§3.2Ὅτι δὲ καλῶς εἴρηται, δῆλον καὶ ἐξ ὧν οἱ ἄλλοι περὶ αὐτῆς λέγουσιν, καὶ ἐκ τοῦ μὴ ῥάδιον εἶναι διορίσαι ἄλλως αὐτήν.
That our account has been well stated is clear both from what others say about motion, and from the fact that it is not easy to define it otherwise.
οὔτε γὰρ τὴν κίνησιν καὶ τὴν μεταβολὴν ἐν ἄλλῳ γένει θεῖναι δύναιτʼ ἄν τις, δῆλόν τε σκοποῦσιν ὡς τιθέασιν αὐτὴν ἔνιοι, ἑτερότητα καὶ ἀνισότητα καὶ τὸ μὴ ὄν φάσκοντες εἶναι τὴν κίνησιν· ὦν οὐδὲν ἀναγκαῖον κινεῖσθαι, οὔτʼ ἂν ἕτερα ᾖ οὔτʼ ἂν ἄνισα οὔτʼ ἂν οὐκ ὄντα·
For one could not place motion and change in any other genus, and it is clear to those who consider how some place it, by asserting that motion is "otherness", "inequality", and "non-being"; none of these, however, is necessarily moved, whether they are other, or unequal, or non-being.
ἀλλʼ οὐδʼ ἡ μεταβολὴ οὔτʼ εἰς ταῦτα οὔτʼ ἐκ τούτων μᾶλλόν ἐστιν ἢ ἐκ τῶν ἀντικειμένων.
Furthermore, change is no more into these or out of these than out of their opposites.
σἴτιον δὲ τοῦ εἰς ταῦτα τιθέναι ὅτι ἀόριστόν τι δοκεῖ εἶναι ἡ κίνησις, τῆς δὲ ἑτέρας συστοιχίας αἱ ἀρχαὶ διὰ τὸ στερητικαὶ εἶναι ἀόριστοι· οὔτε γὰρ τόδε οὔτε τοιόνδε οὐδεμία αὐτῶν ἐστιν, οὐδὲ τῶν ἄλλων κατηγοριῶν.
The reason for their placing it among these is that motion seems to be something indefinite, and the principles of the other co-ordinate series, being privative, are indefinite; for none of them is a "this" or "of such a quality", nor of any of the other categories.
τοῦ δὲ δοκεῖν ἀόριστον εἶναι τὴν κίνησιν σἴτιον ὅτι οὔτε εἰς δύναμιν τῶν ὄντων οὔτε εἰς ἐνέργειαν ἔστιν θεῖναι αὐτήν· οὔτε γὰρ τὸ δυνατὸν ποσὸν εἶναι κινεῖται ἐξ ἀνάγκης οὔτε τὸ ἐνεργείᾳ ποσόν, ῆ τε κίνησις ἐνέργεια μὲν εἶναί τις δοκεῖ, ἀτελὴς δέ· αἴτιον δʼ ὅτι ἀτελὲς τὸ δυνατόν, οὗ ἐστιν ἐνέργεια.
And the reason why motion seems to be indefinite is that it cannot be placed either under the potentiality or under the activity of existing things; for neither that which is potentially of a certain quantity is necessarily moved, nor that which is of a certain quantity in activity. And motion seems to be a certain activity, but incomplete; the reason is that the potential, of which it is the activity, is incomplete.
καὶ διὰ τοῦτο δὴ χαλεπὸν αὐτὴν λαβεῖν τί ἐστιν· ἢ γὰρ εἰς στέρησιν ἀναγκαῖον θεῖναι ἢ εἰς δύναμιν ἢ εἰς ἐνέργειαν ἀπλῆν, τούτων δʼ οὐδὲν φαίνεται ἐνδεχόμενον.
And for this very reason indeed, it is difficult to grasp what it is; for it is necessary to place it either in privation, or in potentiality, or in simple activity, but none of these appears to be possible.
λείπεται τοίνυν ὁ εἰρημένος τρόπος, ἐνέργειαν μέν τινα εἶναι, τοιαύτην δʼ ἐνέργειαν οἵαν εἴπαμεν, χαλεπὴν μὲν ἰδεῖν, ἐνδεχομένην δʼ εἶναι.
There remains then the aforementioned way, namely, that it is a certain activity, but such an activity as we have said, difficult to see, but capable of being.
κινεῖται δὲ καὶ τὸ κινοῦν ὥσπερ εἴρηται πᾶν, τὸ
δυνάμει ὄν κινητόν, καὶ οὖ ἡ ἀκινησία ἠρεμία ἐστίν (ᾦ γὰρ ἡ κίνησις ὑπάρχει, τούτου ἡ ἀκινησία ἠρεμία).
And everything that moves also moves, as has been said, namely, that which is potentially movable, and of which the immobility is rest (for the immobility of that to which motion belongs is rest).
τὸ γὰρ πρὸς τοῦτο ἐνεργεῖν, ᾖ τοιοῦτον, αὐτὸ τὸ κινεῖν ἐστι· τοῦτο δὲ ποιεῖ θίξει, ὥστε ἅμα καὶ πάσχει·
For to be active towards this, in so far as it is such, is precisely to move; and it does this by contact, so that it is at the same time acted upon.
διὸ ἡ κίνησις ἐντελέχεια τοῦ κινητοῦ, ᾖ κινητόν, συμβαίνει δὲ τοῦτο θίξει τοῦ κινητικοῦ, ὥσθ’ ἅμα καὶ πάσχει.
Therefore, motion is the fulfillment of the movable, as movable, and this happens by contact with the mover, so that the mover is at the same time acted upon.
εἶδος δὲ ἀεὶ οἴσεταί τι τὸ κινοῦν, ἤτοι τόδε ἢ τοιόνδε ἢ τοσόνδε, ὅ ἔσται ἀρχὴ καὶ αἴτιον τῆς κινήσεως, ὅταν κινῇ, οἶον ὁ ἐντελεχείᾳ ἄνθρωπος ποιεῖ ἐκ τοῦ δυνάμει ὄντος ἀνθρώπου ἄνθρωπον.
And the mover will always bring some form, either a "this" or "of such a quality" or "of such a quantity", which will be the principle and cause of the motion when it moves, just as the man in fulfillment makes a man out of that which is potentially a man.