A prolific playwright, poet, editor, and essayist, Clifford Bax considered himself an "ardent theosophist" at the age of twenty-three. His life-long interest in the metaphysical is the basis for the common philosophical thread in much of his variegated output. Although Bax achieved modest success as a playwright, the subtle amalgam of Platonic, Christian, and Buddhist though developed in his essays seems sharply out of sympathy with the rationalistic materialism of his time. When working in an autobiographical mode, as in Inland Far: A Book of Thoughts and Impressions (1925), Bax conveys with admirable detachment his commitment to spiritualism. His impressionistic method is less suited to his biographical works, however, such as those on Leonardo da Vinci (1932) and Nell Gwyn (1932), which have, as a result, been less appreciated by reviewers. Also less successful is the more argumentative tone of That Immortal Sea: A Meditation upon the Future of Religion and...