Monism

1. (Metaph.) That doctrine which refers all phenomena to a single ultimate constituent or agent; -- the opposite of dualism.
2. (Biol.) See Monogenesis, 1.
3. The doctrine that the universe is an organized unitary being or total self-inclusive structure.

The doctrine has been held in three generic forms: matter and its phenomena have been explained as a modification of mind, involving an idealistic monism; or mind has been explained by and resolved into matter, giving a materialistic monism; or, thirdly, matter, mind, and their phenomena have been held to be manifestations or modifications of some one substance, like the substance of Spinoza, or a supposed unknown something of some evolutionists, which is capable of an objective and subjective aspect.