Columbia subject headings:
Hartshorne, Charles, 1897-2000.
Metaphysics.
Whitehead, Alfred North, 1861-1947.
Harvard subject headings:
Hartshorne, Charles, 1897-2000
Hartshorne, Charles, 1897-2000--Metaphysics.
Metaphysics
Whitehead, Alfred North, 1861-1947
Whitehead, Alfred North, 1861-1947--Metaphysics.
Princeton subject headings:
Hartshorne, Charles, 1897---Metaphysics.
Metaphysics.
Whitehead, Alfred North, 1861-1947--Metaphysics.