§2.2.11Ἐπεὶ δὲ ἐπίστασθαι οἰόμεθα ὅταν εἰδῶμεν τὴν αἰτίαν, αἰτίαι δὲ τέτταρες, μία μὲν τὸ τί ἦν εἶναι, μία δὲ τὸ τίνων ὄντων ἀνάγκη τοῦτʼ εἶναι, ἑτέρα δὲ ἡ τί πρῶτον ἐκίνησε, τετάρτη δὲ τὸ τίνος ἕνεκα, πᾶσαι αὗταί διὰ τοῦ μέσου δείκνυνται.
Since we think we have knowledge when we know the cause, and causes are four: one, the essence; another, that which being the case, it is necessary for this to be; a third, that which first initiated motion; and a fourth, that for the sake of which; all these are shown through the middle term.
τό τε γὰρ οὗ ὄντος τοδὶ ἀνάγκη εἶναι μιᾶς μὲν τπροτάσεως ληφθείσης οὐκ ἔστι, δυοῖν δὲ τοῦτο δʼ ἐστίν, ὅταν ἕν μέσον ἔχωσιν.
For that which being the case, it is necessary for this to be does not occur when only one premise is taken, but when two premises are taken, and this is when they have one middle term.
τούτου οὖν ἑνὸς ληφθέντος τὸ συμπέρασμα ἀνάγκη εἶναι.
When this one is taken, therefore, the conclusion is necessary.
δῆλον δὲ καὶ ὧδε.
This is also clear as follows.
διὰ τί ὀρθὴ ἡ ἐν ἡμικυκλίῳ;
Why is the angle in a semicircle a right angle?
τίνος ὄντος ὀρθή;
What being the case, is it a right angle?
ἔστω δὴ ὀρθὴ ἐφʼ ἦς Α, ἡμίσεια δυοῖν ὀρθαῖν ἐφʼ ἦς Β, ἡ ἐν ἡμικυκλίῳ ἐφʼ ἧς Γ. τοῦ δὴ τὸ τὴν ὀρθὴν ὑπάρχειν τῷ Γ τῇ ἐν τῷ ἡμικυκλίῳ αἴτιον τὸ Β. αὕτη μὲν γὰρ τῇ Α ἴση, ἡ δὲ τὸ Γ τῇ Β· δύο γὰρ ὀρθῶν ἡμίσεια.
Let right angle be A, half of two right angles be B, and the angle in a semicircle be Γ. Of the right angle belonging to Γ, the angle in the semicircle, the cause is B. For B is equal to A, and Γ to B (since it is half of two right angles).
τοῦ Β οὖν ὄντος ἡμίσεος δύο ὀρθῶν τὸ τῷ Γ ὑπάρχει (τοῦτο δʼ ἦν τὸ ἐν ἡμικυκλίῳ ὀρθὴν εἶναι).
Therefore, when B, the half of two right angles, is the case, A belongs to Γ (and this was for the angle in a semicircle to be a right angle).
τοῦτο δὲ ταὐτόν ἐστι τῷ τί ἦν εἶναι, τῷ τοῦτο σημαίνειν τὸν λόγον.
And this is the same as the essence, since the account signifies this.
ἀλλὰ μὴν καὶ τὸ τί ἦν εἶναι αἴτιον δέδεικται τὸ μέσον 〈τὅν〉.
But indeed, the essence has been shown to be the middle term as the cause.
Τὸ δὲ διὰ τί ὁ Μηδικὸς πόλεμος ἐγένετο Ἀθηναίοις;
And why did the Persian War happen to the Athenians?
τίς αἰτία τοῦ πολεμεῖσθαι Ἀθηναίους;
What was the cause of the Athenians being warred upon?
ὅτι εἰς Σάρδεις μετʼ Ἐρετριέων ἐνέβαλον· τοῦτο γὰρ ἐκίνησε πρῶτον.
Because they invaded Sardis with the Eretrians; for this initiated motion first.
τπόλεμος ἐφʼ οὗ Α, προτέρους εἰσβαλεῖν Β, Ἀθηναῖοι τὸ Γ. ὑπάρχει δὴ τὸ Β τῷ Γ, τὸ προτέροις ἐμβαλεῖν τοῖς θηναίοις, τὸ δὲ τῷ Β· πολεμοῦσι γὰρ τοῖς πρότερον ἀδικήσασιν.
