Plato in the Protagoras suggests that the virtues are profoundly unified yet also distinct. In Plato on the Unity of the Virtues: A Dialectic Reading, Rod Jenks argues that the way in which they are both one and many is finally ineffable. He shows how, elsewhere in the corpus, Plato countenances ineffability. Jenks's interpretation of Protagoras accounts for the otherwise-inexplicable inability of both Socrates and Protagoras to identify the bone of contention between them. Not only can the thesis not be argued for; it can't even be properly stated. Jenks shows how the long exegesis on the...