Neoplatonism
From Thelemapedia
Philosophical school reputedly founded by Ammonius Saccas; chief exponents included Plotinus, Porphyry, and Iamblichus. It was a development of new ideas based on the older Platonic thought (see Plato). Speaks of the One (source of all being), of the Over-Mind (mind, spirit, intelligence; Gk. nous) which emanates from the One, and of the Over-Soul (or World-Soul; Gk. psyche), which emanates from the Over-Mind. The Over-Soul makes, produces, or generates individual souls and matter (the concrete, corporeal, or phenomenal world), which is evil. Man is part spirit, part matter; his soul is part of the World-Soul. For salvation, he/she should strive to free him/herself (as far as possible) from the body and from sin and achieve communion with the One by avoiding what is sensual (but without excessive asceticism). One can see some of this thought in the writings of Augustine of Hippo (esp. in his Confessions, Book VIII).
Some modern movements which borrow heavily from Neoplatonism are Theosophy, and the beliefs and teachings of Pierre Teilhard de Chardin.