"Since a lower power acts in virtue of a higher power, a lower order performs actions proper to a higher order by acting in virtue of that higher power. But the higher orders possess in a more eminent way whatever is proper to the lower orders. Thus all things are in a certain sense common to the various orders. However, they receive their proper names from properties that are characteristic of each order. Nevertheless the lowest order of all retains the common name of angels for itself, for the reason that it acts, as it were, in virtue of all the rest. Furthermore, since the higher naturally influences the lower, and since intellectual action consists in instructing or teaching, the higher angels, in instructing the lower angels, are said to purify, illuminate, and perfect them."