Abstract
This paper attempts to exhibit the young Heidegger’s academic and personal thinking path which stems from the two university dissertations (1913 and 1915 respectively) and ends up leading to his first lecture at the University of Freiburg on the determination of philosophy (1919). It is purported in the first place to render an account of the personal circumstances that convinced Heidegger of modifying his own early purposes of becoming a priest, then a theologian and finally a confessional Catholic philosopher by means of an examination of the philosophical themes which motivate his early work (Neokantianism, medieval speculative grammar and Husserlian phenomenology). In the second place, an attempt is made in order to consider Heidegger’s first Freiburg lecture in which the young philosopher intends the enterprise of undermining the primacy of the theoretical and in which he launches a series of remarkable objections (of hermeneutical nature) against Husserlian phenomenology.