Abstract

In Plato's middle period, the Old Academic Dichotomy $ performed the function of distinguishing the Forms from the perceptibles, whereas in his late period it assisted in an extensive plan of "relativization" of the Forms themselves . At the same time, it enabled him to address some troublesome paradoxes that concern existence/non-existence, predication itself, indeed the very problems Aristotle resolved with the aid of the categories. ;For Aristotle, I claim, the OAD not only provided the inspiration for the essence/accident distinction, but that the "deep structure", as it were, of the categories can best be understood as predications which involve the OAD. For example, an accidental predication presupposes a reference to another: "Socrates is white" presupposes the predication "Something in Socrates is white $\kappa\alpha\theta$' $\alpha\upsilon\tau\acute o$." ;Thus, when the scope of the OAD is confined to predicates, the result is the Aristotelian categories. ;When the scope is confined to being, and in particular the "is" of predication, the OAD renders us the existential "is" and the copulative "is" . The view I take here is contrary to the view of G. E. L. Owen, who tries to reduce the existential "is" to the predicative "is". ;Finally, when the scope is confined to the $\varepsilon\iota\delta o\varsigma$, or form, the OAD renders first the ontological form, the part that is in the subjects, e.g. the soul, and, second, the universal, the indeterminate whole, that is said of the subject but not in the subject, e.g. man. The equivocal use of $\varepsilon\iota\delta o\varsigma$ in Met. ZH$\Theta$ may not be pernicious, an indication that Aristotle was confused. ;By paying attention to the scope $ one can see how the OAD elucidates some inveterate problems in Aristotle