War is A, initiating the invasion is B, and the Athenians are Γ. Now B belongs to Γ, initiating the invasion belongs to the Athenians, and A belongs to B; for people make war on those who first did wrong.
ὑτπάρχει ἄρα τῷ μὲν Β τὸ Α, τὸ πολεμεῖσθαι τοῖς προτέροις ἄρξασι· τοῦτο δὲ ὸ Β τοῖς Θηναίοις· πρότεροι γὰρ ἦρξαν.
Therefore, A belongs to B, being warred upon belongs to those who first began, and this B belongs to the Athenians; for they began first.
μέσον ἄρα καὶ ἐνταῦθα τὸ σἴτιον, τὸ τπρῶτον κινῆσαν.
Here too, then, the cause, that which first initiated motion, is the middle term.
Ὅσων δʼ αἴτιον τὸ ἕνεκα τίνο— οἷον διὰ τί περιπατεῖ;
And for those things of which the cause is that for the sake of which—for example, why does he walk?
ὅπως ὑγιαίνῃ· διὰ τί οἰκία ἔστιν;
In order to be healthy; why is there a house?
ὅπwως σῴζηται τὰ σκεύη—τὸ μὲν ἕνεκα τοῦ ὑγιαίνειν, τὸ δʼ ἕνεκα τοῦ σῴζεσθαι.
In order that the utensils may be kept safe—the former is for the sake of being healthy, and the latter for the sake of keeping safe.
διὰ τί δὲ ἀπὸ δείπνου δεῖ περιπατεῖν, καὶ ἕνεκα τίνος δεῖ, οὐδὲν διαφέρει.
And it makes no difference why one must walk after dinner, and for the sake of what one must.
περίπατος ἀπὸ δείπνου Γ, τὸ μὴ ἐπιπολάζειν τὰ σιτία ἐφʼ οὗ Β, τὸ ὑγιαίνειν ἐφʼ οὗ Α. ἔστω δὴ τῷ ἀπὸ δείπνου περιπατεῖν ὑπάρχον τὸ ποιεῖν μὴ ἐπιπολάζειν τὰ σιτία πρός τῷ στόματι τῆς κοιλίας, καὶ τοῦτο ὑγιεινόν.
Let walking after dinner be Γ, food not floating on the surface of the stomach be B, and being healthy be A. Let there belong to walking after dinner the making of food not float at the mouth of the stomach, and let this be healthy.
δοκεῖ γὰρ ὑπάρχειν τῷ περιπατεῖν τῷ Γ τὸ Β τὸ μὴ ἐπιπολάζειν τὰ σιτία, τούτῳ δὲ τὸ Α τὸ ὑγιεινόν.
For B, food not floating, seems to belong to walking, Γ, and A, being healthy, to B.
τί οὗν αἵτιον τῷ Γ τοῦ τὸ Α ὑπάρχειν τὸ οὗ ἕνεκα;
What then is the cause for Γ of A belonging to it, that for the sake of which?
τὸ Β τὸ μὴ ἐπιπολάζειν.
It is B, not floating.
τοῦτο δ’ ἐστὶν ὥσπερ ἐκείνον λόγος· τὸ γὰρ Α οὕτως άροδοθήσεται.
And this is as it were the account of that (A); for A will be rendered in this way.
δυὶ τί δὲ τὸ Β τῷ Γ ἔστιν;
But why does B belong to Γ?
ὅτι τοῦτ’ ἔστι τὸ οὕτως ἕχεω.
Because to be in such a state is what this is.
δεῖ δὲ μεταλαμβάνειν τοὺς λόγους, καὶ οὕτως μᾶλλον ἕκαστα φανεῖται.
We must substitute the accounts, and in this way each thing will appear more clearly.
αἱ δὲ γενέσεις ἀνάπαλιν ἐνταῦθα καὶ ἐπὶ τῶν κατὰ κίνησιν αἰτίων· ἐκεῖ μὲν γὰρ τὸ μέσον δεῖ γενέσθαι πρῶτον, ἐνταῦθα δὲ τὸ Γ, τὸ ἔσχατον, τελευταῖον δὲ τὸ οὗ ἕνεκα.
