You are here
On the Eternity of the World
Summa Contra Gentiles, Book II, cc. 32-37
Chapter 32: Arguments of Those Who Wish to Demonstrate the World's Eternity from the Point of View of God
1. However, since many have held that the world has existed always and of necessity, and have attempted to demonstrate this, it remains for us to present their arguments, so as to show that they do not constitute a necessary demonstration of the world's eternity. First, we give the arguments taken from God's side of the matter; second, those taken from the point of view of the creature; third, those derived from a consideration of the mode of the production of things, according to which they are held to begin to exist anew.
2. On the part of God the following arguments are used in order to prove the eternity of the world.
3. Every agent which does not always act is moved through itself or by accident: through itself, as in the case of a fire which, not always burning, begins to burn either because it is newly lit or because it is for the first time placed in proximity to the fuel; by accident, as when an agent that moves an animal begins to move it by some new movement made in its regard, either from within, as an animal begins to be moved when it awakes after having digested its food, or from without, as when actions arise anew that lead to the initiation of some new action. Now, God is moved neither through Himself nor by accident, as we proved in Book I of this work. Therefore, God acts always in the same way. And by His action created things take their place in being. Hence, creatures always have been.
4. Again, an effect proceeds from its efficient cause through the latter's action. But God's action is eternal; otherwise, from being an agent potentially He would become an agent actually; and He would have to be actualized by some prior agent ‒which is impossible. Therefore, the things created by God have existed from eternity.
5. And again. Given a sufficient cause, its effect must be granted. For if, given the cause, it were still unnecessary to grant its effect, it would then be possible that the effect should be and not be; the sequence from cause to effect will in that case be only possible. But that which is possible needs something to make it actual. Some cause, therefore, will have to be posited in order to do this; thus, the first cause was not sufficient. God, however, is the sufficient cause of the production of creatures; otherwise, He would not be a cause; rather, He would be in potentiality to a cause, since in that case He would become a cause by the addition of something. But this is clearly impossible. Since, then, God has existed from eternity, it seems to follow necessarily that the creature also has existed from eternity.
6. Also, a voluntary agent delays in carrying out its intention only because of something expected but not yet present, and this sometimes is in the agent itself, as when complete competency to do something, or the removal of an impediment to one's power, is waited for; while sometimes this anticipated thing is outside the agent, as when one awaits a person in whose presence an action is to be done, or at any event when one looks forward to the presence of an opportune moment that has not yet arrived. For, if the will be perfectly equipped, the power acts at once, unless there be a defect in it; at the will's command the movement of a limb follows immediately, if no defect exists in the motive power carrying out the movement. And from this we see that when one wills to do something and it is not done at once, this failure must be due either to a defect in the power, of which defect one awaits the removal, or to the fact that the will is not perfectly equipped to do this thing. By the will being perfectly equipped I mean that it wills to do something absolutely, in every respect; whereas the will is imperfectly equipped when one does not will absolutely to do a thing, but on the condition that something exist which is not yet present or that a present obstacle be removed. It is certain however, that God has willed from eternity the existence of whatever He now wills to exist, for no new movement of will can possibly accrue to Him. Nor could any defect or obstacle stand in the way of His power, nor could anything else be looked for as cause of the universal production of creatures, since nothing besides Him is uncreated, as we have proved above. Therefore, it seems necessary to conclude that God brought creatures into being from all eternity.
7. Moreover, an intellectual agent chooses one thing in preference to another only because of the superiority of the one over the other. But, where there is no difference, there can be no superiority, so that in the absence of difference there is no choice of the one rather than of the other. And on this account, no action will proceed from an agent equally indifferent to each of two alternatives, any more than from matter; for a potentiality of this kind is like that of matter. Now, there can be no difference between non-being and non-being. Therefore, one non-being is not preferable to another non-being. But outside the total universe of created things nothing whatever exists except the divine eternity. In nothingness, however, no difference of moments can possibly be assigned, so that a thing should be made in one moment rather than in another. Nor is there any difference of moments in eternity, the whole of which is, as was shown in Book I, uniform and simple. It therefore follows that God's will is indifferent as concerns the production of the creature throughout all eternity. Accordingly, His will is either that the creature should never be established within His eternity, or that it should always have been so. The former clearly is not the case, for it is evident that creatures were originated and established by His will. It follows with apparent necessity that the creature has always existed.
