Commentary Aristotle Physics
And again, because we are supposing that all mobiles and motions are ceasing to be, it will be necessary later that even the cause of their ceasing to be ceases to be. But because ceasing to be is a type of motion, it will follow that, after the final change, other changes occur. But, since this is impossible, it follows that motion endures forever.
986. These, therefore, are the arguments by which Aristotle intends to prove that motion always has been and will never cease. The first part of this—namely, that motion always existed—conflicts with our faith. For our faith admits nothing as eternally existing but God alone, who is utterly immobile—unless, of course, you wish to refer to the act of the divine intellect as a motion. But that would be an equivocal sense, and Aristotle is not here speaking of motion in that sense, but of motion properly so called.
The other part of the conclusion is not entirely contrary to the faith, because, as was said above, Aristotle is not treating of the motion of the heavens in particular but of motion universally. Now, we believe according to our faith that the substance of the world indeed began, yet so as never to cease. For we posit that some motions will always exist, especially in men, who will always remain living an unceasing life either of happiness or misery.
But some, vainly trying to show that Aristotle concluded nothing contrary to the faith, have said that Aristotle does not intend here to prove as a truth that motion is eternal, but to allege reason for both sides of a question that is doubtful. But this is a foolish statement to anyone who investigates Aristotle’s procedure here. Moreover, he uses the eternity of time and of motion as a principle to prove the existence of a first principle both here in Physics 8 and in Metaphysics 12. This shows that he considered it proved.
987. But, if one rightly considers the arguments here given, the truth of the faith is not assailed by them. For they prove that motion did not begin through the way of nature, as some taught it did; but it cannot be proved by these arguments that it did not begin by things being created by a first principle of things, as our faith holds. And that will be evident to anyone who considers each of the inferences here drawn by Aristotle.
For when he asks whether or not the movers and mobiles always existed if motion did not always exist, the reply must be that the first mover always existed; other things—movers or mobiles—did not always exist, but began to exist from the universal cause of all existence. But it has been pointed out above that the production of all being by the first cause of being is not a motion, whether this coming forth be taken to be from eternity or not. Accordingly, it does not follow that, before the first change, there was a previous change. But this would follow if the movers and mobiles were newly brought into existence by some particular agent acting upon some presupposed subject that would be changed from non-being to being, or from privation to form—and Aristotle’s argument concerns this way of coming into existence.
988. But, because we posit that at least a first mover always existed, we need to give an answer to his subsequent deduction that, if movers and mobiles preexist and motion begins newly to be in them, then the movers or mobiles could not previously have been in that disposition in which they are while there is motion; therefore, some change must have preceded the first change.
Now, if we are speaking of the motion itself, the answer is easy. The mobiles were not previously in that disposition in which they now are, because previously they did not exist; hence, they could not be moved. But, as it has been said, they received their existence not through a change or motion, but through coming forth from the first principle of things; accordingly, it does not follow that, before the first change, there was a change. But there still remains the question about the first production of things. For if the first principle, which is God, is no different now than before, then neither does he produce things now any more than before; but if he is different, at least the change affecting him will be prior to the change that is supposed to be the first.
And indeed, if he were a cause that acts only through nature and not through intellect and will, this reason would conclude necessarily. But, because he acts through will, he can produce an effect that is non-eternal through an eternal will, just as, by his eternal intellect, he can understand a thing that is non-eternal—the thing understood being in a certain way the principle of action in causes that act by intellect, as a natural form is in causes that act by nature.
989. But a further point must be pursued. For we do not say that a will postpones doing what it wants unless something is expected in the future that does not yet exist in the present, as, for example, when I will to make a fire later rather than now because it is expected to be cold in the future (or at least this is expected at the present time), on account of which I make the fire. But that time succeeds time does not occur without motion. Therefore, it cannot be that a will, even if it be immutable, postpones doing what it wills without some motion being involved. Accordingly, the new production of things cannot come forth from the eternal will except by means of motions succeeding one another to infinity.
Now, those who raise this objection fail to see that it assumes a thing acting in time, namely, something that acts on the assumption that time exists. For in this kind of action that occurs in time, one must consider some determinate relationship to this time or to things that exist in this time to explain why it be performed in this time rather than in some other time. But this reasoning has no place in the universal agent, which produces time itself at the same time that it produces other things.
For when we say that things have not always been produced by God, we do not understand that an infinite time preceded in which God refrained from acting, and that later, at a definite time, he began to act; rather, we understand that God produced at once both time and things after they did not exist. Accordingly, we must not consider in the divine will that it willed to make things not then but later, as though time were already existing; rather, we must solely consider the fact that he willed that things and the time of their duration should begin to be after they had not existed at all.
If it be asked why he willed this, it must be said without a doubt that it was for his own sake. For just as he made things because of himself, in order that, in them, the likeness of his goodness be manifested, so he willed that they not always be, in order to show his self-sufficiency through that, even though nothing else existed, he in himself had all sufficiency of happiness and of power to produce things.
And this can indeed be said as far as human reason can grasp divine things, saving, of course, the secret of divine wisdom, which cannot be comprehended by us.
990. Because the solution of this argument proceeded on the supposition that time did not always exist, there remains the problem of solving the argument that seems to prove that time always existed. And perhaps Aristotle, after the argument from motion, gave one from time, because he thought that the one from motion would be inefficacious unless time was assumed to be eternal. Thus, his statement that, whenever there is time, there must be a now existing, must be granted without demur. But the statement that every now is both a beginning and an end should not be conceded unless it be also granted that motion always existed, such that every indivisible of motion (which is called a “moment”) should be both a beginning and an end of motion, for the now is to the moment as time is to motion. If, therefore, we suppose that motion has not always existed, but that we can take some first indivisible in motion before which nothing of motion existed, we can also take some now in time before which there was no time.
Now, we have already shown, in explaining the text, that what Averroes says to bolster this argument is inefficacious. But neither is there any efficacy in what Aristotle cites to bolster his own position, namely, that before and after do not exist without time.
For when we say that a time’s beginning is that before which nothing of the time existed, we are not thereby compelled to say that the now that is the beginning of the time is preceded by a time signified by the word “before,” any more than, in magnitudes, if I say that the beginning of a magnitude is that beyond which nothing exists of that magnitude, it is necessary to say that the phrase “beyond which beginning” signifies some real place existing in nature, for it signifies an imaginary one only.
Otherwise, it would be necessary to posit a place beyond the universe, whose magnitude is finite and has a beginning and an end.
Similarly, the first now that is the beginning of time is not preceded by a time existing in reality, but only in our imagination. And this is the time that is described when one says that the first now is the beginning of time, before which nothing of time exists.
Or it may be said that, in the expression “the beginning of time is that before which nothing of time exists,” the word “before” is not affirmed, but denied—and so it is not necessary to posit a time before the beginning of time. For in things that exist in time, it happens that some certain time precedes their beginning, as, when it is said that the beginning of youth is that before which there was nothing of youth, the word “before” can be taken in an affirmative sense, because youth is measured by time. But time is not measured by time, and thus no time preceded its beginning; hence the word “before” in the definition of time is not taken affirmatively but negatively.
But, before time, there does exist a duration, namely, the eternity of God. But this eternity has no extension or any before or after as time does; rather, it is all at once and is not of the same account as time any more than the divine magnitude is of the same account as a bodily magnitude.
Therefore, just as we are not positing some dimension outside the world when we say that, outside the universe, there is nothing but God, so too, when we say that, before the universe, nothing existed, we are not positing any sort of successive duration before the universe.