The Six Books of Proclus on the Theology of Plato, Volume 1

In the third place therefore, the genus of true science is said to be established about the supercelestial place. For these two things ascend to the contemplation of that essence, viz. intellect the governor of the soul (but this is a partial intellect established indeed above souls, and elevating them to their paternal port) and true science which is the perfection of the soul. This therefore energizes about that place, as transitively revolving in harmonic measures about being. But intellect contemplates it, as employing simple intellection. Farther still, the science which is in us is one thing, but that which is in the supercelestial place another. And the former indeed is true, but the latter is truth itself. What therefore is it, and whence does it subsist? It is indeed a deity which is the fountain of all intellectual knowledge, and the first efficient cause of undefiled and stable intelligence.[219] But it shines forth in the first triad of intellectuals, because this is perfective of all other things and likewise of divine souls. For these ascending to this uniform power of all knowledge, perfect their own knowledge. For each of the undefiled souls, says Socrates, revolving together with Jupiter and the heaven, surveys justice, temperance and science. Hence, these three fountains are there, being intelligible deities, and the fountains of the intellectual virtues, and not being, as some think they are, intellectual forms.

For Plato is accustomed to characterize these by the term itself, as for instance science itself and justice itself; and this Socrates says somewhere in the Phædo. But here when he says justice herself, temperance herself, and science herself, he appears to unfold to us certain self-perfect and intelligible deities, which have a triadic subsistence. And of these science indeed is the monad; but temperance has the second order; and justice the third. And science indeed is the supplier of undefiled, firm and immutable intelligence; but temperance imparts to all the Gods the cause of conversion to themselves; and justice imparts to them the cause of the distribution of the whole of good according to desert. And through science indeed, each of the Gods intellectually perceives the natures prior to himself, and is filled with intelligible intelligence;[220] but through temperance he is converted to himself, and enjoys a second union, and a good coordinate to the conversion to himself; and through justice he rules over the natures posterior to himself, in a silent path, as they say, measures their desert, and supplies a distribution adapted to each. These three fountains therefore contain all the energies of the Gods. And science indeed proceeds analogous to the first triad of intelligibles. And as that triad imparts essence to all things, so this illuminates the Gods with knowledge. But temperance proceeds analogous to the second triad of intelligibles.

For temperance imitates the connective and measuring power of that triad; since it measures the energies of the Gods, and converts each of them to itself. And justice proceeds analogous to the third triad of intelligibles. For it also separates secondary natures according to appropriate desert,[221] in the same manner as that triad separates them intelligibly by the first paradigms.