n. Division into two; a twofold division; duality.n. In philosophy, in general, that way of thinking which seeks to explain all sorts of phenomena by the assumption of two radically independent and absolute elements, without any continuous gradation between them: opposed to monism.n. To the doctrine of a double absolute, especially a principle of good and a principle of evil, or a male and a female principle.n. In theol.: The doctrine that there are two independent divine beings or eternal principles, one good and the other evil: characteristic especially of Parsism and various Gnostic systems.n. The heretical doctrine, attributed to Nestorius by his opponents, of the twofold personality of Christ, the divine logos dwelling as a separate and distinct person in the man Christ Jesus, and the union of the two natures being somewhat analogous to the indwelling of the Holy Spirit in the believer; that view of the personality of Christ which regards him as consisting of two personalities.n. In chem., a theory advanced by Berzelius which assumed that every compound, whether simple or complex, must be constituted of two parts of which one is positively and the other negatively electrified.n. In general, any system or theory involving a duality of principles