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

For it is either more excellent, or less excellent, or equal. Hence, that which is produced from this, will either also itself possess a power productive of something else, or it will be entirely unprolific. But if it is unprolific, according to this very thing it will be inferior to that by which it was produced. And through its inefficacy it is unequal to its cause which is prolific, and has the power of producing. But if it also is productive of other things, it either likewise produces that which is equal to itself, and this in a similar manner in all things, and all beings will be equal to each other, and no one thing will be better than another, that which produces, always giving subsistence in a consequent series to that which is equal to itself; or it produces that which is unequal to itself, and thus that which is produced, will no longer be equal to that which produces it. For it is the province of equal powers to produce equal things. The progeny of these, however, will be unequal to each other, if that which produces indeed, is equal to the cause prior to itself, but the thing posterior to it is unequal to it. Hence, it is not proper that the thing produced should be equal to its producing cause.

Moreover, neither will that which produces ever be less than that which is produced by it. For if it imparts essence to the thing produced, it will also supply it with essential power. But if it is productive of all the power which that posterior to it possesses, it will also be able to produce itself such as that posterior nature is. And if this be the case it will also make itself[206] more powerful. For impotency cannot hinder, productive power being present, nor a defect of will; since all things naturally aspire after good. Hence, if it is able to render another thing more perfect, it will also perfect itself before it perfects that which is posterior to itself. Hence, that which is produced, is not equal to, nor more excellent than, its producing cause. The producing cause, therefore, is in every respect better than the nature of the thing produced.