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

Of every intellectual series, some things are divine intellects, receiving the participations of the Gods; but others are intellects alone. And of every psychical series, some things are intellectual souls, suspended from their proper intellects; but others are souls alone. Of all corporeal natures, likewise, some have souls supernally presiding over them, but others are natures alone, destitute of the presence of souls.

For of each series, not the whole genus is adapted to be suspended from that which is prior to itself, but that which is more perfect in it, and sufficient to be connascent with superior natures. Neither, therefore, is every intellect suspended from deity, but those intellects only which are supreme and most single. For these are allied to the divine unities. Nor do all souls participate of participable intellect,[258] but such only as are most intellectual. Nor do all corporeal natures enjoy the presence of soul, and of the soul which is participated, but those only that are more perfect, and possess in a greater degree the form of reason. And this is the mode of demonstration in all things.