This thesis represents an investigation into the meaning and development of freedom in the philosophy of Martin Heidegger. Part I deals primarily with Sein und Zeit. Dasein, human reality, is defined both as a finite, thrown being-in-the-world and as a free entity, projecting its possibilities. Dasein achieves authenticity in the renunciation of the crowd and by embracing its ultimate possibility – death. The conclusion to Part I argues for the identity, in Heidegger's thought, of finite freedom and temporality. Part II deals with Gelassenheit, a work of Heidegger's latter period. Freedom is expressed in a new vocabulary. Man must release himself but the initiative in the freedom process is no longer with Dasein but with Being. The Critique, which concludes the paper, sees the latter Heidegger as an attempt to transcend the temporal horizon imposed by Kant.