8. Furthermore, things directed to an end receive their necessity from that end; especially is this true of things done voluntarily. Therefore, if the end remains the same, it follows that the things ordered to it remain the same or are produced in the same way, unless there arises a new relation between them and the end. Now, the end of creatures issuing forth from the divine will is the divine goodness, which alone can be the end of the divine will. From the fact that the divine goodness, throughout all eternity, is unchangeable in itself and in relation to the divine will, it would seem to follow that creatures are in the same manner brought into being by God's will throughout all eternity. For it cannot be said that some new relation to the end accrued to them, if they are held to have been absolutely non-existent prior to a particular time from which they are supposed to have begun to be.
9. Since the divine goodness is maximally perfect, it is said that all things issued from God on account of His goodness, but not in such a way that something accrued to Him from creatures; rather, this is said because it is of the essence of goodness to communicate itself as far as possible, and by so doing goodness itself is manifested. Now, since all things partake of God's goodness so far as they have being, the more enduring they are, so much the more do they participate in His goodness. This is why the perpetual being of a species is called a divine being. [cf. Aristotle, De anima, II,4.] The divine goodness, however, is in finite, so that it is proper to it to communicate itself in an infinite manner, not in some limited time only. Therefore, it seems to belong to the divine goodness that some created things should have existed from eternity.
10. These, then, are the arguments, taken from God's side of the question, which seem to show that creatures have existed always.
Chapter 33: Arguments of Those Who Wish to Prove the Eternity of the World from the Standpoint of Creatures
1. There are also the following arguments, taken from the point of view of creatures, which seemingly arrive at the same conclusion.
2. Things having no potentiality to non-being cannot possibly fail to exist. Now, in certain created things there is no potentiality to non-being. For there can be potentiality to non-being only in those things which possess matter subject to contrariety; for potentiality tobeing and non-being is potentiality to privation and form, the subject of which is matter; and privation is always connected with the contrary form, since matter cannot possibly exist without any form at all. But some creatures, wherein there is no matter subject tocontrariety, do exist, either because they are completely without matter, as intellectual substances are ‒this we will show laterl‒or because they have no contrary opposite, as with the heavenly bodies ‒and this is proved by their movement, which has no contrary. It is, then, impossible for certain creatures not to exist; therefore, they must always exist.
3. Moreover, each and every thing continues in being in proportion to its power of being ‒except by accident, as in things caused to perish by violence. But there are some creatures endowed with the power of existing, not for any limited time, but forever; the heavenly bodies, for instance, and intellectual substances, which are imperishable because they have no contrary. It is therefore proper to these things to exist always. On the other hand, that which begins to be does not exist always. Therefore, an existential beginning does not pertain to imperishable or incorruptible things.
4. Furthermore, whenever something begins to be moved for the first time, either the mover, or the moved, or both, must needs exist in a different state now, while there is movement, than before, when no movement existed. For there is a certain condition or relation in the mover to the thing moved, as a result of which it moves actually; and the new relation does not arise without a change either in both orat least in one or other of the extremes related. But that thing is moved whose condition of existence is different now than it was before. Therefore, prior to the newly initiated movement, another movement must take place either in the movable thing or in the mover; so that every movement is either eternal or is preceded by another movement. Therefore, motion has always existed, and so, also, have things movable. Hence, creatures have always existed. For God is wholly immutable, as we proved in Book I of this work.
5. Again, every agent which engenders its like intends to preserve perpetual being in the species, for existence cannot be so maintained in the individual. Now, it is impossible that natural desire should be futile. The species of generable things, therefore, must be perpetual.
