§1.2.9Ἐν δὲ τῷ δευτέρῳ σχήματι τὴν μὲν πρὸς τῷ μείζονι ἄκρῳ πρότασιν οὐκ ἔστιν ἀνελεῖν ἐναντίως, ὁποτερωσοῦν τῆς ἀντιστροφῆς γινομένης· ἀεὶ γὰρ ἔσται τὸ συμπέρασμα ἐν τῷ τρίτῳ σχήματι, καθόλου δʼ οὐκ ἦν ἐν τούτῳ συλλογισμός.
In the second figure, it is not possible to refute the premise containing the major extreme contrarily, whichever way the conversion is made; for the syllogism will always be in the third figure, but there was no universal syllogism in this.
τὴν δʼ ἑτέραν ὁμοίως ἀναιρήσομεν τῇ ἀντιστροφῇ.
But the other premise we shall refute in a manner corresponding to the conversion.
λέγω δὲ τὸ ὁμοίως, εἰ μὲν ἐναντίως ἀντιστρέφεται, ἐναντίως, εἰ δʼ ἀντικειμένως, ἀντικειμένως.
By 'in like manner' I mean: if it is converted contrarily, contrarily; if contradictorily, contradictorily.
ὑπαρχέτω γὰρ τὸ Α παντὶ τῷ Β, τῷ δὲ Γ μηδενί·
For let A belong to all B, and to no C: conclusion [B belongs to no] C.
συμπέρασμα Γ. ἐὰν οὖν ληφθῇ τὸ Β παντὶ τῷ Γ ὑπάρχειν καὶ τὸ. Α Β μένῃ, τὸ Α παντὶ τῷ Γ ὑπάρξει· γίνεται γὰρ τὸ πρῶτον σχῆμα.
If, then, B is assumed to belong to all C, and [the premise] AB remains, A will belong to all C; for the first figure is produced.
εἰ δὲ τὸ Β παντὶ τῷ Γ, τὸ δὲ Α μηδενὶ τῷ Γ, τὸ οὐ παντὶ τῷ Β· σχῆμα τὸ ἔσχατον.
But if B belongs to all C, and A to no C, [A belongs] not to all B: the last figure.
ἐὰν δʼ ἀντικειμένως ἀντιστραφῇ τὸ Β Γ, ἡ μὲν Β ὁμοίως δειχθήσεται, ἡ δὲ Γ ἀντικειμένως.
But if [the conclusion] BC is converted contradictorily, the [premise containing] B will be shown in like manner, and the [premise containing] C contradictorily.
εἰ γὰρ τὸ Β τινὶ τῷ Γ, τὸ δὲ μηδενὶ τῷ Γ, τὸ τινὶ τῷ Β οὐχ ὑπάρξει.
For if B belongs to some C, and [A] to no C, [A] will not belong to some B.
πάλιν εἰ τὸ Β τινὶ τῷ Γ, τὸ δὲ Α παντὶ τῷ Β, τὸ Α τινὶ τῷ Γ, ὥστʼ ἀντικείμενος γίνεται ὁ συλλογίσμός.
Again, if B belongs to some C, and A to all B, A will belong to some C, so that a contradictory syllogism is produced.
ὁμοίως δὲ δειχθήσεται καὶ εἰ ἀνάπαλιν ἔχοιεν αἱ προτάσεις.
And likewise will it be shown if the premises are conversely.
εἰ δʼ ἐστὶν ἐπὶ μέρους ὁ συλλογισμός, ἐναντίως μὲν ἀντιστρεφομένου τοῦ συμπεράσματος οὐδετέρα τῶν προτάσεων ἀναιρεῖται, καθάπερ οὐδʼ ἐν τῷ πρώτῳ σχήματι, ἀντικειμένως δʼ ἀμφότεραι.
But if the syllogism is particular, when the conclusion is converted contrarily, neither of the premises is refuted, just as in the first figure, but when contradictorily, both.
κείσθω γὰρ τὸ Α τῷ μὲν Β μηδενὶ ὑπάρχειν, τῷ δὲ Γ τινί συμπέρασμα Β Γ. ἐὰν οὖν τεθῇ τὸ Β τινὶ τῷ Γ ὑπάρχειν καὶ τὸ Β μένῃ, συμπέρασμα ἔσται ὅτι τὸ Α τινὶ τῷ Γ οὐχ ὑπάρχει, ἀλλʼ οὐκ ἀνήρηται τὸ ἐξ ἀρχῆς· ἐνδέχεται γὰρ τινὶ ὑπάρχειν καὶ μὴ ὑπάρχειν.
For let A be assumed to belong to no B, and to some C: conclusion BC. If, then, B is assumed to belong to some C, and [the premise] B remains, the conclusion will be that A does not belong to some C, but the original is not refuted; for it is possible to belong to some and not to belong.
πάλιν εἰ τὸ Β τινὶ τῷ Γ καὶ τὸ τινὶ τῷ Γ, οὐκ ἔσται συλλογισμός· οὐδέτερον γὰρ καθόλου τῶν εἰλημμένων ὥστ᾿ οὐκ ἀναιρεῖται τὸ Β. ἐὰν δʼ ἀντικειμένως ἀντιστρέφηται, ἀναιροῦνται ἀμφότεραι.
Again, if B belongs to some C, and [A] to some C, there will be no syllogism; for neither of the assumed [premises] is universal, so that [the premise] B is not refuted. But if it is converted contradictorily, both are refuted.
εἰ γὰρ τὸ Β παντὶ τῷ Γ, τὸ δὲ Α μηδενὶ τῷ Β, οὐδενὶ τῷ Γ τὸ Α· ἦν δὲ τινί.
For if B belongs to all C, and A to no B, A will belong to no C; but it was [assumed to belong] to some.
πάλιν εἰ τὸ Β παντὶ τῷ Γ. τὸ δὲ Α τινὶ τῷ Γ, τινὶ τῷ Β τὸ Α. ἡ αὐτὴ δʼ ἀπόδειξις καὶ εἰ τὸ καθόλου κατηγορικόν.
Again, if B belongs to all C, and A to some C, A will belong to some B. And the same proof [holds] also if the universal is affirmative.