The writer acknowledged for their contributions to existential philosophy is Jean-Paul Sartre. As a key figure in the existentialist movement, Sartre explored themes of freedom, absurdity, and the human condition in his works. His publications, including "Being and Nothingness," challenge readers to contemplate the meaning and responsibility of individual existence. Sartre famously declared, "existence precedes essence," emphasizing that people create their own purpose. His profound influence extended beyond literature to impact politics and ethics, positioning him as one of the most significant philosophers of the 20th century.