Martin Heidegger (; German: [ˈmaʁtiːn ˈhaɪdɛɡɐ]; 26 September 1889 – 26 May 1976) was a key German philosopher of the 20th century. He is best known for contributions to phenomenology, hermeneutics, and existentialism. Heidegger was a member and supporter of the Nazi Party. There is controversy as to the relationship between his philosophy and his Nazism.