Columbia subject headings:
Good and evil.
Ontology.
Perry, Ralph Barton, 1876-1957.
Thomas, Aquinas, Saint, 1225?-1274.
Values.
Harvard subject headings:
Good and evil
Ontology.
Perry, Ralph Barton, 1876-
Thomas, Aquinas, Saint, 1225?-1274
Values
Princeton subject headings:
Good and evil.
Ontology.
Perry, Ralph Barton, 1876-
Thomas, Aquinas, Saint, 1225?-1274.
Values.