I
In metaphysics , the doctrine opposed to monism .
Whereas monists such as Parmenides , Benedict de Spinoza , and G.W.F. Hegel maintain that reality consists of only one ultimate substance, pluralists assert that reality consists of manifold entities of many different types and that the diversity of things is more striking and important than their unity. In A Pluralistic Universe (1909), William James held that it is characteristic of empirically minded thinkers to note the changeability of things, the multiplicity of their being and their relations with one another, and the unfinished character of the world.
II
In political science, the view that in liberal democracies power is (or should be) dispersed among a variety of economic and ideological pressure groups and is not (or should not be) held by a single elite or group of elites.
Pluralism assumes that diversity is beneficial to society and that the disparate functional or cultural groups of which society is composed
including religious groups, trade unions, professional organizations, and ethnic minorities
should be autonomous. Pluralism was stressed most vigorously during the early 20th century by a group of English writers that included Frederic W. Maitland and Harold J. Laski ; it was defended in the later 20th century by the American scholars Robert Dahl and David B. Truman.