  So read, the midwife passage can also tell us something important about the limitations of the Theaetetus’ inquiry. The limitations of the inquiry are the limitations of the main inquirers, and neither (the historical) Socrates nor Theaetetus was a card-carrying adherent of Plato’s theory of Forms. Perhaps the dialogue brings us only as far as the threshold of the theory of Forms precisely because, on Socratic principles, one can get no further. To get beyond where the Theaetetus leaves off, you have to be a Platonist. (For book-length developments of this reading of the Theaetetus, see Sedley 2004 and Chappell 2005.)