Chapter 13
An accident is that which may either be present or absent without destroying the subject. Again, it is that which can be or not be in the same thing. Thus, it is possible for a man to be white or not, and also for him to be tall, intelligent, or flat-nosed or not. (For the presence of this does not save the species, because it does not belong to the definition of the species. Neither does its absence destroy the species. Thus, even though the Ethiopian is not white, this in no wise keeps him from being a man. And so, whether it is present or absent, it does not injure the subject substance—for we have said that the substance is a subject and sort of matter for the accidents.)
The accident is divided into two kinds: that which is commonly called a difference and that which is properly a difference. What is commonly called a difference is the separable accident. For example, one person is seated and another standing. Now, by the standing up of the one who is seated and the sitting down of the one who is standing it is possible for the original difference between the two to be removed and replaced by another difference. And one is also said to differ from oneself by a separable accident, for one does differ from oneself by sitting down and standing, by being young and growing old, by being sick and getting well, and so forth. A difference in the proper sense is the inseparable accident. For example, a person is snub-nosed and it is impossible to separate his snub-nosedness from him, and similarly with his being gray-eyed and the like. Thus, it is by these inseparable accidents that one individual, that is, one individual substance, differs from another. However, one’s own self never differs from oneself. Now, the accidents do not enter into the definition (of the nature), because it is possible for a man to be snub-nosed or not, and, just because a man does not have gray eyes, he remains no less a man.
[07] {Περὶ συμβεβηκότος.} Συμβεβηκός ἐστιν, ὃ γίνεται καὶ ἀπογίνεται χωρὶς τῆς τοῦ ὑποκειμένου φθορᾶς. Καὶ πάλιν, ὃ ἐνδέχεται τῷ αὐτῷ καὶ εἶναι καὶ μὴ εἶναι: καὶ γὰρ ἐνδέχεται ἄνθρωπον καὶ λευκὸν εἶναι καὶ μὴ εἶναι λευκόν, ὁμοίως καὶ μακρὸν καὶ φρόνιμον καὶ σιμόν. Τοῦτο τὸ συμβεβηκὸς διαιρεῖται εἰς δύο, εἰς τὴν κοινῶς λεγομένην διαφορὰν καὶ εἰς τὴν ἰδίως διαφοράν. Κοινῶς μὲν οὖν διαφορά ἐστι τὸ χωριστὸν συμβεβηκός, οἷον κάθηταί τις καὶ ἕτερος ἵσταται: ἐνδέχεται ἐν τῷ ἀναστῆναι τὸν καθήμενον καὶ καθίσαι τὸν ἱστάμενον χωρισθῆναι τὴν διαφορὰν αὐτῶν καὶ λαβεῖν ἄλλην ἀντ' ἄλλης. Καὶ ἑαυτοῦ δέ τις λέγεται διαφέρειν κατὰ τὸ χωριστὸν συμβεβηκός: διαφέρει γὰρ ἑαυτοῦ ἐν τῷ καθῆσθαι καὶ ἀνίστασθαι, ἐν τῷ νεάζειν καὶ γηρᾶν, ἐν τῷ νοσεῖν καὶ ὑγιαίνειν καὶ τοῖς τοιούτοις. Ἰδίως δὲ διαφορά ἐστι τὸ ἀχώριστον συμβεβηκός, οἷόν ἐστί τις σιμός: ἀδύνατον χωρισθῆναι αὐτοῦ τὴν σιμότητα, ὁμοίως καὶ τὴν γλαυκότητα καὶ τὰ τοιαῦτα. Κατὰ ταῦτα οὖν τὰ ἀχώριστα συμβεβηκότα ἄτομον ἀτόμου τουτέστιν ὑπόστασις ὑποστάσεως διαφέρει, αὐτὸς δὲ ἑαυτοῦ οὐδέποτε. Ταῦτα δὲ οὐ συντελοῦσιν εἰς τὸν ὁρισμὸν τῆς φύσεως: ἐνδέχεται γὰρ ἄνθρωπον εἶναι σιμὸν καὶ μὴ εἶναι. Καὶ ἀπογινομένης τῆς γλαυκότητος οὐδὲν ἧττον ὁ ἄνθρωπος μένει ἄνθρωπος.