What is "heteroousianism"

Heteroousianism (or heterousianism) is a Christian belief that the substance or being of God the Father and the substance or being of the Son of God ( Jesus) are different. Commonly called Arianism, though Arianism includes other beliefs in addition to this one. The teaching was developed as a response to the homoousian teaching.

The term derives from the Greek , heterooúsios, "differing in substance" from , héteros, "another" and , ousía, "substance, being".

The hardline form of heteroousianism, in which the substance of the Father and Son are not only said to be different, but also dissimilar, is usually called Anomoeanism.