Columbia subject headings:
Nietzsche, Friedrich Wilhelm, 1844-1900.
Schopenhauer, Arthur, 1788-1860.
Harvard subject headings:
Schopenhauer, Arthur, 1788-1860--Criticism and interpretation.
Schopenhauer, Arthur, 1788-1860--Ethics.
Princeton subject headings:
Essays.
Nietzsche, Friedrich Wilhelm, 1844-1900.
Schopenhauer, Arthur, 1788-1860.