Chapter 15
Every predicate is either more extensive than its subject or co-extensive with it, but it is never less extensive. It is more extensive when more general things are predicated of more particular ones. The more general, then, are the superior, whereas the more particular are the inferior. And the most general thing of all is the being, for which reason it is predicable of all things. For, substance is called a being, and so is accident called a being. But we cannot say that the being is substance, because not only is substance being, but so is accident. Genera, likewise, are predicable of their species, because they are more general; but the species are not predicable of their genera, because they are less general than their genera. Thus, substance is predicated of the animal, and the animal is predicated of man. This is because the animal is a substance and man is an animal. This is not, however, convertible, because, although every man is an animal, not every animal is a man—for the horse and the dog are animals, too. Moreover, not every substance is an animal, for stone and wood are substances which are not animals. Similarly, the species is predicable of the individuals contained in it, that is to say, of the individual substances, because the species is more general. But the individual, that is to say, the individual substance, is not predicable of the species, because the individual substance is more particular than its species. Thus, Peter is a man and Paul is a man, but not every man is Peter or Paul, because there are other persons contained in the human species. The differences also are predicable of the species in which they inhere and of their individuals. This is because the differences are more general than the species. Thus, the rational is more general than the species of man, because, although every man is rational, not every rational being is a man. Although the angel also is rational, he is not a man. Such, then, is the predicate which is more extensive.
The predicate, on the other hand, is co-extensive with its subject, when it is convertible. Thus, properties are predicated of the species of which they are properties; and the species are predicated of their properties. For every man is capable of laughter and everything that is capable of laughter is a man. Even though a monkey may also be said to laugh, it does not laugh with its heart but only with its features, because it is an animal which is good at mimicking. And so, the predication of the genera of their species, that of the differences of their species and that of the species of their individuals, are said to be more extensive; while that of the properties is said to be co-extensive. Those which are co-extensive are convertible and are called reciprocal predicables.
{Περὶ τῶν κατηγορουμένων.} Πᾶσα κατηγορία ἢ ἐπὶ πλέον γίνεται ἢ ἐπίσης, ἐπ' ἔλαττον δὲ οὐδέποτε. Καὶ ἐπὶ πλέον μέν, ὅτε τὰ καθολικώτερα κατηγοροῦνται τῶν μερικωτέρων: καθολικώτερα οὖν εἰσι τὰ ἐπάνω, μερικώτερα δὲ τὰ ὑποκάτω. Καθολικώτερον μὲν οὖν ἐστι πάντων τὸ ὄν, διὸ πάντων κατηγορεῖται: καὶ γὰρ καὶ ἡ οὐσία ὂν λέγεται καὶ τὸ συμβεβηκὸς ὂν λέγεται. Οὐ δυνάμεθα δὲ εἰπεῖν, ὅτι τὸ ὂν οὐσία ἐστίν: οὐ μόνον γὰρ οὐσία ἐστὶ τὸ ὂν ἀλλὰ καὶ συμβεβηκός. Ὁμοίως καὶ τὰ γένη κατηγοροῦνται τῶν εἰδῶν ὡς καθολικώτερα, τὰ δὲ εἴδη οὐ κατηγοροῦνται τῶν γενῶν αὐτῶν: τὰ γὰρ εἴδη μερικώτερα τῶν γενῶν εἰσι. Κατηγορεῖται τοίνυν ἡ οὐσία τοῦ ζῴου καὶ τὸ ζῷον τοῦ ἀνθρώπου: καὶ γὰρ τὸ ζῷον οὐσία ἐστὶ καὶ ὁ ἄνθρωπος ζῷόν ἐστιν. Οὐκ ἀντιστρέφει δέ: πᾶς μὲν γὰρ ἄνθρωπος ζῷον, οὐ πᾶν δὲ ζῷον ἄνθρωπος. Καὶ ὁ ἵππος γὰρ καὶ ὁ κύων ζῷά εἰσιν, ὁμοίως καὶ πᾶν ζῷον οὐσία ἐστίν, οὐ πᾶσα δὲ οὐσία ζῷόν ἐστιν: καὶ ὁ λίθος γὰρ καὶ τὸ ξύλον οὐσία ἐστίν, ἅτινα οὔκ εἰσι ζῷα. Ὁμοίως καὶ τὸ εἶδος κατηγορεῖται τῶν ὑπ' αὐτοῦ περιεχομένων ἀτόμων τουτέστιν ὑποστάσεων ὡς καθολικώτερον. Τὸ δὲ ἄτομον ἤγουν ἡ ὑπόστασις οὐ κατηγορεῖται τοῦ εἴδους: μερικωτέρα γάρ ἐστι τοῦ εἴδους ἡ ὑπόστασις. Καὶ Πέτρος τοίνυν ἄνθρωπός ἐστι καὶ Παῦλος ἄνθρωπός ἐστιν, οὐ πᾶς δὲ ἄνθρωπος Πέτρος ἢ Παῦλος: εἰσὶ γὰρ καὶ ἄλλαι ὑποστάσεις ὑπὸ τὸ εἶδος τοῦ ἀνθρώπου. Καὶ αἱ διαφοραὶ δὲ κατηγοροῦνται τῶν εἰδῶν, οἷς ἐνυπάρχουσι, καὶ τῶν ἀτόμων αὐτῶν. Καθολικώτεραι γάρ εἰσιν αἱ διαφοραὶ τῶν εἰδῶν: τὸ γὰρ λογικὸν καθολικώτερόν ἐστι τοῦ εἴδους τοῦ ἀνθρώπου. Καὶ γὰρ πᾶς μὲν ἄνθρωπος λογικός, οὐ πᾶς δὲ λογικὸς ἄνθρωπος: καὶ ὁ ἄγγελος γὰρ λογικὸς ὢν οὐκ ἔστιν ἄνθρωπος. Καὶ αὕτη μέν ἐστιν ἡ ἐπὶ πλέον κατηγορία: ἡ δὲ ἐπίσης κατηγορία, ὅτε ἀντιστρέφει. Κατηγοροῦνται γὰρ τὰ ἴδια τῶν εἰδῶν, ὧν ἐστιν ἴδια, ἀλλὰ καὶ τὰ εἴδη κατηγοροῦνται τῶν ἰδίων αὐτῶν: πᾶς γὰρ ἄνθρωπος γελαστικός, καὶ πᾶς γελαστικὸς ἄνθρωπος. Εἰ γὰρ καὶ γελᾶν λέγεται πίθηκος, οὐ γελᾷ τῇ καρδίᾳ ἀλλὰ τοῖς σχήμασι: μιμητικὸν γὰρ ζῷόν ἐστιν. Ὥστε ἡ μὲν τῶν γενῶν κατὰ τῶν εἰδῶν κατηγορία καὶ ἡ τῶν διαφορῶν κατὰ τῶν εἰδῶν καὶ ἡ τῶν εἰδῶν κατὰ τῶν ἀτόμων ἐπὶ πλέον λέγεται, ἡ δὲ τῶν ἰδίων ἐπίσης. Ταῦτα δὲ τὰ ἐπίσης ἀντιστρέφοντα καὶ ἀντικατηγορούμενα λέγονται.