Jean-Paul Charles Aymard Sartre (June 1905 – April 1980) is arguably the best known philosopher of the twentieth century. His indefatigable pursuit of philosophical reflection, literary creativity and, in the second half of his life, active political commitment gained him worldwide renown, if not admiration. He is commonly considered the father of Existentialist philosophy, whose writings set the tone for intellectual life in the decade immediately following the Second World War.
– plato.stanford.edu