J. W. Dunne (Intrusions?, The Jumping Lions of Borneo, Serial Universe) first published his ground-breaking theory of time in 1927. Spurred by dreams and other personal experiences to an intense interest in the nature of time and human perception, Dunne designed an experiment whose purpose was to isolate the barrier dividing our knowledge of the past from that of the future. Conversant with the concepts and language of physics -- which he deemed inadequate to describe a world that is largely experiential -- Dunne weaves an intriguing, intelligent, and convincing theory that has earned him a...