The genius of May Sinclair lies in her brilliant bridging of the Victorian and the modern eras, in her determination never to become ossified in an outdated way of thought or of Art. Though a generation older than the famous literati of the postwar era, she clearly perceived what was worth saving of the old and what was worth embracing of the new. This is clear, of course, in her remarkable fiction, particularly in the astonishing “Life and Death of Harriet Frean,” “Mary Olivier,” and “Tree of Heaven,” in which she broke new ground in psychological and stream-of-consciousness fiction. It is also true, however, in her crystal-clear philosophical works, “In Defense of Idealism” and “The New Idealism.” Though philosophical Idealism had become passé to many in the new era of scientific and mathematical Realism, Sinclair saw an opportunity to transmute her beloved, hard-won philosophy into a new kind of Idealism, one which absorbed the valuable insights of realists such as Einstein, Samuel Alexander, Alfred North Whitehead, and Bertrand Russell rather than rejecting them, producing a keen-eyed new view of transcendence and mystical meaning in the Universe.