6. And again, if time is everlasting, so also must motion be; for time "is the number of motion." [cf. Aristotle, Physics, IV,11] And, consequently, things movable must be perpetual, since motion is the "act of the movable." [cf. Aristotle, Physics, III,2] But time must be everlasting. For time cannot be known to exist without the now, any more than a line without a point. But the now is always "the end of the past and the beginning of the future," [cf. Aristotle, Physics, IV,13] for this is the definition of the now. Thus, every given now has time preceding it and following it, so that no now can be either first or last. It remains that mobile things, which created substances are, exist from eternity.
7. Also, it is necessary either to affirm or to deny. If, therefore, a thing's existence is affirmed as a result of denying it, then that thing must exist always. Now, time is such a thing. For to suppose that time did not always exist is to think of it as not existing prior to existing; and, similarly, if time will not exist always, its non-existence must succeed its existence. But if time does not exist, there can be no before and after in duration; for "the number of before and after is time." [cf. Aristotle, Physics, IV,11] And thus, time must have existed before it began to be and will continue to exist after it has ceased to be. Time is, therefore, necessarily eternal. But time is an accident, and an accident cannot be without a subject. Now, God, who is above time, is not the subject of this accident, for He is altogether immutable, as we proved in Book I of this work. It remains that some created substance is eternal.
8. Many propositions, moreover, are of such nature that he who denies them must posit them; for example, whoever denies that truth exists posits the existence of truth, for the denial which he puts forward he posits as true. The same is true of one who denies the principle that contradictories are not simultaneous; for, by denying this, he asserts that the negation which he posits is true and that the opposite affirmation is false, and thus that both are not true of the same thing. Therefore, if a thing that is affirmed by being denied must, as we have just shown, exist always, then the aforesaid propositions, and all that follow from them, are everlasting. But these propositions are not God. It is, therefore, necessary that something besides God be eternal.
9. These arguments, then, and others of like nature, can be taken from the standpoint of created things in order to prove that the latter have existed always.
Chapter 34: Arguments to Prove the Eternity of the World from the Point of View of the Making [of Things]
1. In order to establish the same conclusion, this time from the side of the making itself, other arguments also can be adduced, such as the following.
2. That which is asserted universally, by everyone, cannot possibly be totally false. For a false opinion is a kind of infirmity of the understanding, just as a false judgment concerning a proper sensible happens as the result of a weakness of the sense power involved. But defects, being outside the intention of nature, are accidental. And nothing accidental can be always and in all things; the judgment about savors given by every tasting cannot be false. Thus, the judgment uttered by everyone concerning truth cannot be erroneous. "Now, it is the common opinion of all the philosophers that nothing arises from what is not." [cf. Aristotle, Physics, I,4]
This opinion, therefore, must be true; so that if a thing is made it must needs be made from something; and if the latter, also, is made, then it, too, must be made from something else. But this process cannot go on to infinity, since in that case no generation of anything would be completed; it is impossible to pass through an infinite number of things. It is therefore necessary to arrive at a first thing that was not made. But any and everything which has not always existed must be made. Consequently, that being from which all things were first made, must be everlasting. Yet this is not God, because He cannot be the matter of anything, as we proved in Book I of this work. Thus, it follows that something besides God is eternal, namely, prime matter.
3. Moreover, if a thing does not exist in the same way now as it did before, then in some respect it must be changed, for to be moved [or changed] is not to exist in the same state now as before. But everything that begins to exist anew is not now as it was before; hence, the reason for this must be that some motion or change has occurred. But every motion or change is in a subject, for it is "the act of the movable." [cf. Aristotle, Physics, III,2] Now, since motion precedes that which is made by it, for it terminates in the latter, it follows that a movable subject must exist prior to anything made. And since to proceed to infinity in this matter is impossible, we must come to a first subject not newly originated but always existent.
