(Latin: spiro, breathe)
(1) The theory that the living can, and do communicate with the spirits of the departed, which claims to prove the preamble of all religion, and to establish or disprove by its methods the essential truths of Cbristianity.
(2) The name given to the various practises by which such communication is attempted. Its phenomena are physical (raps, movements of tables, apparitions, etc.) and psychical (expressing ideas or containing messages), and its alleged results are often deceptive and farcical.