§8.9Ὅτι δὲ τῶν φορῶν ἡ κυκλοφορία πρώτη, δῆλον.
That circular motion is the first of locomotions is clear.
πᾶσα γὰρ φορά, ὥσπερ καὶ πρότερον εἴπομεν, ἢ κύκλῳ ἢ ἐπʼ εὐθείας ἢ μικτή.
For every locomotion, as we said before, is either in a circle, or in a straight line, or mixed.
ταύτης δὲ ἀνάγκη προτέρας εἶναι ἐκείνας· ἐξ ἐκείνων γὰρ συνέστηκεν.
And those must be prior to this; for it is composed of them.
τῆς δʼ εὐθείας ἡ κύκλῳ· ἁπλῆ γὰρ καὶ τέλειος μᾶλλον.
And the circular is prior to the straight; for it is simpler and more complete.
ἄπειρον μὲν γὰρ οὐκ ἔστιν εὐθεῖαν φέρεσθαι (τὸ γὰρ οὕτως ἄπειρον οὐκ ἔστιν· ἅμα δʼ οὐδʼ εἰ ἦν, ἐκινεῖτʼ ἂν οὐδέν· οὐ γὰρ γίγνεται τὸ ἀδύνατον, διελθεῖν δὲ τὴν ἄπειρον ἀδύνατον)· ἡ δʼ ἐπὶ τῆς πεπερασμένης ἀνακάμπτουσα μὲν συνθετὴ καὶ δύο κινήσεις, μὴ ἀνακάμπτουσα δὲ ἀτελὴς καὶ φθαρτή.
For it is not possible to be carried along an infinite straight line (for there is no such infinite; and at the same time, even if it were, nothing would move; for the impossible does not happen, and to traverse the infinite is impossible); and that on a finite straight line is, if it turns back, composite and two motions, and if it does not turn back, incomplete and perishable.
πρότερον δὲ καὶ φύσει καὶ λόγῳ καὶ χρόνῳ τὸ τέλειον μὲν τοῦ ἀτελοῦς, τοῦ φθαρτοῦ δὲ τὸ ἄφθαρτον.
But the complete is prior to the incomplete, and the imperishable to the perishable, both by nature and by definition and in time.
ἔτι προτέρα ἣν ἐνδέχεται ἀΐδιον εἶναι τῆς μὴ ἐνδεχομένης· τὴν μὲν οὖν κύκλῳ ἐνδέχεται ἀΐδιον εἶναι, τῶν δὲ ἄλλων οὔτε φορὰν οὔτε ἄλλην οὐδεμίαν· στάσιν γὰρ δεῖ γενέσθαι, εἰ δὲ στάσις, ἔφθαρται ἡ κίνησις. εὐλόγως δὲ συμβέβηκε
τὸ τὴν κύκλῳ μίαν εἶναι καὶ συνεχῆ, καὶ μὴ τὴν ἐπʼ εὐθείας' τῆς μὲν γὰρ ἐπʼ εὐθείας ὥρισται καὶ ἀρχὴ καὶ τέλος καὶ μέσον, καὶ πάντʼ ἔχει ἐν αὐτῇ, ὥστʼ ἔστιν ὅθεν ἄρξεται τὸ κινούμενον καὶ οὗ τελευτήσει (πρὸς γὰρ τοῖς πέρασιν ἠρεμεῖ πᾶν, ἢ ὅθεν ἢ οὗ), τῆς δὲ περιφεροῦς ἀόριστα·
Furthermore, that which can be eternal is prior to that which cannot; now the circular can be eternal, but of the others, neither locomotion nor any other [motion] can be; for there must be a stopping, and if there is a stopping, the motion has perished.\n\nIt has happened reasonably that the circular motion is one and continuous, and not the one along a straight line; for in the straight motion, the beginning, the end, and the middle are determined, and it has all of them in itself, so that there is a place from which the thing in motion will begin and where it will end (for everything rests at the extremities, either where it starts or where it ends), whereas in the circular motion, they are undetermined; for why should any point whatever on the line be a limit rather than another?
