LECTURE 1 (250 b 11-251 a 7)

WHETHER OR NOT MOTION BEGAN OR WILL END

             965. After the Philosopher has shown in the preceding book that there must be a first mobile object and a first motion and a first mover, in this book he plans to inquire into the nature of the first mover and the first motion and the first mobile object.

             This discussion is divided into two parts. First, he sets forth something which is necessary for the following investigation, namely, the eternity of motion. Secondly, where he says, 'Our enquiry will resolve . . .' (253 a 22), he begins to investigate the problem.

             Concerning the first part he makes three points. First he raises the problem. Secondly, where he says, 'Let us take our start . . .' (251 a 8), he explains the truth according to his own opinion. Thirdly, where he says, 'The arguments that may . . .' (252 b 7), he answers objections to the contrary.

             Concerning the first part he makes three points. First he raises the problem. Secondly, where he says, 'But those who say . . .' (250 b 19), he gives opinions on both sides. Thirdly, where he says, 'We must consider, then . . .' (251 a 5), he points out the usefulness of this consideration.

             Concerning the first part he makes two points. First he raises a problem concerning that which he intends to investigate. Secondly, where he says, 'Now the existence of . . .' (250 b 15), he answers an unasked question.

             966. Concerning the first part it must be noted that Averroes says that in this chapter Aristotle does not intend to inquire universally whether motion is eternal but only whether the first motion is eternal.

             But if one considers both the words and the procedure of the Philosopher, he will see that this is totally false. For the Philosopher's words are spoken universally of motion, because he says, 'It remains to consider the following question. Was there ever a becoming of motion before which it had no being, and is it perishing again so as to leave nothing in motion?' (250 b 11-13). From this it is clearly apparent that he is not asking about any determinate motion. Rather he asks universally whether at some time there may have been nothing in motion.

             From Aristotle's procedure also this clearly is false.

             The first reason for this is that it is always his custom to argue to a proposition from proper things. And if one considers the following arguments which he introduces, in none of them does he use as a middle anything which pertains properly to the first motion, but rather to motion in general. From this it is clear enough that he intends to inquire here about the eternity of motion in general.

             A second reason is that if it were already proven that one or more motions are eternal, it would be useless for him to ask below whether some things are always moved, since this would already be proven. It is also ridiculous to say that Aristotle repeats his own thought below from the beginning, as if he had omitted something, as the Commentator suggests. For Aristotle had the opportunity of correcting his book and of supplying in the proper place what had been omitted, so that he would not proceed in a disorderly way. If this chapter is explained according to the intention of the Commentator, all that follows will appear to be confused and disordered. Nor is this strange, for from one inconsistent position others follow. The fact that Aristotle intends below to inquire into the eternity of the first motion is even more apparent from the fact that he uses that which he demonstrates here as a principle. This he could in no way do if he has proven here that the first motion is eternal.

             Moreover, the argument by which Averroes was moved is perfectly silly. He says that if it is said that Aristotle intends here to ask about the eternity of motion in general, it will follow that the consideration of Aristotle would be weakened here. For it is not apparent from what is determined here how motions can always be continuous to each other.

             But this is not so. In this chapter it is sufficient for Aristotle to prove in general that motion is eternal. In the immediate sequel he inquires how the eternity of motion is continued, whether because all things are always moved, or because all things are sometimes moved and sometimes at rest, or because certain things are always moved and other things are at times moved and at times at rest.

             Accordingly it should be understood that it is his intention in the present chapter to investigate motion in general.

             He asks, therefore, with respect to this whether motion at some time began to be, so that before this there was no motion at all, and whether at some time it will cease so that afterwards nothing is moved: or, on the contrary, whether it never began and never will cease, but always was and always will be.

             He gives an example dealing with animals, because some have said that the world is a certain large animal. We see that animals are alive so long as some motion is apparent in them. When every motion ceases, animals are said to be dead. Likewise in the whole universe the motions of natural bodies are thought of as a kind of life. If, then, motion always was and always will be, this life, as it were, of natural bodies will be immortal and without end.

             967. Next where he says, 'Now the existence of . . .' (250 b 15), he answers an unasked question.

             In the preceding books Aristotle has spoken about motion in general not applying his remarks to things. Now, however, inquiring whether motion always was, he applies the common consideration of motion to the existence which it has in things. Therefore, one might say that in this consideration one must ask whether motion has existence in things before one asks whether motion is eternal, especially since some have denied the existence of motion.

             He answers this by saying that all who have spoken of the nature of things affirm that motion exists. This is clear because they say that the world was made, and also because they all admit the generation and corruption of things, which could not occur without motion. It is, therefore, a common supposition in natural science that motion has existence in things. Therefore, no question is asked about this in natural science, just as in any science no question concerning the suppositions of that science is raised.

             968. Next where he says, 'But those who say . . .' (250 b 19), he gives opinions on both sides of the question which he has asked.

             First he gives the opinions of those who say that motion is eternal. Secondly, where he says, '. . . whereas those who hold . . .' (250 b 22), he gives the opinions of those who say that motion is not eternal.

