Chapter 7
That is by nature prior which is implied in something else, while in itself it does not imply this; and which takes something else away when it itself is taken away, but is not necessarily taken away when the other is. For example, animal is by nature prior to man, for when the animal is taken away so as not to exist, then man will necessarily not exist either, because man is an animal. But, when man is taken away and does not exist, there can still be an animal —for there would be the horse and the dog and such, which are certain kinds of animals. Again, when man is postulated, then animal is most certainly implied with him, because man is an animal. But, when the animal is postulated, man is not necessarily implied, because, on the contrary, it might be a horse, or a dog, or something of the sort, for these are animals, too. Therefore, Peter is not by nature prior to Paul, nor is the rational animal prior to the irrational. For, when Peter is taken away so as not to exist, there will still be Paul. Likewise, when Paul is postulated, Peter is not implied with him; nor, when Peter is postulated, will Paul be implied. And neither is Peter more, that is to say, more a man or more an animal than Paul, nor is Paul more so than Peter. However, a drug may be found which is more healthful than another drug, and a book which is more medical than some other book.
[15] {Περὶ τοῦ φύσει προτέρου.} Φύσει οὖν πρότερόν ἐστι τὸ συνεισφέρον καὶ μὴ συνεισφερόμενον καὶ συναναιροῦν καὶ μὴ συναναιρούμενον, οἷον τὸ ζῷον φύσει πρότερόν ἐστι τοῦ ἀνθρώπου. Ἀναιρουμένου γὰρ καὶ μὴ ὄντος ζῴου ἐξ ἀνάγκης οὐδὲ ἄνθρωπος ἔσται: ζῷον γάρ ἐστιν ὁ ἄνθρωπος. Ἀνθρώπου δὲ ἀναιρουμένου καὶ μὴ ὄντος δυνατὸν εἶναι ζῷον: ἔσται γὰρ ἵππος, κύων καὶ τὰ τοιαῦτα, ἅτινα ζῷά εἰσι. Πάλιν εἰσφερομένου ἀνθρώπου πάντως καὶ ζῷον εἰσφέρεται: ζῷον γάρ ἐστιν ὁ ἄνθρωπος. Ζῴου δὲ εἰσφερομένου οὐ πάντως, ὅτι συνεισφέρεται ἄνθρωπος ἀλλ' ἵππος ἢ κύων ἤ τι τῶν τοιούτων: ζῷα γάρ εἰσι καὶ αὐτά. Οὔτε οὖν ὁ Πέτρος ἐστὶ φύσει πρότερος τοῦ Παύλου οὔτε τὸ λογικὸν ζῷον τοῦ ἀλόγου ζῴου. Πέτρου γὰρ ἀναιρουμένου καὶ μὴ ὄντος ἔσται Παῦλος: καὶ Παύλου εἰσφερομένου οὐ συνεισφέρεται Πέτρος, τοῦ δὲ Πέτρου συνεισφερομένου οὐ συνεισφέρεται Παῦλος, καὶ οὔτε Πέτρος ἐστὶ μᾶλλον ἤγουν πλέον τοῦ Παύλου ἄνθρωπος οὔτε Παῦλος τοῦ Πέτρου. Εὑρίσκεται δὲ φάρμακον ὑγιεινότερον φαρμάκου καὶ βιβλίον ἰατρικώτερον βιβλίου ἄλλου.