4Τὰς δὴ τῆς ψυχῆς ἀρετὰς διελόμενοι τὰς μὲν35 εἶναι τοῦ ἤθους ἔφαμεν τὰς δὲ τῆς διανοίας.1139 a περὶ μὲν οὖν τῶν ἠθικῶν διεληλύθαμεν, περὶ δὲ τῶν λοιπῶν, περὶ ψυχῆς πρῶτον εἰπόντες, λέγωμεν 5οὕτως. πρότερον μὲν οὖν ἐλέχθη δύ᾿ εἶναι μέρη τῆς ψυχῆς, τό τε λόγον ἔχον καὶ τὸ ἄλογον· νῦν5 δὲ περὶ τοῦ λόγον ἔχοντος τὸν αὐτὸν τρόπον διαιρετέον, καὶ ὑποκείσθω δύο τὰ λόγον ἔχοντα, ἓν μὲν ᾧ θεωροῦμεν τὰ τοιαῦτα τῶν ὄντων ὅσων αἱ ἀρχαὶ μὴ ἐνδέχονται ἄλλως ἔχειν, ἓν δὲ ᾧ τὰ ἐνδεχόμενα· πρὸς γὰρ τὰ τῷ γένει ἕτερα καὶ τῶν τῆς ψυχῆς μορίων ἕτερον τῷ γένει τὸ πρὸς ἑκάτερον10 πεφυκός, εἴπερ καθ᾿ ὁμοιότητά τινα καὶ οἰκειότητα 6ἡ γνῶσις ὑπάρχει αὐτοῖς. λεγέσθω δὲ τούτων τὸ μὲν ἐπιστημονικὸν τὸ δὲ λογιστικόν· τὸ γὰρ βουλεύεσθαι καὶ λογίζεσθαι ταὐτόν, οὐθεὶς δὲ βουλεύεται περὶ τῶν μὴ ἐνδεχομένων ἄλλως ἔχειν, ὥστε τὸ λογιστικόν ἐστιν ἕν τι μέρος τοῦ15 7λόγον ἔχοντος. ληπτέον ἄρ᾿ ἑκατέρου τούτων τίς ἡ βελτίστη ἕξις· αὕτη γὰρ ἀρετὴ ἑκατέρου.
ii ἡ δ᾿ ἀρετὴ πρὸς τὸ ἔργον τὸ οἰκεῖον. τρία δ᾿ ἐστὶν ἐν τῇ ψυχῇ τὰ κύρια πράξεως καὶ ἀληθείας,
it is not enough merely to have established the truth of the above formula; we also have to define exactly what the right principle is, and what is the standard that determines it.a
4Now we have divided the Virtues of the Soul into two groups, the Virtues of the Character and the Virtues of the Intellect. The former, the Moral Virtues, we have already discussed. Our account of the latter must be prefaced by some remarks about psychology.
5It has been said beforeb that the soul has twoThe Intellectual Virtues are two subdivisions of the rational part of the Soul, the Scientific Faculty and the Calculative or Deliberative Faculty. parts, one rational and the other irrational. Let us now similarly divide the rational part, and let it be assumed that there are two rational faculties, one whereby we contemplate those things whose first principles are invariable, and one whereby we contemplate those things which admit of variation: since, on the assumption that knowledge is based on a likeness or affinity of some sort between subject and object, the parts of the soul adapted to the cognition of objects that are of different kinds must 6themselves differ in kind. These two rational faculties may be designated the Scientific Faculty and the Calculative Faculty respectively; since calculation is the same as deliberation, and deliberation is never exercised about things that are invariable, so that the Calculative Faculty is a separate part of the rational half of the soul.
7We have therefore to ascertain what disposition of each of these faculties is the best, for that will be the special virtue of each.
But the virtue of a faculty is related to the special
iifunction which that faculty performs. Now there are three elements in the soul which control action