monism

Philosophy, in metaphysics, any of various theories holding that there is only one basic substance or principle as the ground of reality, or that reality consists of a single element. In epistemology, a theory that the object and datum of cognition are identical. Monism is in contrast to dualism and pluralism.

Source: monism. Dictionary.com. Dictionary.com Unabridged (v 1.1). Random House, Inc. http://dictionary.reference.com/browse/monism (accessed: February 18, 2007).