Martin Heidegger (26 September 1889 – 26 May 1976) was a German philosopher and a seminal thinker in the Continental tradition of philosophy. He is «widely acknowledged to be one of the most original and important philosophers of the 20th century.» Heidegger is best known for his contributions to phenomenology, hermeneutics, and existentialism, though as the Stanford Encyclopedia of Philosophy cautions, «his thinking should be identified as part of such philosophical movements only with extreme care and qualification». Heidegger was a member and public supporter of the Nazi Party. There is controversy over the degree to which his Nazi affiliations influenced his philosophy. His first and best known book, Being and Time (1927) is one of the central philosophical works of the 20th century.