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

For it begins its energy upon secondary natures prior to that which is posterior to it, and is present in conjunction with the presence of it. When likewise that which is posterior to it no longer energizes, it is still present, and that which is more causal continues to energize. And this not only in different subjects, but likewise in each of the natures that sometimes participate. Thus it is necessary, for instance, that being should be first generated, afterwards animal, and afterwards man. And man, indeed, is not, if the rational power is absent, but there is still animal, breathing and sentient. And again, life failing, being remains. For though a thing does not live, yet it has existence. And there is a similar reasoning in all things.

The cause, however, of this is, that the more causal nature being more efficacious, energizes on the thing caused[236] prior [to that which is less causal]. For the thing caused participates first of that which is more powerful. And that which is secondary again energizing, that which is more powerful energizes with it. Because every thing which the secondary nature produces, that which is more causal produces likewise in conjunction with it. When the former also fails, the latter is still present. For the communication of the more powerful cause, operating in a greater degree, leaves that which participates it, posterior to the energy of the less powerful cause. For through the communication of the secondary nature, it corroborates its own illumination.