Self-knowledge has always been a central topic of philosophical inquiry. It is hard to think of a major philosopher, from ancient times to the present, who refrained from pronouncing on the nature, the importance, or the limitations of one's knowing of oneself as oneself. What makes self-knowledge such a perplexing phenomenon? The essays featured in this collection seek to deepen our understanding of self-knowledge, to solve some of the genuine (and to resolve some of the spurious) problems that hold back philosophical progress on that front, and to assess the value of some classic moves in the debate over the epistemic status of self-ascriptions. Some of the chapters discuss features of self-knowledge that appear to account for its unique -- and, in that sense, peculiar -- status; some advance straight for solving crucial problems; and others take a step back to consider the terms in which we set the questions to which a philosophical theory of self-knowledge is to provide the answer. Through their rigorous argumentation regarding the issues of reflection, introspection, deliberation, rationality, belief-formation, and epistemic warrant, the contributors illustrate how the specific problems that surround the topic of self-knowledge, instead of being approached as peripheral cases to which ready-made epistemological theories can be applied, may themselves illuminate some fundamental issues in the theory of knowledge.