τί γὰρ μᾶλλον ὁποιονοῦν πέρας τῶν ἐπὶ τῆς γραμμῆς; ὁμοίως γὰρ ἕκαστον καὶ ἀρχὴ καὶ μέσον καὶ τέλος, ὥστʼ ἀεί τε εἶναι ἐν ἀρχῇ καὶ ἐν τέλει καὶ μηδέποτε.
For each is similarly a beginning, a middle, and an end, so that it is always in a beginning and in an end, and never.
διὸ κινεῖταί τε καὶ ἠρεμεῖ πως ἡ σφαῖρα· τὸν αὐτὸν γὰρ κατέχει τόπον.
Therefore, the sphere in a way both moves and rests; for it occupies the same place.
αἴτιον δʼ ὅτι πάντα συμβέβηκε ταῦτα τῷ κέντρῳ· καὶ γὰρ ἀρχὴ καὶ μέσον τοῦ μεγέθους καὶ τέλος ἐστίν, ὥστε διὰ τὸ ἔξω εἶναι τοῦτο τῆς περιφερείας οὐκ ἔστιν ὅπου τὸ φερόμενον ἠρεμήσει ὡς διεληλυθός (ἀεὶ γὰρ φέρεται περὶ τὸ μέσον, ἀλλʼ οὐ πρὸς τὸ ἔσχατον), διὰ δὲ τὸ τοῦτο μένειν ἀεί τε ἠρεμεῖ πως τὸ ὅλον καὶ κινεῖται συνεχῶς.
And the cause is that all these things belong to the center; for it is the beginning, the middle, and the end of the magnitude, so that, because this is outside the circumference, there is no place where the thing carried will rest as having completed its passage (for it is always carried around the middle, but not toward the extremity), and because this remains, the whole also both in a way always rests and moves continuously.
συμβαίνει δʼ ἀντιστρόφως· καὶ γὰρ ὅτι μέτρον τῶν κινήσεων ἡ περιφορά, πρώτην ἀναγκαῖον αὐτὴν εἶναι (ἅπαντα γὰρ μετρεῖται τῷ πρώτῳ, καὶ διότι πρώτη, μέτρον ἐστὶν τῶν ἄλλων.
And it happens conversely: for both because the circular motion is the measure of motions, it must be the first (for all things are measured by the first), and because it is the first, it is the measure of the others.
ἔτι δὲ καὶ ὁμαλῆ ἐνδέχεται εἶναι τὴν κύκλῳ μόνην· τὰ γὰρ ἐπʼ εὐθείας ἀνωμαλῶς ἀπὸ τῆς ἀρχῆς φέρεται καὶ πρὸς τὸ τέλος· πάντα γὰρ ὅσῳπερ ἂν ἀφίστηται τοῦ ἠρεμοῦντος, φέρεται θᾶττον· τῆς δὲ κύκλῳ μόνης οὔτʼ ἀρχὴ οὔτε τέλος ἐν αὐτῇ πέφυκεν, ἀλλʼ ἐκτός.
Furthermore, the circular motion alone can be uniform; for things on a straight line are carried non-uniformly from the beginning and toward the end; for everything, the further it stands away from that which is at rest, is carried faster; but of the circular motion alone, neither the beginning nor the end is naturally in it, but outside.\n\nThat locomotion in respect of place is the first of motions, all those who have made mention of motion bear witness; for they attribute its principles to those things which cause such motion.
ὅτι δʼ ἡ κατὰ τόπον φορὰ πρώτη τῶν κινήσεων, μαρτυροῦσι πάντες ὅσοι περὶ κινήσεως πεποίηνται μνείαν· τὰς γὰρ ἀρχὰς αὐτῆς ἀποδιδόασιν τοῖς κινοῦσι τοιαύτην κίνησιν. διάκρισις γὰρ καὶ σύγκρισις κινήσεις κατὰ τόπον εἰσίν, οὕτω δὲ κινοῦσιν ἡ φιλία καὶ τὸ νεῖκος· τὸ μὲν γὰρ διακρίνει, τὸ δὲ συγκρίνει αὐτῶν.
For separation and association are motions in respect of place, and in this way Love and Strife cause motion; for one of them separates, and the other associates.
καὶ τὸν νοῦν δέ φησιν Ἀναξαγόρας διακρίνειν τὸν κινήσαντα πρῶτον.
And Anaxagoras also says that Mind, which first set things in motion, separates.
ὁμοίως δὲ καὶ ὅσοι τοιαύτην μὲν οὐδεμίαν αἰτίαν λέγουσιν, διὰ δὲ τὸ κενὸν κινεῖσθαί φασιν· καὶ γὰρ οὗτοι τὴν κατὰ τόπον κίνησιν κινεῖσθαι τὴν φύσιν λέγουσιν (ἡ γὰρ διὰ τὸ κενὸν κίνησις φορά ἐστιν καὶ ὡς ἐν τόπῳ), τῶν δʼ ἄλλων οὐδεμίαν ὑπάρχειν τοῖς πρώτοις ἀλλὰ τοῖς ἐκ τούτων οἴονται· αὐξάνεσθαι γὰρ καὶ φθίνειν καὶ ἀλλοιοῦσθαι συγκρινομένων καὶ διακρινομένων τῶν ἀτόμων σωμάτων φασίν.
And likewise also those who mention no such cause, but say that things move because of the void; for these too say that nature moves with the motion in respect of place (for motion through the void is locomotion and as if in place), and they think that none of the other motions belongs to the primary things, but only to those composed of them; for they say that things increase and decrease and are altered by the association and separation of indivisible bodies (atoms).
τὸν αὐτὸν δὲ τρόπον καὶ ὅσοι διὰ πυκνότητα ἢ μανότητα κατασκευάζουσι γένεσιν καὶ φθοράν· συγκρίσει γὰρ καὶ διακρίσει ταῦτα διακοσμοῦσιν.
And in the same way also those who account for generation and destruction by density and rarity; for they order these things by association and separation.
ἔτι δὲ παρὰ τούτους οἱ τὴν ψυχὴν αἰτίαν ποιοῦντες κινήσεως· τὸ γὰρ αὐτὸ αὐτὸ κινοῦν ἀρχὴν εἶναί φασιν τῶν κινουμένων, κινεῖ δὲ τὸ ζῶον καὶ πᾶν τὸ ἔμψυχον τὴν κατὰ τόπον αὐτὸ κίνησιν.
And furthermore, besides these, those who make the soul the cause of motion; for they say that that which moves itself is the principle of things in motion, and the animal and everything animate moves itself with the motion in respect of place.
καὶ κυρίως δὲ κινεῖσθαί φαμεν μόνον τὸ κινούμενον κατὰ τόπον· ἂν δʼ ἠρεμῇ μὲν ἐν τῷ αὐτῷ, αὐξάνηται δʼ ἢ φθίνῃ ἢ ἀλλοιούμενον τυγχάνῃ. πῂ κινεῖσθαι, ἁπλῶς δὲ κινεῖσθαι οὔ φαμεν. ὅτι μὲν οὖν ἀεί τε κίνησις ἦν καὶ ἔσται τὸν ἅπαντα χρόνον, καὶ τίς ἀρχὴ τῆς ἀϊδίου κινήσεως, ἔτι δὲ τίς πρώτη κίνησις, καὶ τίνα κίνησιν ἀΐδιον ἐνδέχεται μόνην εἶναι, καὶ τὸ κινοῦν πρῶτον ὅτι ἀκίνητον, εἴρηται.
And in the strict sense, we say that only that is in motion which moves in respect of place; but if it rests in the same place and increases or decreases or happens to be altered, we say that it moves in a certain way, but we do not say that it moves absolutely.\n\nThat, therefore, motion always was and will be for all time, and what is the principle of the eternal motion, and furthermore what is the first motion, and what motion alone can be eternal, and that the first mover is unmoved, has been said.