Existentialism was one of the leading philosophical movements of the twentieth century and had more impact on literature and the arts than any other school of thought. Focusing on the leading figures of existentialism, including Sartre, Nietzsche, Heidegger, Kierkegaard, de Beauvoir, Merleau-Ponty, and Camus, Thomas Flynn offers a concise account of existentialism, explaining the key themes of individuality, free will, and personal responsibility, which marked the movement as a way of life, not just a way of thinking.