immaterialism the view that objects are best characterized as mere collections of qualities: ‘a certain colour, taste, smell, figure and consistence having been observed to go together, are accounted one distinct thing, signified by the name apple’ (Berkeley, Principles, 1). So construed, immaterialism anticipates by some two hundred years a doctrine defended in the early twentieth century by Russell. The negative side of the doctrine comes in the denial of material substance or matter. Some philosophers had held that ordinary objects are individual material substances in which qualities inhere. The account is mistaken because, according to immaterialism, there is no such thing as material substance, and so qualities do not inhere in it. Immaterialism should not be confused with Berkeley’s idealism. The latter, but not the former, implies that objects and their qualities exist if and only if they are perceived. See also BERKELEY , IDEALISM, PHENOME – NALIS. G.S.P.