Hölderlin's hymn "The Ister"

Martin Heidegger (26 September 1889 – 26 May 1976) was a German philosopher whose work was central to the development of phenomenology, hermeneutics, and existentialism. He has had significant impact within subsequent philosophy, social sciences and humanities, and theology. Heidegger's magnum opus, Being and Time (1927), is widely considered one of the most significant works of modern philosophy. In it, he introduced the concept of Dasein ("being-there") to describe the distinctive character of human existence, arguing that humans possess a "pre-ontological" understanding of being that shapes how they live and act, which he analyzed in terms of the unitary structure of "being-in-the-world". Through his analysis of Dasein, Heidegger sought to reawaken what he called "the question of being": the fundamental inquiry into what makes entities intelligible as the entities they are.