4. Then, too, in the case of a thing that begins to be anew, it was possible, before it existed, that it would exist; otherwise, it was impossible for it to be, and necessary for it not to be; so that it would always have been a non-entity and would never have begun to be. But that which is possibly existent is potentially a subject of being. Therefore, antecedently to everything which begins to exist de novo, there must be a subject which is potentially a being. And since an infinite regress is here impossible, we must affirm the existence of a primary subject which did not begin to be de novo.
5. Furthermore, no permanent substance exists while it is being made, for it is made in order that it may be; so, it would not be made if it existed already. But, while it is being made, something must exist which is the subject of the making; for, since making is an accident, there can be no making without a subject. Thus, whatever is made has some pre-existing subject. And since this cannot go on indefinitely, it follows that the first subject was not made, but is everlasting; and it follows, also, that something besides God is eternal, because He cannot be the subject of making or of movement.
6. These, then, are the arguments through adhering to which, as though they were demonstrations, some people say that created things must always have existed; in so saying they contradict the Catholic faith, which affirms that nothing besides God has always existed, but that all things, save the one eternal God, have had a beginning.
Chapter 35: Solution of the Foregoing Arguments, and First of Those Taken from the Standpoint of God
1. It remains for us to show that the arguments proposed above issue in no necessary conclusions. First, let us consider those taken from the agent's point of view.
2. God need not be moved either essentially or accidentally if His effects begin to exist anew, as the first argument would have it. For the newness of an effect can indicate change on the agent's part inasmuch as it does manifest newness of action; a new action cannot possibly be in the agent unless the latter is in some way moved, at least from inaction to action. But the newness of an effect produced by God does not demonstrate newness of action in Him, since His action is His essence, as we have proved above. Neither, therefore, can newness of effect prove change in God the agent.
3. Nor, if the action of the first agent is eternal, does it follow that His effect is eternal, as the second argument concludes. For we have already shown in this Book that God acts voluntarily in the production of things, but not in such fashion that there be some other intermediate action of His, as in us the action of the motive power intervenes between the act of the will and the effect, as we have also previously shown. On the contrary, God's act of understanding and willing is, necessarily, His act of making. Now, an effect follows from the intellect and the will according to the determination of the intellect and the command of the will. Moreover, just as the intellect determines every other condition of the thing made, so does it prescribe the time of its making; for art determines not only that this thing is to be such and such, but that it is to be at this particular time, even as a physician determines that a dose of medicine is to be drunk at such and such a particular time, so that, if his act of will were of itself sufficient to produce the effect, the effect would follow anew from his previous decision, without any new action on his part. Nothing, therefore, prevents our saying that God's action existed from all eternity, whereas its effect was not present from eternity, but existed at that time when, from all eternity, He ordained it.
4. From this we see also that, although God is the sufficient cause of bringing things into being, it is not necessary to hold that because He is eternal His effect is eternal, as the third argument maintained. Given a sufficient cause, its effect is given, too, but not an effect that does not belong to the cause for this would result from the insufficiency of the cause: as if a hot thing, for example, failed to give heat. Now, the will's proper effect is the being of that which it wills; and if something else were to be than what the will determines, this would be an effect not proper to the cause but foreign to it. But, as we have said, just as the will wills this thing to be such and such, so does it will it to be at such and such a time. Hence for the will to be a sufficient cause it is not necessary that the effect should exist when the will exists, but at that time when the will has ordained its existence. But with things that proceed from a cause acting naturally, the case is different. For, as nature is, so is its action; hence, given the existence of the cause, the effect must necessarily follow. On the other hand, the will acts in keeping not with the manner of its being, but of its intention. So, then, just as the effect of a natural agent follows the being of the agent, if the latter is sufficient, so the effect of a voluntary agent follows the mode of his purpose.
