: a theory that considers reality to consist of two irreducible elements or modes (as mind and matter)
: a theory in hematology holding that the blood cells arise from two kinds of stem cells one of which yields lymphatic elements and the other myeloid elements
In philosophy, any pair of irreducible, mutually heterogeneous principles used to analyze the nature and origins of knowledge (epistemological dualism) or to explain all of reality or some broad aspect of it (metaphysical dualism); also, any theory that employs dualisms. Examples of epistemological dualisms are subject and object and sensation and sensibilia; examples of metaphysical dualisms are mind and matter, good and evil, and God and world. Dualism is distinguished from monism and pluralism.