§9.3εἰσὶ δέ τινες οἵ φασιν, οἷον οἱ Μεγαρικοί, ὅταν ἐνεργῇ μόνον δύνασθαι, ὅταν δὲ μὴ ἐνεργῇ οὐ δύνασθαι, οἷον τὸν μὴ οἰκοδομοῦντα οὐ δύνασθαι οἰκοδομεῖν, ἀλλὰ τὸν οἰκοδομοῦντα ὅταν οἰκοδομῇ· ὁμοίως δὲ καὶ ἐπὶ τῶν ἄλλων.
There are some who say, for example the Megarians, that a thing is capable only when it is active, and when it is not active it is not capable; for example, that he who is not building cannot build, but only he who is building when he is building; and similarly in the other cases.
οἷς τὰ συμβαίνοντα ἄτοπα οὐ χαλεπὸν ἰδεῖν.
It is not difficult to see the absurd consequences that follow for them.
δῆλον γὰρ ὅτι οὔτʼ οἰκοδόμος ἔσται ἐὰν μὴ οἰκοδομῇ (τὸ γὰρ οἰκοδόμῳ εἶναι τὸ δυνατῷ εἶναί ἐστιν οἰκοδομεῖν), ὁμοίως δὲ καὶ ἐπὶ τῶν ἄλλων τεχνῶν.
For it is clear that a man will not even be a builder if he is not building (since to be a builder is to be capable of building), and similarly also in the case of the other arts.
εἰ οὖν ἀδύνατον τὰς τοιαύτας ἔχειν τέχνας μὴ μαθόντα ποτὲ καὶ λαβόντα, καὶ μὴ ἔχειν μὴ ἀποβαλόντα ποτέ (ἢ γὰρ λήθῃ ἢ πάθει τινὶ ἢ χρόνῳ· οὐ γὰρ δὴ τοῦ γε πράγματος φθαρέντος, ἀεὶ γὰρ ἔστιν), ὅταν παύσηται, οὐχ ἕξει τὴν τέχνην, πάλιν δʼ εὐθὺς οἰκοδομήσει πῶς λαβών;
If, then, it is impossible to possess such arts without having at some time learned and acquired them, and impossible not to possess them without having at some time lost them (either by forgetfulness or by some affection or by time; for it is certainly not because the object itself has been destroyed, for it always exists), when he ceases, he will not possess the art, and how then will he build again immediately, having acquired it?
καὶ τὰ ἄψυχα δὴ ὁμοίως· οὔτε γὰρ ψυχρὸν οὔτε θερμὸν οὔτε γλυκὺ οὔτε ὅλως αἰσθητὸν οὐθὲν ἔσται μὴ αἰσθανομένων· ὥστε τὸν Πρωταγόρου λόγον συμβήσεται λέγειν αὐτοῖς.
And similarly also with inanimate things; for neither cold nor hot nor sweet nor any sensible object at all will exist when there are none perceiving; so that it will turn out that they are saying the doctrine of Protagoras.
ἀλλὰ μὴν οὐδʼ αἴσθησιν ἕξει οὐδὲν ἂν μὴ αἰσθάνηται μηδʼ ἐνεργῇ.
But indeed, neither will anything have any senses if it is not perceiving and not active.
εἰ οὖν τυφλὸν τὸ μὴ ἔχον ὄψιν, πεφυκὸς δὲ καὶ ὅτε πέφυκε καὶ ἔτι ὄν, οἱ αὐτοὶ τυφλοὶ ἔσονται πολλάκις τῆς ἡμέρας, καὶ κωφοί.
If, then, that which does not have sight is blind, when it is natural for it to have it and when it is natural and while it still exists, the same people will be blind many times a day, and deaf as well.
ἔτι εἰ ἀδύνατον τὸ ἐστερημένον δυνάμεως, τὸ μὴ γιγνόμενον ἀδύνατον ἔσται γενέσθαι· τὸ δʼ ἀδύνατον γενέσθαι ὁ λέγων ἢ εἶναι ἢ ἔσεσθαι ψεύσεται (τὸ γὰρ ἀδύνατον τοῦτο ἐσήμαινεν), ὥστε οὗτοι οἱ λόγοι ἐξαιροῦσι καὶ κίνησιν καὶ γένεσιν.
Further, if that which is deprived of potentiality is impossible, that which is not happening will be impossible to happen; and he who says of that which is impossible to happen either that it is or that it will be will speak falsely (for this is what "impossible" meant); so that these arguments do away with both motion and generation.
