The persistent problems of philosophy : an introduction to metaphysics through the study of modern systems, by Mary Whiton Calkins ... Calkins, Mary Whiton, 1863-1930. Philosophy, Modern History. Metaphysics. B791 .C2 1925 110 CAP Contains bibliographies. New York, The Macmillan Company, 1925. 1925. 1925 Text xxvi, 601 p. eng