Plotinos: Complete Works, v. 3 In Chronological Order,...

12. We therefore repeat that since we admit that our universe is modeled on the intelligible World, we should so much the more recognize that the latter is the universal living Organism, which constitutes all things because it consists of perfect essence. Consequently in the intelligible world, the heavens also are an animated being, not even lacking what here below are called the stars; indeed the latter are what constitutes the heavens' essence. Neither is the Earth on high something dead; for it is alive, containing all the Animals that walk on the ground, and that are named terrestrial, as well as Vegetation whose foundation is life. On high exist also the Sea and the Water in universal condition, in permanent fluidity and animation, containing all the Animals that dwell in the water. Air also forms part of the intelligible world, with the Animals that inhabit the air, and which on high possess a nature in harmony with it. How indeed could the things contained in a living being not also themselves be living beings? Consequently they are also such here below. Why indeed should not all the animals necessarily exist in the intelligible World? The nature of the great parts of this world indeed necessarily determines the nature of the animals that these parts contain. Thus from the "having" and "being" (existence and nature) of the intelligible world is derived that of all the beings contained therein. These things imply each other.

To ask the reason for the existence of the Animals contained in the intelligible world, is to ask why exists this very world itself, or the universal living Organism, or, what amounts to the same thing, why exist the universal Life, the universal Soul, in which are found no fault, no imperfection, and from which everywhere overflows the fulness of life.