But the comings-to-be here are in the reverse order compared to the causes in respect of motion; for there the middle term must come to be first, whereas here Γ, the extreme, is first, and that for the sake of which is last.
Ἐνδέχεται δὲ τὸ αὐτὸ καὶ ἕνεκά τινος εἶναι καὶ ἐξ ἀνάγκης, οἷον διὰ τοῦ λαμπτῆρος τὸ φῶς· καὶ γὰρ ἐξ ἀνάγκης διέρχεται τὸ μικρομερέστερον διὰ τῶν μειζόνων πόρων, εἴπερ φῶς γίνεται τῷ διιέναι, καὶ ἕνεκά τινος, ὅπως μὴ τπταίωμεν.
It is possible for the same thing to be both for the sake of something and from necessity, for example, the light through a lantern; for the finer-parted necessarily passes through the larger pores, if indeed light comes to be by passing through, and also for the sake of something, namely, so that we do not stumble.
ἆρʼ οὖν εἰ εἶναι ἐνδέχεται, καὶ γίνεσθαι ἐνδέχεται·
Is it then the case that if it is possible to be, it is also possible to come to be?
ὥσπερ εἰ βροντῶ 〈εὅτι〉 ἀποσβεννυμένου τε τοῦ πυρὸς ἀνάγκη σίζειν καὶ ψοφεῖν καί, εἰ ὡς οἱ Πυθαγόρειοί φασιν, ἀπειλῆς ἕνεκα τοῖς ἐν τῷ ταρτάρῳ, ὅπως φοβῶνται;
Just as if it thunders, both because the fire is extinguished it is necessary to hiss and crash, and, if it is as the Pythagoreans say, for the sake of threat to those in Tartarus, so that they may fear?
πλεῖστα δὲ τοιαῦτʼ ἔστι, καὶ μάλιστα ἐν τοῖς κατὰ φύσιν συνισταμένοις καὶ συνεστῶσιν· ἡ μὲν γάρ ἕνεκά του ποιεῖ φύσις, ἡ δʼ ἐξ ἀνάγκης.
Most such things exist, and especially among those things that are constituted and exist by nature; for nature acts on the one hand for the sake of something, and on the other hand from necessity.
ἡ δʼ ἀνάγκη διττή· ἡ μὲν γὰρ κατὰ φύσιν καὶ τὴν ἁρμήν, ἡ δὲ βίᾳ ἡ παρὰ τὴν ὁρμήν, ὥσπερ λίθος ἐξ ἀνάγκης καὶ ἄνω καὶ κάτω φέρεται, ἀλλʼ οὐ διὰ τὴν αὐτὴν ἀνάγκην.
And necessity is twofold: one according to nature and impulse, the other by force and contrary to impulse, as a stone is carried by necessity both upward and downward, but not through the same necessity.
ἐν δὲ τοῖς ἀπὸ διανοίας τὰ μὲν οὐδέποτε ἀπὸ τοῦ αὐτομάτου ὑπάρχει, οἷον οἰκία ἢ ἀνδριάς, οὐδʼ ἐξ ἀνάγκης, ἀλλʼ ἕνεκά του, τὰ δὲ καὶ ἀπὸ τύχης, οἷον ὑγίεια καὶ σωτηρία.
But among things from thought, some never exist by chance, such as a house or a statue, nor by necessity, but for the sake of something, while others also occur by luck, such as health and safety.
μάλιστα δὲ ἐν ὅσοις ἐνδέχεται καὶ ὧδε καὶ ἄλλως, ὅταν, μὴ ἀπὸ τύχης, ἡ γένεσις ἦ ὥστε τὸ τέλος ἀγαθόν, ἕνεκά του γίνεται, καὶ ἢ φύσει ἢ τέχνῃ.
Especially among those things that can be both thus and otherwise, when the coming-to-be is not by luck, so that the end is good, it comes to be for the sake of something, and either by nature or by art.
ἀπὸ τύχῆς δʼ οὐδὲν ἕνεκά του γίνεται.
But nothing comes to be for the sake of something by luck.