This thesis offers a genealogical-exegetical account of Heidegger’s phenomenology of mood (Stimmung), focusing on his Freiburg and Marburg lectures from 1919 to 1925. In Being and Time, moods manifest the transcendental factical ground of “thrownness” (Geworfenheit) in which an understanding of Being is constituted. However, throughout Heidegger’s work, moods have operated as the ground for disclosure, the origin of authentic ontological understanding, the defining character of each historical epoch and as the enactmental urgency that will bring about an ‘other’ beginning. This thesis contextualizes Heidegger’s accounts of mood within the broader phenomenological project concerning the constitution and grounding of meaning. The first part ...