monism
Pronunciation: /ˈmɒnɪz(ə)m, ˈməʊ-/
noun
Philosophy & Theology- a theory or doctrine that denies the existence of a distinction or duality in a particular sphere, such as that between matter and mind, or God and the world.
- the doctrine that only one supreme being exists. Compare with pluralism.

Origin:
mid 19th century: from modern Latin monismus, from Greek monos 'single'