In 1875, the geophysicist Balfour Stewart and the mathematician P. G. Tait published the second edition of The Unseen Universe. The book's aim had been 'to overthrow materialism by a purely scientific argument', and its initial success, and the controversy it aroused, prompted this revised edition. The treatise suggests that science and religion could be reconciled, and that by using science, it could be proved that the soul survives after death. The book begins with a historical account of the beliefs about the afterlife of ancient Egypt, the Greeks, Buddhism and Christianity. The authors then refine a Ptolemaic vision of the universe in which the material universe is surrounded by concentric, invisible universes. The Unseen Universe discusses the nature of matter and ether, Newton's laws, and the idea that, through electromagnetism, the soul upon death transfers molecularly from the visible to the invisible universe.