ἀεὶ γὰρ τό τε ἑστηκὸς ἑστήξεται καὶ τὸ καθήμενον καθεδεῖται· οὐ γὰρ ἀναστήσεται ἂν καθέζηται· ἀδύνατον γὰρ ἔσται ἀναστῆναι ὅ γε μὴ δύναται ἀναστῆναι.
For that which is standing will always stand, and that which is sitting will sit; for it will not stand up if it is sitting, since it will be impossible for it to stand up if it is not capable of standing up.
εἰ οὖν μὴ ἐνδέχεται ταῦτα λέγειν, φανερὸν ὅτι δύναμις καὶ ἐνέργεια ἕτερόν ἐστιν (ἐκεῖνοι δʼ οἱ λόγοι δύναμιν καὶ ἐνέργειαν ταὐτὸ ποιοῦσιν, διὸ καὶ οὐ μικρόν τι ζητοῦσιν ἀναιρεῖν), ὥστε ἐνδέχεται δυνατὸν μέν τι εἶναι μὴ εἶναι δέ, καὶ δυνατὸν μὴ εἶναι εἶναι δέ, ὁμοίως δὲ καὶ ἐπὶ τῶν ἄλλων κατηγοριῶν δυνατὸν βαδίζειν ὂν μὴ βαδίζειν, καὶ μὴ βαδίζειν δυνατὸν ὂν βαδίζειν.
If, then, it is not possible to say these things, it is clear that potentiality and actuality are different (but those arguments make potentiality and actuality the same, and for this reason they seek to do away with no small thing); so that it is possible for a thing to be capable of being and yet not be, and capable of not being and yet be, and similarly in the case of the other categories, it is possible to be capable of walking and yet not walk, and not walking and yet be capable of walking.
ἔστι δὲ δυνατὸν τοῦτο ᾧ ἐὰν ὑπάρξῃ ἡ ἐνέργεια οὗ λέγεται ἔχειν τὴν δύναμιν, οὐθὲν ἔσται ἀδύνατον.
And that is capable which, if the actuality of that of which it is said to have the potentiality should belong to it, nothing will be impossible.
λέγω δὲ οἷον, εἰ δυνατὸν καθῆσθαι καὶ ἐνδέχεται καθῆσθαι, τούτῳ ἐὰν ὑπάρξῃ τὸ καθῆσθαι, οὐδὲν ἔσται ἀδύνατον· καὶ εἰ κινηθῆναι ἢ κινῆσαι ἢ στῆναι ἢ στῆσαι ἢ εἶναι ἢ γίγνεσθαι ἢ μὴ εἶναι ἢ μὴ γίγνεσθαι, ὁμοίως.
I mean, for example, if it is capable of sitting and is possible to sit, if sitting should belong to this, nothing will be impossible; and similarly if it is to be moved or to move, or to stand or to make stand, or to be or to become, or not to be or not to become.
ἐλήλυθε δʼ ἡ ἐνέργεια τοὔνομα, ἡ πρὸς τὴν ἐντελέχειαν συντιθεμένη, καὶ ἐπὶ τὰ ἄλλα ἐκ τῶν κινήσεων μάλιστα· δοκεῖ γὰρ ἡ ἐνέργεια μάλιστα ἡ κίνησις εἶναι, διὸ καὶ τοῖς μὴ οὖσιν οὐκ ἀποδιδόασι τὸ κινεῖσθαι, ἄλλας δέ τινας κατηγορίας, οἷον διανοητὰ καὶ ἐπιθυμητὰ εἶναι τὰ μὴ ὄντα, κινούμενα δὲ οὔ, τοῦτο δὲ ὅτι οὐκ ὄντα ἐνεργείᾳ ἔσονται ἐνεργείᾳ.
And the word "actuality" (energeia), which is put together in relation to "complete reality" (entelecheia), has extended to other things from motions especially; for actuality seems to be especially motion, and for this reason people do not assign "being moved" to non-existent things, though they do assign some other categories, for instance that non-existent things are thinkable and desirable, but not that they are moved; and this because, not being in actuality, they would be in actuality.
τῶν γὰρ μὴ ὄντων ἔνια δυνάμει ἐστίν· οὐκ ἔστι δέ, ὅτι οὐκ ἐντελεχείᾳ ἐστίν.
For of non-existent things, some exist potentially; but they are not, because they are not in complete reality.