The Moral Philosophy of Santayana, Columbia University Press. 1939.
Space, Time and Creation, The Free Press. 1957.
The Mystery of Existence: An Essay in Philosophical Cosmology, Appleton Century-Crofts, 1965.
Existence and Logic, New York University Press, 1974.
The Ways of Philosophy, Macmillan Publishing Company, 1979.
Contemporary Analytic Philosophy, Macmillan Publishing Company, 1981.
Cosmic Understanding: Philosophy and Science of the Universe, Princeton University Press, 1986.
The Question of Reality, Princeton University Press, 1990.
Does Life Have a Meaning?, Prometheus Books, 1993.
One Universe or Many, Journal of the History of Ideas, Vol. XII, No. 2, April, 1951.
Kantian Dialectic and Modern Scientific Cosmology, The Journal of Philosophy, Vol. 48, No.10, May 10, 1951.
Ideals and Essences in Santayana’s Philosophy, in The Philosophy of George Santayana, Vol. II, The Library of Living Philosophers.
Scientific Method in Cosmology, Philosophy of Science, Vol. 19, No. 2, April, 1952.
Creation and the “New” Cosmology, The British Journal for the Philosophy of Science, Vol. V, No. 17, 1954.
On the Use of ‘Universe’ in Cosmology, The Monist, Vol. 48, No. 2, April, 1964.
The Concept of the World, in Munitz, Milton K. and Howard Kiefer, editors, Language, Belief and Metaphysics, State University of New York Press, 1970.
Approaches To Existence, Philosophy East and West, Vol. XXV, No. 3, July, 1975.
(Including only those in which there are substantial introductions and/or commentary)
Theories of the Universe: From Babylonian Myth to Modern Science, The Free Press, 1957.
A Modern Introduction to Ethics: Readings from Classical and Contemporary Sources, The Free Press, 1958.
Introduction to Kant, Immanuel, Universal Natural History and Theory of the Heavens, The University of Michigan Press, 1969.
Identity and Individuation, New York University Press, 1971.
Logic and Ontology, New York University Press, 1973.