immaterialist

An immaterialist is a philosopher who holds that reality is fundamentally mental or non-material, or that material objects do not exist independently of perception. The term is often used to describe adherents of immaterialism or idealism, emphasizing mind-dependent existence.

The best-known proponent is George Berkeley, an 18th-century Irish philosopher. Berkeley argued that what we call physical objects are collections of perceived ideas, and that there is no verifiable way to establish the existence of matter apart from perception. His dictum esse est percipi—“to be is to be perceived”—summarizes the view. For Berkeley, sensible qualities are attributes of ideas in a perceiver’s mind, and the continued existence of objects beyond immediate perception is secured by God, who perceives all things continuously.

The immaterialist position faces several criticisms, notably concerning the apparent causal efficacy of objects and the reliability of perception if objects do not exist independently of observers. Proponents respond that materialism presupposes an unperceived substance and that a coherent system of minds or God’s continuous perception can account for stable experience. Critics, including some common-sense realists and later empiricists, argue that immaterialism undermines the objective features of the external world.

In modern philosophy, immaterialism is less common as a label in analytic contexts but continues to influence debates on perception, consciousness, and the mind–matter relation. It is often discussed in relation to idealism, phenomenology, and discussions of how mental states relate to the world we experience. See also idealism, Berkeley, realism, and the philosophy of perception.