§1#1## H (textus alter)
Απαν τὸ κινούμενον ἀνάγκη ὑπό τινος κινεῖσθαι.
## H (textus alter) Everything that is in motion must be moved by something.
εἰ μὲν οὖν ἐν αὐτῷ μὴ ἔχει τὴν ἀρχὴν τῆς κινήσεως, φανερὸν ὅτι ὑφʼ ἑτέρου κινεῖται (ἄλλο γὰρ ἔσται τὸ κινοῦν)·
If, on the one hand, it does not have the principle of motion in itself, it is obvious that it is moved by something else (for the mover will be other than it).
εἰ δʼ ἐν αὐτῷ, εἰλήφθω ἐφʼ οὗ τὸ ΑΒ, ὃ κινεῖται μὴ τῷ τῶν τούτου τι κινεῖσθαι.
But if, on the other hand, it has it in itself, let AB be taken as that which is in motion, not by the fact that some part of it is in motion.
πρῶτον μὲν οὖν τὸ ὑπολαμβάνειν τὸ ΑΒ ὑφʼ αὐτοῦ κινεῖσθαι διὰ τὸ ὅλον τε κινεῖσθαι καὶ ὑπὸ μηθενὸς τῶν ἔξωθεν ὅμοιόν ἐστιν ὥσπερ ἂν εἴ τις τοῦ ΔΕ κινοῦντος τὸ ΕΖ καὶ αὐτοῦ κινουμένου ὑπολαμβάνοι τὸ ΔΕΖ ὑφʼ αὐτοῦ κινεῖσθαι, διὰ τὸ μὴ συνορᾶν πότερον ὑπὸ ποτέρου κινεῖται, πότερον τὸ ΔΕ ὑπὸ τοῦ ΕΖ ἢ τὸ ΕΖ ὑπὸ τοῦ ΔΕ. ἔτι τὸ ὑφʼ αὐτοῦ κινούμενον οὐδέποτε παύσεται κινούμενον τῷ ἕτερόν τι στῆναι κινούμενον.
First, then, to suppose that AB is moved by itself because the whole is in motion and is moved by nothing external, is like as if, when DE moves EZ and is itself in motion, someone should suppose that DEZ is moved by itself, because of not seeing clearly which of them is moved by which, whether DE by EZ or EZ by DE. Furthermore, that which is moved by itself will never cease being in motion by the fact that something else in motion has come to a stop.
ἀνάγκη τοίνυν, εἴ τι παύεται κινούμενον τῷ ἕτερόν τι στῆναι, αὐτὸ ὑφ᾿ ἑτέρου κινεῖσθαι.
It is necessary, therefore, that if something ceases being in motion by the fact that something else has come to a stop, it is itself moved by something else.
τούτου δὲ φανεροῦ γενομένου ἀνάγκη πᾶν τὸ κινούμενον κινεῖσθαι ὑπό τινος.
This having become clear, everything that is in motion must be moved by something.
ἐπεὶ γὰρ εἴληπται τὸ ΑΒ κινούμενον, διαιρετὸν ἔσται· πᾶν γὰρ τὸ κινούμενον διαιρετὸν ἦν.
For since AB has been assumed to be in motion, it will be divisible; for everything that is in motion was divisible.
διῃρήσθω τοίνυν ᾗ τὸ Γ. ἀνάγκη δὴ τοῦ ΓΒ ἠρεμοῦντος ἠρεμεῖν καὶ τὸ ΑΒ. εἰ γὰρ μή, εἰλήφθω κινούμενον.
Let it, then, be divided at C. It is indeed necessary that if CB is at rest, AB also is at rest. For if not, let it be assumed to be in motion.
τοῦ τοίνυν ΓΒ ἠρεμοῦντος κινοῖτο ἂν τὸ ΓΑ. οὐκ ἄρα καθʼ αὐτὸ κινεῖται τὸ ΑΒ. ἀλλʼ ὑπέκειτο καθʼ αὑτὸ κινεῖσθαι πρῶτον.
Then while CB is at rest, CA would be in motion. Therefore AB is not moved in virtue of itself. But it was assumed at first to be moved in virtue of itself.
δῆλον τοίνυν ὅτι τοῦ ΓΒ ἠρεμοῦντος ἠρεμήσει καὶ τὸ ΒΑ, καὶ τότε παύσεται κινούμενον.
It is clear, then, that when CB is at rest, BA also will be at rest, and then it will cease being in motion.
ἀλλʼ εἴ τι τῷ ἄλλο ἠρεμεῖν ἵσταται καὶ παύεται κινούμενον, τοῦθʼ ὑφ᾿ ἑτέρου κινεῖται.
But if something stops and ceases being in motion by the fact that something else is at rest, this is moved by something else.
φανερὸν δὴ ὅτι πᾶν τὸ κινούμενου ὑπό τινος κινεῖται διαιρετόν τε γάρ ἐστιν πᾶν τὸ κινούμενον, καὶ τοῦ μέρους ἠρεμοῦντος ἠρεμήσει καὶ τὸ ὅλον.
It is clear, then, that everything that is in motion is moved by something; for everything that is in motion is divisible, and when the part is at rest, the whole also will be at rest.
ἐπεὶ
δὲ τὸ κινούμενον ὑπό τινος κινεῖται, ἀνάγκη καὶ τὸ κινούμενον πᾶν ἐν τόπῳ κινεῖσθαι ὑηʼ ἄλλου· καὶ τὸ κινοῦν τοίνυν ὑφʼ ἑτέρου, ἐπειδὴ καὶ αὐτὸ κινεῖται, καὶ πάλιν τοῦτο ὑφʼ ἑτέρου.
Since, however, that which is in motion is moved by something, everything that is in motion in place must also be moved by something else; and the mover, therefore, by something else, since it is itself also in motion, and this again by something else.
οὐ δὴ εἰς ἄπειρον πρόεισιν, ἀλλὰ στήσεταί που καὶ ἔσται τι ὃ πρώτως αἴτιον ἔσται τοῦ κινεῖσθαι.
It will not, indeed, proceed to infinity, but will stop somewhere, and there will be something which will be the primary cause of being moved.
εἰ γὰρ μή, ἀλλʼ εἰς ἄπειρον πρόεισιν, ἔστω τὸ μὲν Α ὑπὸ τοῦ Β κινούμενον, τὸ δὲ ὑπὸ τοῦ Γ, τὸ δὲ Γ ὑπὸ τοῦ Δ· καὶ τοῦτον δὴ τὸν τρόπον εἰς ἄπειρον προβαινέτω.
For if not, but it proceeds to infinity, let A be moved by B, and [B] by C, and C by D; and in this way let it proceed to infinity.
ἐπεὶ οὖν ἅμα τὸ κινοῦν καὶ αὐτὸ κινεῖται, δῆλον ὡς ἅμα κινήσεται τό τε Α καὶ τὸ Β· κινουμένου γὰρ τοῦ Β κινηθήσεται καὶ τὸ Α·
Since, then, the mover and that which is itself in motion are simultaneous, it is clear that both A and B will be in motion simultaneously; for when B is in motion, A also will be moved, and B when C is in motion, and C when D is in motion.
καὶ τὸ Β δὴ κινουμένου τοῦ Γ καὶ τὸ Γ τοῦ Δ. ἔσται τοίνυν ἅμα ἥ τε τοῦ Α κίνησις ⟨καὶ τοῦ Β⟩ καὶ τοῦ Γ καὶ τῶν λοιπῶν ἑκάστου.
There will be, therefore, simultaneously the motion of A, and of B, and of C, and of each of the rest.
καὶ λαβεῖν τοίνυν αὐτῶν ἑκάστην δυνησόμεθα.
We shall therefore be able to grasp each of them.
καὶ γὰρ εἰ ἕκαστον ὑφʼ ἑκάστου κινεῖται, οὐθὲν ἧττον μία τῷ ἀριθμῷ ἡ ἑκάστου κίνησις, καὶ οὐκ ἄπειρος τοῖς ἐσχάτοις, ἐπειδήπερ τὸ κινούμενον πᾶν ἔκ τινος εῖς τι κινεῖται.
For even if each is moved by each, the motion of each is none the less one in number, and not infinite at its extremes, since everything that is in motion is moved from something to something.