Plato on the Goodness of Difference: The Convertibility of the Transcendentals in the Sophist

This article argues that Plato’s Sophist can be understood as promoting a rudimentary version of the medieval notion of the “convertibility of the transcendentals,” that is, that there are certain properties of being, such as unity and truth, that have the same extension as being but add conceptual content to being. Histories of the doctrine of the transcendentals tend to trace transcendental thought back no earlier than Aristotle and thus ignore the relevance of Plato generally and the Sophist specifically. This article argues that the Eleatic Stranger’s discourse on the five “greatest kinds” (megista genē) indicates that Sameness and Otherness fulfill the criteria of transcendentality. The article uses this analysis to provide an avenue for further study of Platonic metaphysics in the hope that the notion of “convertibility of the transcendentals” will aid interpreters in understanding how to bring together Plato’s various accounts of what is metaphysically ultimate. This article suggests that, in addition to sameness and otherness, unity, goodness, truth, and beauty are also transcendentals within Platonic metaphysics. The article concludes by implying that difference (i.e., Otherness) must be ontologically good in Platonic thought, contrary to the common criticism that Platonism both denigrates difference and subordinates it to sameness.