5. Moreover, what has been said makes it clear that, contrary to the fourth argument, the effect of God's will was not delayed, although having been always willed, the effect was not itself always existent. For within the scope of God's will fall not only the existence of His effect but also the time of its existence. Therefore, this thing willed, namely, that a creature should exist at a certain time, is not delayed, for the creature began to exist at that time which God appointed from all eternity.
6. Prior to the initial existence of the totality of created being there is no diversity of parts of any duration, as was supposed in the fifth argument. For nothingness has neither measure nor duration. Now, God's duration, which is eternity, does not have parts, but is utterly simple, without before or after; since God is immovable, as we have shown in Book I of this work. Therefore, the beginning of the whole of creation is not to be thought of in comparison to any diverse parts designated in some pre-existing measure, to which parts the beginning of creatures can stand in similar or dissimilar relations, so that there would have to be a reason in the agent why he brought the creature into being in this designated part of that duration rather than at some other preceding or subsequent point. Such a reason would be required if, beside the totality of created being, there existed some duration divisible into parts, as is the case in particular agents, which produce their effects in time, but do not produce time itself . God, however, brought into being both the creature and time together. In this case, therefore, the reason why He produced them now and not before does not have to be considered but only why He did not produce them always. A comparison with place will make this point clear. Particular bodies are brought into being not only at a definite time, but also in a definite place; and since the time and the place in which they are involved are extrinsic to them, there must be a reason why they are produced in this place and time rather than in another. On the other hand, outside the entire heavens there is no place, the universal place of all things being produced together with it; so that there is no reason for considering why the heaven was established in being here and not there. And because they thought that such a reason ought to be sought for, some have fallen into the error of attributing infinity to bodily things. Similarly, outside the entire universe of creatures there is no time, time having been produced simultaneously with that universe; hence, we do not have to look for the reason why it was produced now and not before, so as to be led to concede the infinity of time; we have only to ask why it was not always produced, or why it was produced after not being or with some beginning.
7. Now, in order to inquire into this matter, the sixth argument was adduced from the point of view of the end, which alone can introduce necessity into things done voluntarily. But the only possible end of God's will is His own goodness; and He does not act for the sake of bringing this end into being, as the craftsman acts in order to produce his handiwork. For God's goodness is eternal and immutable, so that nothing can accrue to Him. Nor can it be said that God acts for His own betterment. Nor does He act in order to obtain this end for Himself, as a king fights in order to gain possession of a city; for God is His own goodness. We therefore conclude that God acts for an end inasmuch as He produces an effect so that it may participate in His end. Therefore, in producing a thing for the sake of an end, in this sense, the uniform relation of the end to the agent is not to be thought of as the reason for His work being eternal; on the contrary, the thing to be attended to is the relation of the end to the effect brought forth on account of the end in order that the effect be produced in such a manner as to be most fittingly ordained to that end. Hence, from the fact that the relation of the end to the agent is uniform, we cannot conclude that the effect is eternal.
8. Nor, as the seventh argument seemed to imply, is it necessary that God's effect should have always existed because it would then be more fittingly directed to its end. On the contrary, by not having existed always, it is more fittingly directed to its end. For every agent that produces an effect in participation of its own form intends to produce its own likeness in that effect. Thus, to produce the creature in participation of His own goodness was becoming to God's will, for by its likeness to Him the creature might show forth His goodness. But this representation cannot be in terms of equality, in the manner in which a univocal effect represents its cause ‒so that eternal effects would have to be produced by the divine goodness. Rather, this representation is in keeping with the way in which the transcendent is manifested by that which is transcended. Now, the transcendence of God's goodness over the creature is shown most of all by the fact that creatures have not always existed. For this makes it perfectly clear that all things other than God have Him as the author of their being; and that His power is not fettered to the production of those effects, as nature is to natural effects; and, consequently, that He is a voluntary and intelligent agent. (Some, assuming the eternity of creatures, have asserted views contrary to these.)
