Columbia subject headings:
Feuerbach, Ludwig, 1804-1872.
Marx, Karl, 1818-1883.
Metaphysics--History.
Nietzsche, Friedrich Wilhelm, 1844-1900.
Philosophy, Modern.
Harvard subject headings:
Feuerbach, Ludwig, 1804-1872--Criticism and interpretation.
Marx, Karl, 1818-1883--Criticism and interpretation.
Nietzsche, Friedrich Wilhelm, 1844-1900--Views on Western civilization.
Princeton subject headings: