Since the publication of Sein und Zeit in 1927, scholars have coupled Martin Heidegger’s reflections on authenticity with a rich tradition of thought which reminds us that philosophy can, from time to time, function as a catalyst for self-discovery. While this function is an undeniable feature of Heideggerian authenticity, I would like to suggest that it is secondary to the role that authenticity plays in Heidegger’s philosophical investigations. By analyzing the full phenomena of authenticity and tracing its first technical uses (...) back to Heidegger’s early lectures on Aristotle, I show that Heidegger’s methodological breakthrough in the early 1920s, the development of hermeneutic phenomenology, and the very structure of Being and Time are the result of Heidegger’s appropriation of Aristotle’s philosophical method. By analyzing these lectures and traditionally ignored uses of authenticity in Being and Time, I develop an account of the methodological sense of authenticity which looks to the tradition to uncover phenomena which have been obscured and covered over. In comparing this methodological reading to some standard readings, what I call the existential, intentional, and practical readings of authenticity, I show that the problems which arise in these accounts can be addressed by considering the full phenomena of authenticity and its methodological role in Heidegger’s thinking. Ultimately, I show that the term “authenticity [Eigentlichkeit]” is not only an ineliminable part of the structure of Heidegger’s Being and Time but that it is also at the heart of his phenomenological method. (shrink)