When Linda Dalrymple Henderson's The Fourth Dimension and Non-Euclidean Geometry in Modern Art first appeared in 1983 it generated a lively discussion, most conspicuously in the pages of the journal Leonardo. Here was a book that undermined two of the central tenets of modernist theory: first that developments in art and science were linked not by any real connections or strong form of shared endeavour but by the fact that both partook of the modern spirit or zeitgeist; second, and more specifically, that Einsteinian relativity and cubism were in some way analogous embodiments of that spirit. By relentlessly pursuing the fate of two nineteenth-century developments – the non-Euclidean geometries and higher dimensions of her title – Henderson clearly showed that many of the avant-garde artworks so admired by critics for their formal innovation were at once more literal and more bizarre than anyone had previously suspected. Some were attempts to expound the ‘geometrical occult’ or to engage in multidimensional communion, some projected the enhanced intellect of ‘four-dimensional man’ and others explored the lonely but profound reaches of hyperspace. As she puts it in the ‘Re-introduction’ to this new edition of The Fourth Dimension, ‘these works function as “windows” on an invisible meta-reality of higher dimensions and etherial energies' (p. 27), and, elsewhere, ‘belief in a fourth dimension encouraged artists to depart from visual reality and to reject completely the one-point perspective system that for centuries had portrayed the world as three-dimensional’ (p. 492).