A broad-reaching and ambitious cultural and intellectual history, The Emergence of the Fourth Dimension describes the development and proliferation of the idea of higher dimensional space in the late nineteenth- and early twentieth-centuries. Featuring figures as diverse as the Cambridge Platonist Henry More, the German psychologist Hermann von Helmholtz, the ever-popular work of H.G. Wells, and a series of spiritualists and occultists, it describes a body of thought that finds in the fourth dimension a Neverland of fantastic imaginative possibility. Describing the contortion of this already giddying notion into yet more peculiar imaginative forms, and the growing sense of excitement that accompanied them, The Emergence of the Fourth Dimension gives a glimpse of what it was like, in the nineteenth century, to think in 4D.