Authors/Aristotle/priora/Liber 2/C23

Chapter 23

Greek	Latin	English
	(PL 64 0708C) CAPUT XXIII. De epagoge, id est inductione.	23
68b8 ὅτι δ᾽ οὐ μόνον οἱ διαλεκτικοὶ καὶ ἀποδεικτικοὶ συλλογισμοὶ διὰ τῶν προειρημένων γίνονται σχημάτων, ἀλλὰ καὶ οἱ ῥητορικοὶ καὶ ἁπλῶς ἡτισοῦν πίστις καὶ ἡ καθ᾽ ὁποιανοῦν μέθοδον, νῦν ἂν εἴη λεκτέον. ἅπαντα γὰρ πιστεύομεν ἢ διὰ συλλογισμοῦ ἢ ἐξ ἐπαγωγῆς.	(0708D) Quoniam autem non solum dialectici et demonstrativi syllogismi per praedictas fiunt figuras, sed et rhetorici, sed et simpliciter quaecunque fides est, et secundum unamquamque artem, nunc erit dicendum. Omnia enim credimus per syllogismum aut ex inductione;	It is clear then how the terms are related in conversion, and in respect of being in a higher degree objects of aversion or of desire. We must now state that not only dialectical and demonstrative syllogisms are formed by means of the aforesaid figures, but also rhetorical syllogisms and in general any form of persuasion, however it may be presented. For every belief comes either through syllogism or from induction.
Ἐπαγωγὴ μὲν οὖν ἐστι καὶ ὁ ἐξ ἐπαγωγῆς συλλογισμὸς τὸ διὰ τοῦ ἑτέρου θάτερον ἄκρον τῶι μέσωι συλλογίσασθαι, οἷον εἰ τῶν Α Γ μέσον τὸ Β, διὰ τοῦ Γ δεῖξαι τὸ Α τῶι Β ὑπάρχον· οὕτω γὰρ ποιούμεθα τὰς ἐπαγωγάς. οἷον ἔστω τὸ Α μακρόβιον, τὸ δ᾽ ἐφ᾽ ὧι Β τὸ χολὴν μὴ ἔχον, ἐφ᾽ ὧι δὲ Γ τὸ καθ᾽ ἕκαστον μακρόβιον, οἷον ἄνθρωπος καὶ ἵππος καὶ ἡμίονος. τῶι δὴ Γ ὅλωι ὑπάρχει τὸ Α (πᾶν γὰρ τὸ Γ μακρόβιον)· ἀλλὰ καὶ τὸ Β, τὸ μὴ ἔχειν χολήν, παντὶ ὑπάρχει τῶι Γ.	ergo si inductio quidem est, et ex inductione syllogismus per alteram extremitatem medio syllogizare. Ut si eorum quae sunt A C medium sit B, per C ostendere A inesse B, sic enim facimus inductiones. Ut sit A longaevum, in quo autem B choleram non habere, in quo vero C singulare longaevum, ut homo, equus, et mulus. (0709A) Ergo toti B inest A, omne enim quod sibi cholera est, longaevum, sed et B non habere choleram, omni inest C;	Now induction, or rather the syllogism which springs out of induction, consists in establishing syllogistically a relation between one extreme and the middle by means of the other extreme, e.g. if B is the middle term between A and C, it consists in proving through C that A belongs to B. For this is the manner in which we make inductions. For example let A stand for long-lived, B for bileless, and C for the particular long-lived animals, e.g. man, horse, mule. A then belongs to the whole of C: for whatever is bileless is long-lived. But B also (’not possessing bile’) belongs to all C.
εἰ οὖν ἀντιστρέφει τὸ Γ τῶι Β καὶ μὴ ὑπερτείνει τὸ μέσον, ἀνάγκη τὸ Α τῶι Β ὑπάρχειν. δέδεικται γὰρ πρότερον ὅτι ἂν δύο ἄττα τῶι αὐτῶι ὑπάρχηι καὶ πρὸς θάτερον αὐτῶν ἀντιστρέφηι τὸ ἄκρον, ὅτι τῶι ἀντιστρέφοντι καὶ θάτερον ὑπάρξει τῶν κατηγορουμένων. δεῖ δὲ νοεῖν τὸ Γ τὸ ἐξ ἁπάντων τῶν καθ᾽ ἕκαστον συγκείμενον· ἡ γὰρ ἐπαγωγὴ διὰ πάντων.	si ergo convertatur C ei quod est B, et non transcendat medium, necesse est C inesse B. Ostensum enim est prius quoniam, si duo aliqua eidem insunt, et ad alteram eorum convertatur extremum, converso et alterum inerit praedicatorum. Oportet autem intelligere C ex singularibus omnibus compositum, nam inductio per omnia.	If then C is convertible with B, and the middle term is not wider in extension, it is necessary that A should belong to B. For it has already been proved that if two things belong to the same thing, and the extreme is convertible with one of them, then the other predicate will belong to the predicate that is converted. But we must apprehend C as made up of all the particulars. For induction proceeds through an enumeration of all the cases.
Ἔστι δ᾽ ὁ τοιοῦτος συλλογισμὸς τῆς πρώτης καὶ ἀμέσου προτάσεως· ὧν μὲν γὰρ ἔστι μέσον, διὰ τοῦ μέσου ὁ συλλογισμός, ὧν δὲ μὴ ἔστι, δι᾽ ἐπαγωγῆς. καὶ τρόπον τινὰ ἀντίκειται ἡ ἐπαγωγὴ τῶι συλλογισμῶι· ὁ μὲν γὰρ διὰ τοῦ μέσου τὸ ἄκρον τῶι τρίτωι δείκνυσιν, ἡ δὲ διὰ τοῦ τρίτου τὸ ἄκρον τῶι μέσωι. φύσει μὲν οὖν πρότερος καὶ γνωριμώτερος ὁ διὰ τοῦ μέσου συλλογισμός, ἡμῖν δ᾽ ἐναργέστερος ὁ διὰ τῆς ἐπαγωγῆς.	Syllogismus autem huiusmodi est primae et immediatae propositionis: quarum enim est medium, per medium est syllogismus; quorum vero non est, per inductionem. Et quodam modo opponitur inductio syllogismo, nam hic quidem per medium extremum de tertio ostendit, illa autem per tertium extremum de medio. Ergo natura quidem prior et notior per medium syllogismus, nobis autem manifestior qui est per inductionem.	Such is the syllogism which establishes the first and immediate premiss: for where there is a middle term the syllogism proceeds through the middle term; when there is no middle term, through induction. And in a way induction is opposed to syllogism: for the latter proves the major term to belong to the third term by means of the middle, the former proves the major to belong to the middle by means of the third. In the order of nature, syllogism through the middle term is prior and better known, but syllogism through induction is clearer to us.