9. There is, then, nothing from the agent's side of the question that compels us to maintain the eternity of creatures.
Chapter 36: Solution of the Arguments Proposed from the Point of View of the Things Made
1. Likewise, there is nothing on the part of creatures that induces us necessarily to affirm their eternity.
2. The necessity of being that we find in creatures, whence the first argument about this question is drawn, is a necessity of order, as we have previously shown. But, as we proved above, a necessity of order does not compel the subject in which a necessity of this kind is present to exist always. For, although the substance of the heaven has necessity with respect to being, in virtue of the fact that it lacks potentiality to non-being, this necessity nevertheless is consequent upon its substance. Hence, once its substance has been established in being, this necessity entails the impossibility of not-being; but if we consider the production of its very substance, it does not entail the impossibility of the heaven's not being at all.
3. Likewise, the power of existing always, whereon the second argument is based, presupposes the production of the substance; so that, where the point at issue is the production of the substance of the heaven, this power cannot be a sufficient proof of the eternity of that substance.
4. Nor does the argument brought up next compel us to assert the eternity of motion. For what we have said already makes it clear that, without any change in God the agent, He can enact something new that is not eternal. But, if something can be done by Him anew, it is evidently possible, also, for something to be moved by Him anew. For newness of motion follows upon the decision of the eternal will of God, that motion be not always in existence.
5. Then, too, the intention of natural agents to perpetuate the species ‒this was the starting point of the fourth argument‒ presupposes that natural agents already exist. Hence, this argument is relevant only to natural things already brought into being; where it is a question of the production of things, it has no place. But the question, whether it is necessary to hold that the engendering of things will go on for ever, will be dealt with later.
6. Furthermore, the fifth argument, drawn from a consideration of time, supposes the eternity of motion rather than proves it. For, as Aristotle teaches, [cf. Aristotle, Physics, IV,5] the before and after and the continuity of time follow upon the before and after and the continuity of motion. Clearly, then, the same instant is the beginning of the future and the end of the past because some assigned point in motion is the beginning and the end of the diverse parts of motion. So, not every instant need be of this kind unless we think of every assignable poin in time as existing between a before and an after in movement; and this is to suppose that movement is eternal. On the other hand if we held that motion is not eternal, we can say that the first instant of time is the beginning of the future and the terminus of no time past. Nor, simply because a line, wherein some point is a beginning and not an end, is fixed and not flowing, is it incompatible with time's successiveness if we suppose a now that is a beginning and not an end; for even in some particular movement, which is not stationary either, but transitory, it is possible to designate a point which is a beginning only and not an end; otherwise, all movement would be perpetual; and this is impossible.
7. True, if time had a beginning, we are supposing its non existence to precede its existence. But the supposition of time's non-existence does not compel us to assert its existence, as the sixth argument would have it. For the before that we speak of as preceding time implies nothing temporal in reality, but only in our imagination. Indeed, when we say that time exists after not existing, we mean that there was no time at all prior to this designated now; even so, when we declare that above the heaven there is nothing, we are not implying the existence of a place outside the heaven which can be said to be above in relation to it, but that there is no place at all above it. In either case, the imagination can add a certain dimension to the already existing thing; and just as this is no reason for attributing infinite quantity to a body, as is said in Physics III, [cf. Aristotle, Physics, III, 6] so neither does it justify the supposition that time is eternal.
8. The truth of propositions whose denial entails their affirmation‒and this was the starting point of the seventh argument‒possesses the necessity of that order which obtains between predicate and subject. By such necessity, therefore, a thing is not compelled to exist everlastingly, except perhaps the divine intellect, in whom all truth is rooted, as was shown in Book I of this work.
9. It is therefore clear that the arguments adduced from the point of view of creatures do not oblige us to maintain that the world is eternal.
Chapter 37: Solution of the Arguments Taken from the Point of View of the Making of Things
1. Lastly, we must show that no argument drawn from the standpoint of the making of things can necessitate that same conclusion.
