The document provides an overview of existentialism through notes from a philosophy class. It defines existentialism and outlines its key themes, including the view that existence precedes essence, the absurdity of life, alienation, nothingness and death, anxiety, and human freedom. The document also profiles influential existentialist philosophers like Kierkegaard, Nietzsche, Camus, and Sartre. Kierkegaard believed individuals must live authentically through personal choice and commitment rather than conforming to social norms. Nietzsche saw life as meaningless and advocated becoming an "overman" who can overcome desires to live independently and reinvent oneself.