 Although these propositions are often identified by Plato’s readers as forming a large part of the core of his philosophy, many of his greatest admirers and most careful students point out that few, if any, of his writings can accurately be described as mere advocacy of a cut-and-dried group of propositions. Often Plato’s works exhibit a certain degree of dissatisfaction and puzzlement with even those doctrines that are being recommended for our consideration. For example, the forms are sometimes described as hypotheses (see for example Phaedo). The form of good in particular is described as something of a mystery whose real nature is elusive and as yet unknown to anyone at all (Republic). Puzzles are raised—and not overtly answered—about how any of the forms can be known and how we are to talk about them without falling into contradiction (Parmenides), or about what it is to know anything (Theaetetus) or to name anything (Cratylus). When one compares Plato with some of the other philosophers who are often ranked with him—Aristotle, Aquinas, and Kant, for example—he can be recognized to be far more exploratory, incompletely systematic, elusive, and playful than they. That, along with his gifts as a writer and as a creator of vivid character and dramatic setting, is one of the reasons why he is often thought to be the ideal author from whom one should receive one’s introduction to philosophy. His readers are not presented with an elaborate system of doctrines held to be so fully worked out that they are in no need of further exploration or development; instead, what we often receive from Plato is a few key ideas together with a series of suggestions and problems about how those ideas are to be interrogated and deployed. Readers of a Platonic dialogue are drawn into thinking for themselves about the issues raised, if they are to learn what the dialogue itself might be thought to say about them. Many of his works therefore give their readers a strong sense of philosophy as a living and unfinished subject (perhaps one that can never be completed) to which they themselves will have to contribute. All of Plato’s works are in some way meant to leave further work for their readers, but among the ones that most conspicuously fall into this category are: Euthyphro, Laches, Charmides, Euthydemus, Theaetetus, and Parmenides.