Of these, the former endeavours to explain the most elaborate psychical activities of men as developments of elementary forms of conscious processes in the animal kingdom as a whole; the latter is a defence of the theory of natural selection against the attacks of St George Mivart, and appeared in an English edition on the suggestion of Darwin.
Lord Rayleigh had an interest in abnormal psychological investigations, and became a member and vicepresident of the Society for Psychical Research.
Further arguments in the same direction are derived from the modern school of psychical research (see especially F.
Materia, matter), in philosophy, the theory which regards all the facts of the universe as explainable in terms of matter and motion, and in particular explains all psychical processes by physical and chemical changes in the nervous system.
2 See the articles on Psychical Research; Magic; Conjuring; Automatism; Divination; Crystal Gazing; Hypnotism; Apparitions; Hallucinations; Hauntings, &C.