Chapter 17

Predication of the essence of a thing is one thing, whereas that of its sort is another. Predication is of the essence of a thing when, being asked what a man is, we reply: ‘an animal.’ But it is of its sort when, being asked what sort of an animal, we answer: ‘a rational mortal animal.’ Thus, the genus and the species are predicated of the essence of a thing; whereas the difference, whether essential—that is to say, whether property or accident—is predicated of its sort. The individual substance neither signifies what the thing is nor of what sort it is, but it does signify which one it is. Thus, when we are asked who this man is, we reply that he is Peter. Then, when asked what sort of man he is, we reply that he is tall, let us say, or short.

(Moreover, one should know that things which differ in nature are said to be one thing and another. Thus, we say that man is one thing and the horse another, and we mean another thing in nature, because the species of man is one thing and that of the horse is something else. Those things, however, which differ in number, that is to say, which are individual substances, are said to be one and another. Thus, we say that Peter is one and Paul another. However, we cannot say that Peter is one and Paul another, because, if we did, we should not be telling the truth. For in nature they are one thing, but numerically they are not.

And one should know that the substance is called another thing, and likewise the essential differences, while the accident is called something of another sort. This is because the essential differences are considered in connection with the species, that is to say, in connection with the nature which they go to make up. The accident is considered in connection with the individual, because the accidents are constituent of the individual substance. A man, then, is one thing and a horse another, but Peter is of one sort and one and Paul of another sort and another. Moreover, every difference, whether essential or not, makes for something else of a different sort, for ἑτεροῖον means both something else and a thing of a different sort. The nature, then, signifies what a thing is, whereas the individual substance specifies this certain person or thing and every difference shows of what sort something is.)

[11] {Περὶ τῆς ἐν τῷ τί ἐστι κατηγορίας καὶ τῆς ἐν τῷ ὁποῖόν τί ἐστι κατηγορίας.} Ἄλλο ἐστὶν ἡ ἐν τῷ τί ἐστι κατηγορία καὶ ἄλλο ἡ ἐν τῷ ὁποῖόν τί ἐστι: καὶ ἡ ἐν τῷ τί ἐστι μέν, ὅτε ἐρωτώμενοι ‘τί ἐστιν ἄνθρωπος’ λέγομεν ‘ζῷον’: ἐν δὲ τῷ ὁποῖόν τί ἐστιν, ὅτε ἐρωτώμενοι ‘ὁποῖον ζῷον’ φαμὲν ‘λογικὸν θνητόν’. Ὥστε τὸ μὲν γένος καὶ τὸ εἶδος ἐν τῷ τί ἐστι κατηγορεῖται, ἡ δὲ διαφορὰ ἥ τε οὐσιώδης καὶ ἡ ἐπουσιώδης ἤγουν τὸ συμβεβηκὸς καὶ τὸ ἴδιον ἐν τῷ ὁποῖόν τί ἐστι κατηγοροῦνται. Ἡ δὲ ὑπόστασις οὐδὲ τί ἐστι δηλοῖ οὐδὲ ὁποῖόν τί ἐστιν, ἀλλὰ τίς ἐστιν: ἐρωτώμενοι γὰρ ‘τίς ἐστιν οὗτος’ λέγομεν ‘Πέτρος’. Εἶτα ἐρωτώμενοι ‘τί ἐστι Πέτρος’ λέγομεν ‘ἄνθρωπος’. Πάλιν ἐρωτώμενοι ‘ὁποῖος ἄνθρωπος’ λέγομεν ‘μακρὸς τυχὸν ἢ κολοβός’. Χρὴ δὲ γινώσκειν, ὅτι τὰ φύσει διαφέροντα ἄλλο καὶ ἄλλο λέγονται. Λέγομεν γάρ: Ἄλλο ἐστὶν ἄνθρωπος καὶ ἄλλο ἵππος, ἄλλο δὲ κατὰ φύσιν: καὶ γὰρ ἕτερον εἶδος τοῦ ἀνθρώπου καὶ ἄλλο τοῦ ἵππου. Τὰ δὲ ἀριθμῷ διαφέροντα ἤγουν αἱ ὑποστάσεις ἄλλος καὶ ἄλλος λέγονται. Λέγομεν γάρ, ὅτι ἄλλος ἐστὶν ὁ Πέτρος καὶ ἄλλος ὁ Παῦλος. Οὐ δυνάμεθα δὲ εἰπεῖν, ὅτι ἄλλο ἐστὶ Πέτρος καὶ ἄλλο Παῦλος, ἐπεὶ ψευδόμεθα: ἓν γάρ εἰσι τῇ φύσει, οὔκ εἰσι δὲ εἷς τῷ ἀριθμῷ. Δεῖ δὲ γινώσκειν, ὅτι ἡ μὲν οὐσία ἄλλο καλεῖται, ὁμοίως καὶ αἱ οὐσιώδεις διαφοραί, τὸ δὲ συμβεβηκὸς ἀλλοῖον, διότι αἱ μὲν οὐσιώδεις διαφοραὶ περὶ τὸ εἶδος ἤγουν περὶ τὴν φύσιν θεωροῦνται καὶ ταύτην συνιστῶσι, τὸ δὲ συμβεβηκὸς περὶ τὸ ἄτομον: συστατικὰ γὰρ τῆς ὑποστάσεως τὰ συμβεβηκότα. Ἄλλο οὖν ἐστιν ἄνθρωπος καὶ ἄλλο ἵππος, ἀλλοῖος δὲ καὶ ἄλλος ὁ Πέτρος καὶ ἀλλοῖος καὶ ἄλλος ὁ Παῦλος. Πᾶσα δὲ διαφορὰ οὐσιώδης τε καὶ ἐπουσιώδης ἑτεροῖον ποιεῖ: τὸ γὰρ ἑτεροῖον σημαίνει καὶ τὸ ἄλλο καὶ τὸ ἀλλοῖον. Καὶ ἡ μὲν φύσις τὸ τί σημαίνει, ἡ δὲ ὑπόστασις τὸν τινὰ καὶ τόδε τι. Πᾶσα δὲ διαφορὰ ὁποῖόν ἐστιν.