any system of philosophy or mysticism which proposes to attain intercourse with god and superior spirits, and consequent superhuman knowledge, by physical processes, as by the theurgic operations of some ancient platonists, or by the chemical processes of the german fire philosophers; also, a direct, as distinguished from a revealed, knowledge of god, supposed to be attained by extraordinary illumination; especially, a direct insight into the processes of the divine mind, and the interior relations of the divine nature.