1. Fritz Kaufmann, The World as Will and Representation (Boston: Beacon Press, 1957), p. vii.
2. Kaufmann, “Art and Religion” in Philosophy and Phenomenological Research, vol. 1, No. 4, June 1941, p. 463.
3. Kaufmann, “On Imagination” in Philosophy and Phenomenological Research, vol. 7, no. 3, March, 1947, p. 372.
4. Martin Heidegger, “Hölderlin and the Essence of Poetry” in Existence and Being (Chicago: Henry Regnery, 1949), p. 281.
5. Maurice Natanson, “The Empirical and Transcendental Ego” in For Roman Ingarden; Nine Essays in Phenomenology, ed, Anna-Teresa Tymieniecka (Gravenhage: Nijhoff, 1959), p. 43.