Existentialism, as a philosophy, gained prominence after World War II. Instead of focusing upon a particular aspect of human existence, existentialists argued that our focus must be upon the whole being as he/she exists in the world. Rebelling against the rationalism of such philosophers as Descartes and Hegel, existentialists reject the emphasis placed on man as primarily a thinking being. Freedom is central to human existence, and human relations and encounters cannot be reduced simply to "thinking. " This Dictionary provides--through alphabetically arranged entries--overviews of the various tenets, philosophers, and writers of existentialism, and of those writers/philosophers who, in retrospect, seem to existentialists to espouse their philosophy: Nietzsche, Kierkegaard, Dostoyevski, et al.