Jean-Paul Sartre was a renowned French philosopher, famed for his existentialist thoughts and contributions to 20th-century literature and philosophy.
Søren Kierkegaard was a Danish philosopher and theologian who profoundly influenced existentialism and modern psychology.
Herbert Marcuse, a German-American philosopher and sociologist, was a prominent figure in the Frankfurt School, known for his critical theory and advocacy for radical politics, influencing the New Left movement.