Summa contra Gentiles2.38 Chapter XXXVIII. Arguments by which some endeavour to prove that the world is not eternal

Now there are some arguments brought forward by certain people to prove that the world was not always: they are taken from the following.

For it has been proved that God is the cause of all things. But a cause must precede in duration the things made by its action.

Again. Since all being is created by God, it cannot be said to be made from some being, so that it must be made from nothing, and consequently has being after non-being.

Also, because it is not possible to pass by an infinite number of things. Now if the world were always, an infinite number of things would have now been passed by: since what is past, is passed by, and if the world was always, there is an infinite number of days or an infinite number of solar revolutions.

Further. It follows that an addition is made to the infinite, since every day something is added to the past days or revolutions.

Moreover. It follows that it is possible to go on to infinity in efficient causes, if there was always generation; and we are bound to admit this latter if the world was always: because the son’s cause is his father, and another man is the latter’s father, and so on indefinitely.

Again. It will follow that there is an infinite number of things: namely the immortal souls of an infinite number of men.

Now since these arguments do not conclude of absolute necessity, although they are not devoid of probability, it is enough merely to touch upon them, lest the Catholic faith seem to be founded on empty reasonings, and not, as it is, on the most solid teaching of God. Wherefore it seems right that we should indicate how those arguments are met by those who asserted the eternity of the world.

For the first statement that an agent necessarily precedes the effect brought about by its operation, is true of those things which act by movement, because the effect is not until the movement is ended, and the agent must necessarily exist even when the movement begins. On the other hand in those things which act instantaneously, this is not necessary: thus as soon as the sun reaches the point of the East, it enlightens our hemisphere.

Also, that which is said in the second place is of no avail. For in order to contradict the statement. Something is made from something, if this be not granted, we must say Something is not made from something, and not. Something is made from nothing, except in the sense of the former: whence we cannot conclude that it is made after not being.

Again, the third argument is not cogent. For though the infinite in act be impossible, it is not impossible in succession, since any given infinite taken in this sense is finite. Hence each of the preceding revolutions could be passed by, since it was finite. But in all of them together, if the world had been always, there would be no first revolution. Wherefore there would be no passing through them, because this always requires two extremes.

Again, the fourth argument put forward is weak, gor nothing hinders the infinite receiving an addition on the side on which it is finite. Now supposing time to be eternal, it follows that it is infinite anteriorly but finite posteriorly, since the present is the term of the past.

Nor is the argument cogent which is given in the fifth place. For it is impossible, according to philosophers, to have an infinite number of active causes which act together simultaneously: because the effect would have to depend on an infinite number of simultaneous actions. Such are causes that are per se infinite, because their infinity is required for their effect. On the other hand in causes that do not act simultaneously, this is not impossible, according to those who assert that generation has always been. And this infinity is accidental to the causes, for it is accidental to the father of Socrates that he is another man’s son or not. Whereas it is not accidental to the stick forasmuch as it moves the stone, that it be moved by the hand, since it moves forasmuch as it is moved.

The objection taken from souls is more difficult. And yet the argument is not of much use, since it takes many things for granted. For some of those who maintained the eternity of the world, asserted that human souls do not survive the body. Some said that of all souls there survives only the separate intellect, or the active intellect according to some, or even the passive intellect according to others. Some have held a kind of rotation in souls, saying that the same souls after several centuries return to bodies. And some do not consider it incongruous that there should be things actually infinite in those which have no order.

Nevertheless one may proceed to prove this more efficiently from the end of the divine will, as we have indicated above. For the end of God’s will in the production of things, is His goodness as manifested in His effects. Now God’s might and goodness are especially made manifest in that things other than Himself were not always. For the fact that they have not always been clearly shows that other things beside Himself have their being from Him. It also shows that He does not act by a necessity of His nature, and that His power is infinite in acting. Therefore it was most becoming to the goodness of God, that He should give His creatures a beginning of their duration.

From what has been said we are able to avoid the various errors of the pagan philosophers. Some of whom asserted the eternity of the world; others asserted that the matter of the world is eternal, out of which at a certain time the world began to be formed; either by chance; or by some intellect; or else by attraction and repulsion. For all these suppose something eternal beside God: which is incompatible with the Catholic faith.