Again - this is the book to read on Plato's Theaetetus and Sophist. There is also a very brilliant essay by Father Diès (who was a great Platonist) in the Budé editions:http://www.lesbelleslettres.com/livre/?GCOI=22510100359860http://www.lesbelleslettres.com/livre/?GCOI=22510100221030One of the bes...