J ean-Paul Sartre's most influential existentialist work, Being and Nothingness , broken down into its most fertile ideas In To Freedom Condemned , Sartre's most influential work, Being and Nothingness , is laid bare, presenting the philosopher's key ideas regarding existentialism. Covering the philosophers Hegel, Heidegger, and Husserl, and mulling over such topics as love, God, death, and freedom, To Freedom Condemned goes on to consider Sartre's treatment of the complexities around human existence.