In the next place, let us show whence they derive the whole of this number. It is necessary therefore, that they should have their hypostasis from the Gods prior to them; since the progression to the assimilative Gods was from the intellectual fathers, and to the intellectual fathers supernally from the intelligible and at the same time intellectual Gods, just as to these the progression was from the first intelligibles. For since the order of the assimilative rulers is prior to that of the liberated Gods; as is also the triad of the intellectual kings; or rather the demiurgic monad establishing in itself the all-perfect measure of the division of wholes into the triad,--this being the case we must survey the causes of the generation of the liberated Gods according to both these, viz. according to the demiurgic measure, and the genera of the assimilative Gods. For the different orders of them are imparted from these two.
Moreover, if we remember what has been before observed, we gave a fourfold division to the middle progressions of the assimilative Gods. And we said, that some of them are paternal, others prolific, others of an elevating, and others of a guardian nature. Since therefore, the demiurgic monad divides progressions into first, middle, and last, in the same manner as the intelligible father prior to it, but the Gods posterior to this monad, emit the rivers of themselves tetradically to secondary natures,--this being the case, the dodecad of liberated Gods presents itself to our view, above indeed proceeding according to the triad, but beneath being quadruply multiplied. Hence, of the genera which give completion to it; some indeed, are allotted the demiurgic and paternal triadically; others, the generative and vivific triadically; others, the elevating peculiarity triadically; and others after the same manner the undefiled and guardian characteristic. For all their peculiarities are derived from the multitude of the assimilative Gods. But the division of them into first, middle and last, proceeds from the demiurgic cause. And thus much concerning the number of the liberated Gods, whence, and how it is generated.
The Six Books of Proclus, the Platonic Successor, on the Theology of Plato (vol. 2 of 2) · The Wunder Library — complete classics, free to read, with narration.