3: No created nature can be the cause of another, as regards the latter acquiring a new form, or disposition, except by virtue of some change; for the created nature acts always on something presupposed. But after causing the form or disposition in the effect, without any fresh change in the effect, the cause preserves that form or disposition; as in the air, when it is lit up anew, we must allow some change to have taken place, while the preservation of the light is without any further change in the air due to the presence of the source of light.
Objection 1: It would seem that God cannot annihilate anything. For Augustine says (QQ. 83, qu. 21) that "God is not the cause of anything tending to non-existence." But He would be such a cause if He were to annihilate anything. Therefore He cannot annihilate anything.
Objection 2: Further, by His goodness God is the cause why things exist, since, as Augustine says (De Doctr. Christ. i, 32): "Because God is good, we exist." But God cannot cease to be good. Therefore He cannot cause things to cease to exist; which would be the case were He to annihilate anything.
Objection 3: Further, if God were to annihilate anything it would be by His action. But this cannot be; because the term of every action is existence. Hence even the action of a corrupting cause has its term in something generated; for when one thing is generated another undergoes corruption. Therefore God cannot annihilate anything.
On the contrary, It is written (Jer. 10:24): "Correct me, O Lord, but yet with judgment; and not in Thy fury, lest Thou bring me to nothing."
I answer that, Some have held that God, in giving existence to creatures, acted from natural necessity. Were this true, God could not annihilate anything, since His nature cannot change. But, as we have said above (Q[19], A[4]), such an opinion is entirely false, and absolutely contrary to the Catholic faith, which confesses that God created things of His own free-will, according to Ps. 134:6: "Whatsoever the Lord pleased, He hath done." Therefore that God gives existence to a creature depends on His will; nor does He preserve things in existence otherwise than by continually pouring out existence into them, as we have said. Therefore, just as before things existed, God was free not to give them existence, and not to make them; so after they are made, He is free not to continue their existence; and thus they would cease to exist; and this would be to annihilate them.
Reply to Objection 1: Non-existence has no direct cause; for nothing is a cause except inasmuch as it has existence, and a being essentially as such is a cause of something existing. Therefore God cannot cause a thing to tend to non-existence, whereas a creature has this tendency of itself, since it is produced from nothing. But indirectly God can be the cause of things being reduced to non-existence, by withdrawing His action therefrom.
Reply to Objection 2: God's goodness is the cause of things, not as though by natural necessity, because the Divine goodness does not depend on creatures; but by His free-will. Wherefore, as without prejudice to His goodness, He might not have produced things into existence, so, without prejudice to His goodness, He might not preserve things in existence.
Reply to Objection 3: If God were to annihilate anything, this would not imply an action on God's part; but a mere cessation of His action.
Objection 1: It would seem that something is annihilated. For the end corresponds to the beginning. But in the beginning there was nothing but God. Therefore all things must tend to this end, that there shall be nothing but God. Therefore creatures will be reduced to nothing.
Objection 2: Further, every creature has a finite power. But no finite power extends to the infinite. Wherefore the Philosopher proves (Phys. viii, 10) that, "a finite power cannot move in infinite time." Therefore a creature cannot last for an infinite duration; and so at some time it will be reduced to nothing.
Objection 3: Further, forms and accidents have no matter as part of themselves. But at some time they cease to exist. Therefore they are reduced to nothing.
On the contrary, It is written (Eccles. 3:14): "I have learned that all the works that God hath made continue for ever."
I answer that, Some of those things which God does in creatures occur in accordance with the natural course of things; others happen miraculously, and not in accordance with the natural order, as will be explained (Q[105], A[6]). Now whatever God wills to do according to the natural order of things may be observed from their nature; but those things which occur miraculously, are ordered for the manifestation of grace, according to the Apostle, "To each one is given the manifestation of the Spirit, unto profit" (1 Cor. 12:7); and subsequently he mentions, among others, the working of miracles.
Now the nature of creatures shows that none of them is annihilated. For, either they are immaterial, and therefore have no potentiality to non-existence; or they are material, and then they continue to exist, at least in matter, which is incorruptible, since it is the subject of generation and corruption. Moreover, the annihilation of things does not pertain to the manifestation of grace; since rather the power and goodness of God are manifested by the preservation of things in existence. Wherefore we must conclude by denying absolutely that anything at all will be annihilated.
Reply to Objection 1: That things are brought into existence from a state of non-existence, clearly shows the power of Him Who made them; but that they should be reduced to nothing would hinder that manifestation, since the power of God is conspicuously shown in His preserving all things in existence, according to the Apostle: "Upholding all things by the word of His power" (Heb. 1:3).
Reply to Objection 2: A creature's potentiality to existence is merely receptive; the active power belongs to God Himself, from Whom existence is derived. Wherefore the infinite duration of things is a consequence of the infinity of the Divine power. To some things, however, is given a determinate power of duration for a certain time, so far as they may be hindered by some contrary agent from receiving the influx of existence which comes from Him Whom finite power cannot resist, for an infinite, but only for a fixed time. So things which have no contrary, although they have a finite power, continue to exist for ever.
Reply to Objection 3: Forms and accidents are not complete beings, since they do not subsist: but each one of them is something "of a being"; for it is called a being, because something is by it. Yet so far as their mode of existence is concerned, they are not entirely reduced to nothingness; not that any part of them survives, but that they remain in the potentiality of the matter, or of the subject.