 No doubt, some of the works widely considered to be early really are such. But it is an open question which and how many of them are. At any rate, it is clear that Plato continued to write in a “Socratic” and “negative” vein even after he was well beyond the earliest stages of his career: Theaetetus features a Socrates who is even more insistent upon his ignorance than are the dramatic representations of Socrates in briefer and philosophically less complex works that are reasonably assumed to be early; and like many of those early works, Theaetetus seeks but does not find the answer to the “what is it?” question that it relentlessly pursues—“What is knowledge?” Similarly, Parmenides, though certainly not an early dialogue, is a work whose principal aim is to puzzle the reader by the presentation of arguments for apparently contradictory conclusions; since it does not tell us how it is possible to accept all of those conclusions, its principal effect on the reader is similar to that of dialogues (many of them no doubt early) that reach only negative conclusions. Plato uses this educational device—provoking the reader through the presentation of opposed arguments, and leaving the contradiction unresolved—in Protagoras (often considered an early dialogue) as well. So it is clear that even after he was well beyond the earliest stages of his thinking, he continued to assign himself the project of writing works whose principal aim is the presentation of unresolved difficulties. (And, just as we should recognize that puzzling the reader continues to be his aim even in later works, so too we should not overlook the fact that there is some substantive theory-construction in the ethical works that are simple enough to have been early compositions: Ion, for example, affirms a theory of poetic inspiration; and Crito sets out the conditions under which a citizen acquires an obligation to obey civic commands. Neither ends in failure.)