             For a clear understanding of the first part, it should be known that Democritus proposed that the first principles of things are indivisible bodies which are mobile per se and eternally. He said that the world was made by chance from a coming together of these bodies. This applies not only to the world in which we exist but also to infinite other worlds insofar as the coming together of the above mentioned bodies has made worlds in diverse parts of an infinite void. He did not, however, propose that these worlds would endure forever. Rather some of them come to be through the aggregation of atoms, and some are corrupted by the separation of atoms. Therefore, all the philosophers who propose this along with Democritus say that motion is eternal, because they say that the generation and corruptions of some worlds are eternal. And this can occur only with motion.

             969. Next where he says, '. . . whereas those who hold . . .' (250 b 22), he gives contrary opinions.

             He says that all who hold that there is only one world which is not eternal, hold in regard to motion what follows according to reason, namely, it is not eternal.

             If, therefore, it is granted that there was a time in which nothing was moved, this may occur in two ways, just as it can be maintained in two ways that this world has not always existed. The first view is that this world so began that it never was before, as Anaxagoras held. The second view is that the world so began that at some time it was not, but before that time it existed, as Empedocles held.

             And accordingly Anaxagoras said of motion that at one time all things were together, one mingled with another, and nothing was separated from any other thing. In this mixture of things it was necessary to hold that everything was at rest. For there is no motion without separation, since everything which is moved withdraws from one thing in order to tend toward another. He held, therefore, that this mixture and state of rest of things pre-existed in an infinite time, so that at no earlier time was there any motion. And intellect, which was the only thing not intermixed, began anew to cause motion and to separate things from one another.

             But Empedocles said that in one part of time something was moved, and again in another part of time all things were at rest. For Empedocles held that friendship and strife are the first movers of things. The proper function of friendship is to make one from many, while strife makes many from one. Since the existence of a mixed body requires that its elements be joined into one, and since the existence of the world requires that the elements be distributed in their proper places in an orderly way, he held that friendship is the cause of the generation of mixed bodies, and strife is the cause of their corruption. But, on the contrary, in the whole world friendship is the cause of corruption and strife is the cause of generation.

             Thus he held that the whole world is moved either when friendship makes one from many, or when strife makes many from one. And he held that rest exists in the intermediate times, not indeed so that nothing is moved, but in respect to the general mutation of the world.

             Since Aristotle has stated the opinion of Empedocles, he also gives his words, which are difficult because he wrote in verse.

             Empedocles expressed his opinion in these words, which are to be understood as follows. 'Didicit nasci,' that is, a thing is usually generated, 'inquantum ex pluribus fit unum' [insofar as one comes to be from many], 'iterum', that is, in another way, 'ex uno geminato', that is, from the composite, 'perficiuntur plurima', that is, many come to be by separation. For some things are generated by composition and some things are generated by separation.

             And as we see this in particular generations, 'sic fiunt res', that is, the universal generation of things in respect to the whole world must be understood in the same way. 'Et nullo modo est ipsius saeculum unum,' that is, there is not one state of duration of things. Rather at one time the world is being generated, at another time it is being corrupted, and at another time it is in an intermediate state. For 'saeculum' means the measure of the duration of a thing.

             Moreover, he expresses the distinction of these durations when he adds, 'sic autem permutantur'. It is as if he were to say that one duration is that in which a thing is changed by congregation or separation. One might think that the world comes to be in an instant and that the generation of the world does not require a duration, that is, some time. To reject this he adds, 'neque simul perficiuntur' [they are not completed at once], but through a long delay of time.

             Next in regard to the other duration he says, 'sic autem semper sunt immobiles', that is, in the time which is intermediate between generation and corruption things are at rest.

             And one might believe that before this there was always change, and afterwards there always will be rest. To reject this he says, 'secundum circulum', as if he were to say that there is a circle in which things are changed and then are at rest and then are changed and so forth to infinity.

             Next are added the words of Aristotle who explains the words of Empedocles, especially the phrase, 'sic autem permutantur'.

             He says that the words 'sic permutantur' must be understood to mean 'from here to there', that is, from some beginning up to now. This does not mean that there always was motion, or that afterwards it began. Rather it means that motion is interrupted.

             970. Next where he says, 'We must consider, then . . .' (251 a 5), he points out the usefulness of this consideration.

             He says that consideration must be given to what the truth is concerning this question. For to know the truth about this question is elementary, that is, very necessary, not only for the consideration of natural science but also for the science of the first principle. For both here in Book VIII and in the Metaphysics he uses the eternity of motion to prove a first principle.

             This way of proving that a first principle exists is most effective and cannot be resisted. For if it is necessary to posit one first principle on the assumption that the world and motion are eternal, this is much more necessary if the eternity of these things is denied. For it is clear that every new thing needs some innovating principle. Therefore, only if things exist from eternity can it seem to be unnecessary to posit a first principle. And if it follows even from this assumption that a first principle exists, it is shown that it is absolutely necessary for a first principle to exist.