Martin Heidegger (1889-1976) was a German philosopher known for his existential and phenomenological approach. He is considered one of the most influential philosophers of the 20th century, with his work exploring themes such as Being, time, and the nature of existence. Heidegger's concept of Dasein, or 'being-there,' played a significant role in shaping modern philosophy and existentialism. Despite controversy surrounding his involvement with the Nazi Party, Heidegger's works continue to be studied and debated in academic circles worldwide.