This is a brilliant, incredibly learned book about a highly esoteric and complex subject. In this book Izutsu presents not only a lucid and highly erudite analysis of both Sufism and Taoism, but he also makes a compelling case for the high degree of confluence between the thoughts and spiritual insights of Ibn Al Arabi and Lao Tsu's mystical visions. Highly recommended for anyone with the philosophical background and attention span to read and re-read the book carefully enough to follow its argument.