(Neoplatonic) emanationist cosmology rests on the tenet—based to some extent in observation, but elevated by them to the status of a heuristic principle—that every activity in the world is in some sense double insofar as it possesses both an inner and an outer aspect. For example, the inner activity of the sun (nuclear fusion, as we now know) has the outer effect of heat and light, themselves activities as well. Or the inner activity of a tree that is determined by the kind of tree it is (its genetic code, we would now say; the Neoplatonists spoke of an inherent formative principle, logos) results in the bearing of a particular kind of fruit; or again, thoughts and feelings internal to human beings express themselves in speech and actions. In each case, the outer effect is not the purpose or end of the inner activity; rather, it is simply the case that one falls out of the other and is concomitant with it. Furthermore, it is also the case that these outer activities will typically be productive of yet other outer activities that are ontologically more remote and derivative: Fruit serves as nourishment or poison for other individual life forms, and human speech and action constitute, over time, a person’s biography or a society’s history. It is important to note that, in all cases, the outer activity will not be some random affair, but rather something intimately connected with the inner activity it is an expression of. In other words, any inner activity will somehow prefigure the character and nature of its outer effect. Thus, the Neoplatonists insisted that there is nothing on the lower ontological levels within the chains of causality that is not somehow prefigured on the corresponding higher levels. In general, no property emerges unless it is already in some way preformed and pre-existent in its cause.
Christian Wildberg, ‘Neoplatonism,’ Stanford Encyclopedia of Philosophy