Definitional Structure and the Same, the Different, and Part-Whole Relations in Plato’s Parmenides

Abstract

This article argues that the second part of the Parmenides (137-166) consists not only of the well-known logical structure that has been widely studied but also of a great variety of definitions of forms. My aim is to show how these definitions depend on a specific group of closely connected primary forms (i.e., same, different, part, whole). The definitions that Parmenides provides help Socrates overcome his failure in attempting to define forms in the first part of the dialogue.