18. Those are powers to whom hostile virtues are subject, and they are called by the name of powers because evil spirits are constrained by their power not to harm the world as much as they desire.
19. Principalities are those who are in command of the hosts of the angels. And they have received the name of principality because they send the subordinate angels here and there to do the divine service....
20. Dominions are they who are in charge even of the virtues and principalities, and they are called dominions because they rule the rest of the hosts of the angels.
21. Thrones are the hosts of angels who in the Latin are called sedes; and they are called thrones because the creator presides over them, and through them accomplishes his decisions.
22. Cherubim ... are the higher hosts of angels who, being placed nearer, are fuller of the divine wisdom than the rest....
24. The seraphim in like manner are a multitude of angels, and the word is translated from the Hebrew into the Latin as ardentes or incendentes, and they are called ardentes because between them and God no other angels stand, and therefore the nearer they stand in his presence the more they are lighted by the brightness of divine light.
25. And they veil the face and feet of God sitting on his throne, and therefore the rest of the throng of angels are not able to see fully the essence of God, since the seraphim cover him.
28. To each and every one, as has been said before, his proper duties are appointed, and it is agreed that they obtained these according to merit at the beginning of the world. That angels have charge over both places and men, an angel testifies through the prophet, saying: “Princeps regni Persarum mihi restitit” (Dan. x. 13).
29. Whence it is evident that there is no place that angels have not charge of. They have charge also over the beginnings of all works.
30. Such is the order or classification of the angels who after the fall of the wicked stood in celestial strength. For after the apostate angels fell, these were established in the continuance of eternal blessedness.