Summa Theologica, Part I (Prima Pars) From the Complete...

Obj. 7: Further, if the world was eternal, generation also was eternal. Therefore one man was begotten of another in an infinite series. But the father is the efficient cause of the son (Phys. ii, text 5). Therefore in efficient causes there could be an infinite series, which is disproved (Metaph. ii, text 5).

Obj. 8: Further, if the world and generation always were, there have been an infinite number of men. But man's soul is immortal: therefore an infinite number of human souls would actually now exist, which is impossible. Therefore it can be known with certainty that the world began, and not only is it known by faith.

On the contrary, The articles of faith cannot be proved demonstratively, because faith is of things "that appear not" (Heb. 11:1). But that God is the Creator of the world: hence that the world began, is an article of faith; for we say, "I believe in one God," etc. And again, Gregory says (Hom. i in Ezech.), that Moses prophesied of the past, saying, "In the beginning God created heaven and earth": in which words the newness of the world is stated. Therefore the newness of the world is known only by revelation; and therefore it cannot be proved demonstratively.

I answer that, By faith alone do we hold, and by no demonstration can it be proved, that the world did not always exist, as was said above of the mystery of the Trinity (Q. 32, A. 1). The reason of this is that the newness of the world cannot be demonstrated on the part of the world itself. For the principle of demonstration is the essence of a thing. Now everything according to its species is abstracted from "here" and "now"; whence it is said that universals are everywhere and always. Hence it cannot be demonstrated that man, or heaven, or a stone were not always. Likewise neither can it be demonstrated on the part of the efficient cause, which acts by will. For the will of God cannot be investigated by reason, except as regards those things which God must will of necessity; and what He wills about creatures is not among these, as was said above (Q. 19, A. 3). But the divine will can be manifested by revelation, on which faith rests. Hence that the world began to exist is an object of faith, but not of demonstration or science. And it is useful to consider this, lest anyone, presuming to demonstrate what is of faith, should bring forward reasons that are not cogent, so as to give occasion to unbelievers to laugh, thinking that on such grounds we believe things that are of faith.

Reply Obj. 1: As Augustine says (De Civ. Dei xi, 4), the opinion of philosophers who asserted the eternity of the world was twofold. For some said that the substance of the world was not from God, which is an intolerable error; and therefore it is refuted by proofs that are cogent. Some, however, said that the world was eternal, although made by God. For they hold that the world has a beginning, not of time, but of creation, so that in a certain hardly intelligible way it was always made. "And they try to explain their meaning thus (De Civ. Dei x, 31): for as, if the foot were always in the dust from eternity, there would always be a footprint which without doubt was caused by him who trod on it, so also the world always was, because its Maker always existed." To understand this we must consider that the efficient cause, which acts by motion, of necessity precedes its effect in time; because the effect is only in the end of the action, and every agent must be the principle of action. But if the action is instantaneous and not successive, it is not necessary for the maker to be prior to the thing made in duration as appears in the case of illumination. Hence they say that it does not follow necessarily if God is the active cause of the world, that He should be prior to the world in duration; because creation, by which He produced the world, is not a successive change, as was said above (Q. 45, A. 2).

Reply Obj. 2: Those who would say that the world was eternal, would say that the world was made by God from nothing, not that it was made after nothing, according to what we understand by the word creation, but that it was not made from anything; and so also some of them do not reject the word creation, as appears from Avicenna (Metaph. ix, text 4).

Reply Obj. 3: This is the argument of Anaxagoras (as quoted in Phys. viii, text 15). But it does not lead to a necessary conclusion, except as to that intellect which deliberates in order to find out what should be done, which is like movement. Such is the human intellect, but not the divine intellect (Q. 14, AA. 7, 12).

Reply Obj. 4: Those who hold the eternity of the world hold that some region was changed an infinite number of times, from being uninhabitable to being inhabitable and "vice versa," and likewise they hold that the arts, by reason of various corruptions and accidents, were subject to an infinite variety of advance and decay. Hence Aristotle says (Meteor. i), that it is absurd from such particular changes to hold the opinion of the newness of the whole world.

Reply Obj. 5: Even supposing that the world always was, it would not be equal to God in eternity, as Boethius says (De Consol. v, 6); because the divine Being is all being simultaneously without succession; but with the world it is otherwise.

