Materialism is a form of philosophical monism which holds that matter is the fundamental substance in nature, and that all phenomena, including mental phenomena and consciousness, are identical with material interactions.

Materialism is closely related to physicalism, the view that all that exists is ultimately physical. Philosophical physicalism has evolved from materialism with the discoveries of the physical sciences to incorporate more sophisticated notions of physicality than mere ordinary matter, such as: spacetime, physical energies and forces, dark matter, and so on. Thus the term "physicalism" is preferred over "materialism" by some, while others use the terms as if they are synonymous.

Philosophies contradictory to materialism or physicalism include idealism, pluralism, dualism, and other forms of monism.

Overview

Materialism belongs to the class of monist ontology. As such, it is different from ontological theories based on dualism or pluralism. For singular explanations of the phenomenal reality, materialism would be in contrast to idealism, neutral monism, and spiritualism.

Materialism or materialist may refer to: