What is Emanation?
Religious thinkers and philosophers have usually maintained that emanation has neither beginning nor end in time. It originates in a perfect and transcendent source that is not diminished by the process. The things emanated are less perfect than the source. The process of emanation is often likened to the giving off of light or heat by a fire.
In religious thought, the Gnostics used emanationist notions to describe the origin of their fantastic hierarchies of beings. Some Christians spoke of the Trinity (God the Father, God the Son, and God the Holy Spirit) in emanationist terms. It is in Neoplatonic philosophy, however, that the idea reaches its most sophisticated form. Plotinus, the greatest Neoplatonist, held that the transcendent One in its perfection spontaneously overflows, giving rise to Intellect. From Intellect emanates Soul, and so on down to matter, the lowest level of reality. Moreover, each level aspires to turn back to its source, the One. Plotinus sometimes criticized emanationism and was always aware of the inadequacy of sense imagery to describe spiritual reality. His successors were not so cautious. One, Proclus, gives the most systematic exposition of the doctrine in his Elements of Theology.
In ancient and medieval thought emanationism competed with creationism, which denies that the things created are made from the substance of the creator. In modern thought emanationism has been largely replaced by the idea of evolution, which denies a transcendent source and affirms the increasing perfection of the outcome of the process.