The Six Books of Proclus on the Theology of Plato, Volume 2

Every thing divine is itself indeed, on account of its superessential union, ineffable and unknown to all secondary natures; but it is comprehended and known by its participants. Hence, that which is first, is alone perfectly unknown, as being imparticipable.

For all knowledge which subsists through reasoning and language, pertains to beings, and in beings possesses the apprehension of truth. For it comes into contact with conceptions, and subsists in intellections. But the Gods are beyond all beings. Neither, therefore, is that which is divine doxastic, or the object of opinion, nor is it dianoëtic, nor intelligible. For every being is either sensible, and on this account doxastic, or truly existing being, and on this account intelligible, or it is between these, subsisting as being and at the same time generation, and on this account is dianoëtic. If, therefore, the Gods are superessential, and subsist prior to beings, there is neither any opinion of them, nor science and dianoia, nor intellection. But the nature of their peculiarities is known by the beings that are suspended from them. And this by a necessary consequence. For the differences of participants are co-divided conformably to the peculiarities of the participated natures. And neither does every thing participate of every thing; for there is no co-ordination of things perfectly dissimilar. Nor does any casual thing participate of that which is casual. But that which is kindred is conjoined to that which is kindred, and proceeds from that to which it is allied.