Abstract

Common (κοινὸν) has the following features in Aristotle’s works: 1. ‘That which is common ὑπαρχει in many things at the same time,’ which show that it cannot be one thing because that which is one cannot be in many things at the same time. (Met. , Z, 1040b25-27) Although the common is common between different things, it is indeed different for each of them (ἓτερον ἑκατέρῳ τοῦτο αὐτο τὸ ζῷον). Animal, e.g., which is common between horse and man, is specifically different in them (τὸ κοινὸν ἓτερον ἀλλήλων ἐστὶ τῷ εἴδει). Thus, man and horse are different having difference of genus, an otherness that makes the genus itself different (ἀνάγκη ἄρα τὴν διαφορὰν ταύτην ἑτερότητα τοῦ γένους εἶναι. λέγω γὰρ γένους διαφορὰν ἑτερότητα ἣ ἓτερον ποιεῖ τοῦτο αὐτό). (Met., I, 1058a2-8) 2. The common indicates a ‘such’ (τοιόνδε) and not a ‘this’ (τόδε τι). (Met., B, 1003a7-9) One reason of this is that every single thing has several commons with other things and if each of these commons were to be a this, every single thing would be several things. (Met., B, 1003a9-12; cf. Met., Z, 1038b34-1039a11) 3. To investigate the definition of a thing, we must stablish the common element in all members of all the species of that which is to be defined and the common of the commons until we reach to a single formula, which will be the definition. (PsA., B, 13, 97b7-13) The same is true about the investigation of essential nature: to inquire the essential nature of a thing, we should search for what is common in instances. (PsA., B, 13, 97b15-25) 4. The process of the selection of analyses and divisions is based on lying down the common genus of all the subjects of investigation by analyzing the common properties and especially essential properties of subgenera classes. (psA., B, 14, 98a1-12) 5. We must distinguish between two ways of commonship: being based on a common (καθ᾿ ἓν) or being related to or referred to a common (πρὸς ἓν or πρὸς μίαν). (Met., B, 1003b12-15) 6. Things that have common nature, fall under one science. (Met., K, 1060b33-36)