This chapter serves as an introduction to the only extant collection of essays on the themes of self-knowledge and self-ignorance in Platonic philosophy. The authors argue for the centrality of this topic in Plato’s thought and point to ample evidence of revived interest among Plato scholars in the secondary literature: papers, monographs, and symposia on the topic are increasingly thick on the ground. They also highlight the enduring importance of Plato’s conception of the self for contemporary discourses on subjectivity. It is not that self-knowledge has only now been discovered as an important Platonic theme. This is hardly plausible when dealing with a writer whose most famous literary creation describes his entire philosophical career as an act of interrogative obedience to the Delphic imperative. What is new is attention to the systematic significance of self-knowledge in Plato’s philosophical economy and its role in how his thinking and his work stand together. It is this interest and attention that the volume aims to further and deepen.