Volume 18 of Martin Heidegger's collected works presents his important 1924 Marburg lectures which anticipate much of the revolutionary thinking that he subsequently articulated in Being and Time. Here are the seeds of the ideas that would become Heidegger's unique 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, they make a significant contribution to ancient philosophy, Aristotle studies, Continental philosophy, and phenomenology.