The Collaborative International Dictionary
Monopsychism
Monopsychism \Mon`o*psy"chism\, n. [Mono- + Gr. ? soul.] The doctrine that there is but one immortal soul or intellect with which all men are endowed.
Wiktionary
monopsychism
n. The doctrine that there is only one immortal soul or intellect with which all human beings are endowed.
Wikipedia
Monopsychism
Monopsychism is the belief that all humans share the same eternal consciousness, soul, mind and intellect. It is also a recurring feature in many mystical traditions.
Monopsychism is a doctrine of Sabianism, Jewish Kabbalah, and Averroism, and also forms a part of the Rastafarian belief system.