[112] Diog. 41: τὸ δὲ λογικὸν μέρος φασὶν ἔνιοι εἰς δύο διαιρεῖσθαι ἐπιστήμας, εἰς ῥητορικὴν καὶ διαλεκτικήν ... τήν τε ῥητορικὴν ἐπιστήμην οὖσαν τοῦ εὖ λέγειν περὶ τῶν ἐν διεξόδῳ λόγων καὶ τὴν διαλεκτικὴν τοῦ ὀρθῶς διαλέγεσθαι περὶ τῶν ἐν ἐρωτήσει καὶ ἀποκρίσει λόγων. Sen. Ep. 89, 17: Superest ut rationalem partem philosophiæ dividam: omnis oratio aut continua est aut inter respondentem et interrogantem discissa; hanc διαλεκτικὴν, illam ῥητορικὴν placuit vocari. Cic. Fin. ii. 6, 17; Orat. 32, 113. Quintil. Inst. ii. 20, 7. According to these passages, Rhetoric was by Zeno compared to the palm of the hand, and Dialectic to the fist: quod latius loquerentur rhetores, dialectici autem compressius. The Stoics agree with Aristotle in calling rhetoric ἀντίστροφος τῇ διαλεκτικῇ (Sop. in Hermog. v. 15, Walz.). See Prantl, Gesch. der Log. i. 413. [113] Diog. 41: Some divide logic into rhetoric and dialectic: τινὲς δὲ καὶ εἰς τὸ ὁρικὸν εἶδος, τὸ περὶ κανόνων καὶ κριτηρίων· ἔνιοι δὲ τὸ ὁρικὸν περιαιροῦσι. (We have no reason to read as Ménage does περιδιαιροῦσι, or to conjecture, as Meibom and Nicolai, De Log. Chrys., Lib. 23, do, παραδιαιροῦσι.) According to this passage, ὁρικὸν must be identical with the doctrine of a criterium. In a subsequent passage, however, the two are distinguished; the doctrine of a criterium is said to be useful for the discovery of truth: καὶ τὸ ὁρικὸν δὲ ὁμοίως πρὸς ἐπίγνωσιν τῆς ἀληθείας· διὰ γὰρ τῶν εὐνοιῶν τὰ πράγματα λαμβάνεται. We may therefore suppose that in the passage first quoted the words should be τὸ ὁρικὸν εἶδος καὶ τὸ περὶ κανόνων, κ.τ.λ. In this case, we may understand by ὁρικὸν not only the theory of definition—a theory to which Aristotle devoted a separate section at the end of his Analytics (Anal. Post. ii.)—but besides a theoretical disquisition on the formation of definitions, a collection of definitions of various objects. Such collections are found in the treatises of Chrysippus (Diog. 199, 189): περὶ τῶν ὅρων ζʹ. ὅρων διαλεκτικῶν στʹ. ὅρων τῶν κατὰ γένος ζʹ. ὅρων τῶν κατὰ τὰς ἄλλας τέχνας αβʹ. ὅρων τῶν τοῦ ἀστείου βʹ. ὅρων τῶν τοῦ φαύλου βʹ. ὅρων τῶν ἀναμέσων βʹ; besides the further treatises περὶ τῶν οὐκ ὀρθῶς τοῖς ὅροις ἀντιλεγομένων ζʹ. Πιθανὰ εἰς τοὺς ὅρους βʹ. The treatise περὶ εἰδῶν καὶ γενῶν βʹ may also be included here; perhaps also that περὶ τῶν κατηγορημάτων πρὸς Μητρόδωρον ιʹ. πρὸς Πάσυλον περὶ κατηγορημάτων δʹ, Diog. 191.