Emanation(ism) is an idea in the cosmology or cosmogony of certain religious or philosophical systems. Emanation, from the Latin 'emanare' meaning "to flow from", is the mode by which all things are derived from the First Reality, or Principle. All things are derived from the first reality or perfect God by steps of degradation to lesser degrees of the first reality or God, and at every step the emanating beings are less pure, less perfect, less divine. Emanationism is a transcendent principle from which everything is derived, and is opposed to both Creationism (wherein the universe is created by a sentient God who is separate from creation) and materialism (which posits no underlying subjective and/or ontological nature behind phenomena, being immanent).
That complex things are created in nature is not in question by Creationists (Abrahamic religions, etc.), Emanationists, Pagan mystics, nihilists and atheists; rather, the two principles that are in question are the locus for creation and whether a sentient, self-aware Absolute (‘God’) is a necessity for creation. Emanationists such as Pythagoras,Plotinus, and others argued that complex patterns in nature were a natural consequence of procession from the One (Hen, Absolute).
According to Emanationism, the Absolute, its nature and its activity must be inseparably one thing only, namely will, such that the nature and activity of the Absolute is both one and the same (again, will) and by its very nature is also its activity ‘to will’ and wills things to be or occur, thereby maintaining the center of the logical system of Emanationism. In addition, agnosis, or the lack of Subjective gnosis, is a primordial privation which must be corrected before a metaphysical "Oneing" (Plotinus) can occur. Through this process, the transcendent yet immanent will of individuals is made self-reflexive by recollecting back further and further. Eventually it will reach that nature, the Noetic (and real) self, which is antecedent to the phenomenal, corporeal self. The ontologically transcendent yet immanent Self is seen as being one's unactualized nature, and this nature will remain unactualized until contemplation is brought to fruition, thereby bringing into actuality what had been merely potential.
The primary classical exponent of Emanationism was Plotinus, wherein his work, the Enneads, all things phenomenal and otherwise were an emanation from the One (Hen). In Ennead 5.1.6, Emanationism is compared to a diffusion from the One, of which there are three primary hypostases, the One (hen), the Intellect/will (nous), and the Soul (psyche tou pantos). For Plotinus, emanation, or the "soul's descent", is a result of the Indefinite Dyad, the primordial agnosis inherent to and within the Absolute, the Godhead.
Plotinus in particular argued that there is no knowledge or sentience in the Absolute, and that all things noetic and corporeal were as well a logos or proportional phenomena of the emanation of and by the One. In Plotinian Emanationism, there are lesser and lesser potencies of will as procession occurs beginning from the One, through the noetic, or the soul, finally ending in base matter, which is generally seen as utter privation.