a fundamental category of existentialism. According to the 19th-century philosopher Søren Kierkegaard (Kierkegaard, Søren), dread, or angst, is a desire for what one fears and is central to his conception of original sin. For the 20th-century German philosopher Martin Heidegger (Heidegger, Martin), anxiety is one of the distinctive ways through which Dasein (the historical person) is disclosed as a contingent being, and thus anxiety is that through which fear first becomes possible.