Reply Obj. 6: Passage is always understood as being from term to term. Whatever bygone day we choose, from it to the present day there is a finite number of days which can be passed through. The objection is founded on the idea that, given two extremes, there is an infinite number of mean terms.

Reply Obj. 7: In efficient causes it is impossible to proceed to infinity per se—thus, there cannot be an infinite number of causes that are per se required for a certain effect; for instance, that a stone be moved by a stick, the stick by the hand, and so on to infinity. But it is not impossible to proceed to infinity accidentally as regards efficient causes; for instance, if all the causes thus infinitely multiplied should have the order of only one cause, their multiplication being accidental, as an artificer acts by means of many hammers accidentally, because one after the other may be broken. It is accidental, therefore, that one particular hammer acts after the action of another; and likewise it is accidental to this particular man as generator to be generated by another man; for he generates as a man, and not as the son of another man. For all men generating hold one grade in efficient causes—viz. the grade of a particular generator. Hence it is not impossible for a man to be generated by man to infinity; but such a thing would be impossible if the generation of this man depended upon this man, and on an elementary body, and on the sun, and so on to infinity.

Reply Obj. 8: Those who hold the eternity of the world evade this reason in many ways. For some do not think it impossible for there to be an actual infinity of souls, as appears from the Metaphysics of Algazel, who says that such a thing is an accidental infinity. But this was disproved above (Q. 7, A. 4). Some say that the soul is corrupted with the body. And some say that of all souls only one will remain. But others, as Augustine says [*Serm. xiv, De Temp. 4, 5; De Haeres., haeres. 46; De Civ. Dei xii. 13], asserted on this account a circuit of souls—viz. that souls separated from their bodies return again thither after a course of time; a fuller consideration of which matters will be given later (Q. 75, A. 2; Q. 118, A. 6). But be it noted that this argument considers only a particular case. Hence one might say that the world was eternal, or at least some creature, as an angel, but not man. But we are considering the question in general, as to whether any creature can exist from eternity. _______________________

Objection 1: It would seem that the creation of things was not in the beginning of time. For whatever is not in time, is not of any part of time. But the creation of things was not in time; for by the creation the substance of things was brought into being; and time does not measure the substance of things, and especially of incorporeal things. Therefore creation was not in the beginning of time.

Obj. 2: Further, the Philosopher proves (Phys. vi, text 40) that everything which is made, was being made; and so to be made implies a "before" and "after." But in the beginning of time, since it is indivisible, there is no "before" and "after." Therefore, since to be created is a kind of "being made," it appears that things were not created in the beginning of time.

I answer that, The words of Genesis, "In the beginning God created heaven and earth," are expounded in a threefold sense in order to exclude three errors. For some said that the world always was, and that time had no beginning; and to exclude this the words "In the beginning" are expounded—viz. "of time." And some said that there are two principles of creation, one of good things and the other of evil things, against which "In the beginning" is expounded—"in the Son." For as the efficient principle is appropriated to the Father by reason of power, so the exemplar principle is appropriated to the Son by reason of wisdom, in order that, as it is said (Ps. 103:24), "Thou hast made all things in wisdom," it may be understood that God made all things in the beginning—that is, in the Son; according to the word of the Apostle (Col. 1:16), "In Him"—viz. the Son—"were created all things." But others said that corporeal things were created by God through the medium of spiritual creation; and to exclude this it is expounded thus: "In the beginning"—i.e. before all things—"God created heaven and earth." For four things are stated to be created together—viz. the empyrean heaven, corporeal matter, by which is meant the earth, time, and the angelic nature.

Reply Obj. 2: This saying of the Philosopher is understood "of being made" by means of movement, or as the term of movement. Because, since in every movement there is "before" and "after," before any one point in a given movement—that is, whilst anything is in the process of being moved and made, there is a "before" and also an "after," because what is in the beginning of movement or in its term is not in "being moved." But creation is neither movement nor the term of movement, as was said above (Q. 45, AA. 2, 3). Hence a thing is created in such a way that it was not being created before.

Reply Obj. 3: Nothing is made except as it exists. But nothing exists of time except "now." Hence time cannot be made except according to some "now"; not because in the first "now" is time, but because from it time begins. _______________________