Interest in dream and madness, conceived as the loss of a world shared with others, and the individual’s entry into a private world governed by a personal logic unrelated to the waking state and to common feeling, recurs in at least three of Kant’s works: Essay on the Diseases of the Head, (1764), Dreams of a Spirit-Seer (1766), and Anthropology from a Pragmatic Point of View (1798). Hegel too,...