Jean-Paul Sartre (1905 - 1980) was a French philosopher and writer awarded the 1964 Nobel Prize in Literature which he refused. Sartre is commonly considered one of the best known philosophers of the 20th century due to his development of Existentialist philosophy, postulating an idea that existence precedes essence. Sartre wrote that the most important consideration for a man is that he first of all exists, being independently acting and responsible for his actions. The actual life of a man is what constitutes his "true essence" instead of labels, roles and stereotypes that others attribute to him.