Eduard von Hartmann (1842-1906) had expected to follow his father's military career, but an injury forced him to reassess his ambitions. Torn between music and philosophy, he settled on the latter and in 1869 published his first book, The Philosophy of the Unconscious, which proved a great success. Published in 1885 as the period saw an enormous rise in the popularity of spiritualism, this work attempts to give psychological explanations for all occult phenomena, including subjective delusions as well as 'objective' physical manifestations, without resorting to hypotheses of ghosts, demons or trickery. C. C. Massey, a leading theosophist and translator of the work, wrote, 'Now for the first time, a man of commanding intellectual position has dealt fairly by us as an opponent.' This work will appeal to anyone with an interest in the growth of spiritualism and the philosophical and metaphysical debates of the nineteenth century.