2. The common opinion of the philosophers, on which the first argument was based, namely, that from nothing comes nothing, is true as regards that particular making which they had in mind. Since our knowledge originates in sense perception, which is concerned with singular things, the progress of human thought has been from particular to universal considerations. That is why those who sought the principle of things considered only particular makings of things, inquiring how this particular fire or stone comes to be. And so those who came first, considering the making of things in a more extrinsic fashion than they needed to, claimed that a thing is made only as concerns certain accidental dispositions, such as rarity, density, and the like, and consequently they said that to be made was nothing else than to be altered; and this they held because it was their understanding that each and every thing was made from a being actually existing. But later thinkers, considering the making of things from a more intrinsic point of view, advanced to the problem of the making of things in terms of their substance; and they maintained that from an actually existing being a thing need be made only in an accidental respect, but that from a being potentially existent it is made in essential fashion. But this making, namely, of a being from any being whatever, is that of a particular being: one that is made inasmuch as it is this being, a man or a fire, for example, but not inasmuch as it is, universally, because there was previously existent being that is transformed into this being. Entering more deeply into the problem of the origin of things, philosophers came at last to consider the procession of all created being from one first cause: a truth made evident by arguments previously proposed. Now, in this procession of all being from God it is impossible for anything to be made from some other preexisting thing; otherwise, this procession would not consist in the making of all created being.
3. Now, the first philosophers of nature, who shared the commonly received opinion that nothing is made from nothing, did not attain to the idea of such a making as this. Or, if any of them conceived of it, they did not consider it making properly speaking, since the word making implies motion or change, whereas in the origination of all being from one first being, the transmutation of one being into another is, as we have shown, inconceivable. And on this account it is the business not of the philosopher of nature to consider that origination, but of the metaphysician, who considers universal being and things existing apart from motion. Nevertheless, in virtue of a certain likeness we transfer the word making even to that origination of things, saying that anything at all whose essence or nature originates from something else is made.
4. From this we see that the second argument, based on the concept of motion, is also inconclusive. For creation can be called a change only in a metaphorical sense, that is, only so far as the created thing is thought of as having being after not being, even as with things not mutually transformed we say that one comes to be from another simply because one succeeds the other; for instance, that day comes from night. Now, since that which in no way exists is not in any particular state, the idea of motion used in the argument does not warrant the conclusion that, when a thing begins to be, it is in another state now than it was before.
5. Whence it is also clear that, contrary to the third argument, no passive potentiality need precede the existence of all created being. Such a necessity obtains in the case of things that come into being by way of motion, for motion is the act of a thing existing potentially. [cf. Aristotle, Physics, III,1] But before a created thing existed, its existence was possible, in virtue of the power of its agent, by which also it began to be. Or that thing was possible on account of the relationship between the terms involved, wherein no incompatibility is found; and this is possibility "according to no potentiality," as Aristotle states in Metaphysics V. [cf. Aristotle, Metaphysics, V,12] For the predicate, act of being, is not incompatible with the subject, world or man, as commensurable is incompatible with diameter. It therefore follows that the existence of the world or of man is not impossible, and, consequently, that before they actually existed their existence was possible, even in the absence of all potentiality. On the other hand, things produced by way of motion must be previously possible by virtue of a passive potentiality; and when Aristotle uses this argument in Metaphysics VII it is to these things that he refers. [cf. Aristotle, Metaphysics, VII,7]
6. Moreover, from what has been said it is clear that the fourth argument likewise misses the mark. For, in things made by way of motion, to be made and to be are not simultaneous, because the production of such things involves succession. But in things that are not made by way of motion, the making does not precede the being.
7. In the light of all this, then, it is clear that nothing stands in the way of one's holding that the world has not always existed‒a truth which the Catholic faith affirms: "In the beginning God created heaven and earth" (Gen. 1:1); and in the Book of Proverbs (8: 22) it is said of God: "Before He made anything from the beginning..."
Summa contra Gentiles, Book II, cc. 32-37, translated by James F. Anderson (London: University of Notre Dame Press, 1975) pp. 92-111.