The brief passage on accidental unity (ἕv κατὰ συμβεβηκός) in Chapter 6 of Metaphysics Δ (1015b 16-34) raises a number of questions for which the text does not provide explicit answers. Aristotle does not define the nature of accidental unity, nor does he explain the status and character of the items which partake in accidental unities. One may wonder whether those items pertain to language, or to reality or whether they involve a certain relation of language to reality. Aristotle lists different examples which are purported to illustrate different kinds of accidental unity but those kinds are not described in general terms. Aristotle takes care, however, to explicate the conditions which underlie the specific use of each example of accidental unity. I want to argue first, on the basis of clues provided by the text itself, that the locus of accidental unities is not the real, or objective, realm but the linguistic one. However, though the items involved in accidental unities are linguistic, they bear a relation to reality because of their character as denoting expressions. I shall subsequently discuss the sense in which a unity is accidental. Finally, I shall provide an analysis of the different kinds of accidental unity associated with Aristotle's examples, and explain the senses in which accidental unity may relate to a universal.
Georgiadis, Constantine, "Aristotle on Unity: Metaphysics Delta 6" (1990). The Society for Ancient Greek Philosophy Newsletter. 260.