Monism

Monism is a philosophy and a metaphysical stance that everything in the universe is originally comprised of one thing or is controlled by one principle.

Variations
Monism had many variations during Ancient Greece:
 * Thales believed that everything had originated from water.
 * Anaximander believed that everything had originated from Apeiron, which is existent, indefinent and eternal.
 * Anaximenes believed that everything had originated from air.
 * Heraclitus believed that everything had originated from fire, which also means the 'change'.

Monism had later influenced Pythagoreanism, which believed that everything is a manifestation of mathematics. Monism had also later expanded to theory of classical elements, which refers to fire, water, soil, air.

In short, Monism largely influenced not only philosophy but also mathematics, physics, chemistry and science in general. The question on the source of everything in universe is still unanswered as wether what is comprising elementry particles is unknown.

Types

 * Metaphysical Monism (also known as Existence Monism)
 * Metaphysical monism posits that, strictly speaking, there exists only a single thing, the universe, which can only be artificially and arbitrarily divided into many things.
 * Substance Monism
 * Substance monism posits that only one kind of substance exists, although many things may be made up of this substance, e.g., matter or mind.
 * Priority Monism
 * Priority monism states that all existing things go back to a source that is distinct from them; e.g., in [[File:Neoplaton.png]] Neoplatonism everything is derived from The One. In this view only the One is ontologically basic or prior to everything else.
 * Dual-aspect monism
 * Dual-aspect monism is the view that the mental and the physical are two aspects of, or perspectives on, the same substance.
 * Neutral monism
 * Neutral monism believes the fundamental nature of reality to be neither mental nor physical; in other words it is "neutral".