In 1980, Michel Foucault began a vast project of research on the relationship between subjectivity and truth, an examination of conscience, confession, and truth-telling that would become a crucial feature of his life-long work on the relationship between knowledge, power, and the self. The lectures published here offer one of the clearest pathways into this project, contrasting Greco-Roman techniques of the self with those of early Christian monastic culture in order to uncover, in the latter, the historical origin of many of the features that still characterize the modern subject. They are accompanied by a public discussion and debate as well as by an interview with Michael Bess, all of which took place at the University of California, Berkeley, where Foucault delivered an earlier and slightly different version of these lectures. Foucault analyzes the practices of self-examination and confession in Greco-Roman antiquity and in the first centuries of Christianity in order to highlight a radical transformation from the ancient Delphic principle of "know thyself" to the monastic precept of "confess all of your thoughts to your spiritual guide."0.