Monism

The term monism was first used by Christian Wolff in his discussions of the mind-body problem to depict both philosophers who would only acknowledge the mind (idealism or mentalism) and philosophers who only acknowledged the body (materialism). The meaning Wolff originally intended by using the term has broadened in scope through the centuries, and today applies to any doctrine or theory that claims that all things, no matter how many or of what variety, can be reduced to one unified thing in time, space, or quality. Monistic philosophers including Parmenides, Democritus, Spinoza, Berkeley, Hume, Hegel, and proponents of contemporary atomic theory. The denial of monism forces commitment to either dualism or pluralism.

Monists take different views about how many substances exist. Substantial monists, such as Spinoza, maintain that everything is part of a single substance. Attributive monists maintain that, although there may be many distinct substances, they are all attributes of one type of stuff. Other doctrines are classified as types of monism. These include neutral monism, idealism, traditional materialism, and partial monism. Traditional materialism is the variety of monism which sees that everything is based in the material and physical. Hobbes subscribed to this view. Neutral monism, a doctrine of Hume, Russell, and Mach, denies that reality is based in either the physical or the mental, but rather in one particular kind of substance that can be classified as neutral stuff. Phenomenalism, in most instances, is classified under neutral monism. Idealism is the form of monism which maintains that everything is based in the mental. The two philosophers most closely associated with idealism were Berkeley and Hegel, the latter's version bases everything in and on the World Spirit. Partial monism holds that if there are many realms of being, then there is still only one substance within one of the realms upon which everything is based. Descartes is a half-subscriber to this form of monism; he accepted this theory as far as matter was concerned, but rejected it when it was applied to the mind.

-- Internet Encylopedia of Philosophy

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