What is the task of philosophy, asks the young Heidegger while still resounds the echo of the mortars of the First World War. What is new in its dialogue with philosophers of the stature of Dilthey, Rickert, Natorp and Husserl? In other words, your attitude against hermeneutics, psychologist, Kantianism or phenomenology? Here is some of the key issues raised in these first lessons of Heidegger, as he begins his promising academic career at the University of Freiburg (1919 - 923) as an assistant to Husserl.