This volume presents Heidegger's 1924 Marburg lectures which lay the intellectual groundwork for his magnum opus, Being and Time. Here are the seeds of the ideas that would become Heidegger's unique and highly influential phenomenology. Heidegger interprets Aristotle's Rhetoric and looks closely at the Greek notion of pathos. These lectures offer special insight into the development of his concepts of care and concern, being-at-hand, being-in-the-world, and attunement, which were later elaborated in Being and Time. Available in English for the first time, these lectures make a significant contribution to ancient philosophy, Aristotle studies, Continental philosophy, and phenomenology.