Martin Heidegger
Martin Heidegger (1889–1976) was a German philosopher and student of Edmund Husserl. Heidegger's contributions to phenomenonology and existentialism are disregarded by many due to his activity in the German Nazi party from 1933 to 1945.
While his political actions may not have been honorable or respected today, many of his philiophical works are valuable contributions when seperated from the man himeself. (Heidegger's support of the Nazi party even contradicted some of his own works). Heidegger objected to the idea of being called one of the existentialists, because it would put him in the same category as Albert Camus and Heidegger's former student Jean-Paul Sartre, whom he did not want to be associated with due to their French political standings. Heidegger also eventually rejected the phenomenology developed by Husserl. Heidegger gave a series of lectures on Friedrich Nietzsche, although many saw this as a perversion of Nietzsche's work used to support Nazi doctrine.
Still, many of the concepts were shared between these writers. Heidegger particularly believed in freedom of choice, and the responsibility for one's actions that naturally followed. Even under pressure, man is still capable of choice, he explains, and outside influence cannot be blamed for the actions of an individual.
Heidegger can be credited for bringing attention to the works of Søren Kierkegaard. He was also a friend of Karl Jaspers.