An exploration of the 20th Century Philosophy which claimed that ‘existence preceded essence’, or, in effect, that men and women define their own being through their acts and choices. After an Introduction examining the historical moment of Existentialism, as a product of wartime discipline and consciousness, this book sets out the thinking of Kierkegaard and Nietzsche, Jean-Paul Sartre, Simone de Beauvoir, Martin Heidegger and Karl Jaspers on the broad questions of What is Man?’; ‘What Can I Know?’ and ‘What must I do?’ It introduces models of Abandonment, The Absurd and Ambiguity; Consciousness and Freedom; Being-in-itself and Being-for-itself, Bad Faith, Facticity and Possibility, Dasein, or there-being, Temporality, attitudes towards Death; The Will-to-Power, The Superman, and the so-called Kingdom of Ends. The book glances throughout at literary contributions to Existentialism, and ends with brief biographies of the major Existentialists and an extensive glossary of terms.