Note 162 — IV.

Ibid. b. 12-p. 123, a. 10. οὐδὲ δοκεῖ μετέχειν ἡ διαφορὰ τοῦ γένους· πᾶν γὰρ τὸ μετέχον τοῦ γένους ἢ εἶδος ἢ ἄτομόν ἐστιν. ἀεὶ γὰρ ἡ διαφορὰ ἐπ’ ἴσης ἢ ἐπὶ πλεῖον τοῦ εἴδους λέγεται. — ἐπὶ πλέον τε γὰρ τὸ γένος τῆς διαφορᾶς δεῖ λέγεσθαι, καὶ μὴ μετέχειν τῆς διαφορᾶς.

As an example to illustrate the enclosing of the genus within the species (εἰ τὸ γένος εἰς τὸ εἶδος ἔθηκεν), Aristotle cites a definition given by Plato, who defined τὴν κατὰ τόπον κίνησιν, as φοράν. Now φορὰ is less extensive in its meaning than ἡ κατὰ τόπον κίνησις, which includes βάδισις and other terms of motion apart from or foreign to φορά. — Example of enunciating differentia as a genus is, if immortal be given as the genus to which a god belongs. Immortal is the differentia belonging to ζῷον, and constituting therewith the species god. — Example of enclosing the differentia in the genus is, if odd be given as the essence of number (ὅπερ ἀριθμόν). — Example of enclosing differentia in the species is, if immortal be put forward as the essence of a god (ὅπερ θεόν). — Example of enclosing the genus in the differentia is, number given as the essence of the odd. — Example of enunciating the genus as a differentia is, when change of place is given as the differentia of φορά.