Historical quote about 4-D space:

“When we either apply such fancies as these, or others not less inconsistent with our innate conceptions, to space relations, we are naturally led to a geometry unlike that dealt with by common-sense geometricians. We may call the geometry to which we are thus led non-Euclidean, and it may please the fanciful to find in the cumbrous term something suggestive of scientific profundity. If we called these imaginary relations “dream -geometry,” we should be somewhat nearer the truth, for it is only in dreams that men can fancy things are and are not, at one and the same time.” Richard Proctor, 1884