Although no set of principles can apply uniformly to all existentialists, certain basic characteristics of existentialism are central to both the nonreligious writers like Sartre and Camus and the theistic existentialists like Kierkegaard, Maritain, Marcel, Tillich, Berdyaev, and Buber. These characteristics are (1) an insistence that human life is understandable only in terms of an individual man's existence, i.e., that man's existence precedes his essence, (2) a conviction that human reason is impotent to deal with the "dark places in human life which are 'non-reason'," (3) a feeling that modern man lives his life alienated from God, nature, other men, and his own true self, (4) a recognition of the anxiety that oppresses man because he must accept full responsibility for his own moral choices, (5) a sense that a man alienated from God and man can encounter only Nothingness, and (6) a concern to enlarge the range of human freedom. (JS)