Reply Obj. 1: All the angels, both inferior and superior, see the Essence of God immediately, and in this respect one does not teach another. It is of this truth that the prophet speaks; wherefore he adds: "They shall teach no more every man his brother, saying: 'Know the Lord': for all shall know Me, from the least of them even to the greatest." But all the types of the Divine works, which are known in God as in their cause, God knows in Himself, because He comprehends Himself; but of others who see God, each one knows the more types, the more perfectly he sees God. Hence a superior angel knows more about the types of the Divine works than an inferior angel, and concerning these the former enlightens the latter; and as to this Dionysius says (Div. Nom. iv) that the angels "are enlightened by the types of existing things."
Reply Obj. 2: An angel does not enlighten another by giving him the light of nature, grace, or glory; but by strengthening his natural light, and by manifesting to him the truth concerning the state of nature, of grace, and of glory, as explained above.
Reply Obj. 3: The rational mind is formed immediately by God, either as the image from the exemplar, forasmuch as it is made to the image of God alone; or as the subject by the ultimate perfecting form: for the created mind is always considered to be unformed, except it adhere to the first truth; while the other kinds of enlightenment that proceed from man or angel, are, as it were, dispositions to this ultimate form. _______________________
SECOND ARTICLE [I, Q. 106, Art. 2]
Whether one angel moves another angel's will?
Objection 1: It would seem that one angel can move another angel's will. Because, according to Dionysius quoted above (A. 1), as one angel enlightens another, so does he cleanse and perfect another. But cleansing and perfecting seem to belong to the will: for the former seems to point to the stain of sin which appertains to will; while to be perfected is to obtain an end, which is the object of the will. Therefore an angel can move another angel's will.
Obj. 2: Further, as Dionysius says (Coel. Hier. vii): "The names of the angels designate their properties." Now the Seraphim are so called because they "kindle" or "give heat": and this is by love which belongs to the will. Therefore one angel moves another angel's will.
Obj. 3: Further, the Philosopher says (De Anima iii, 11) that the higher appetite moves the lower. But as the intellect of the superior angel is higher, so also is his will. It seems, therefore, that the superior angel can change the will of another angel.
On the contrary, To him it belongs to change the will, to whom it belongs to bestow righteousness: for righteousness is the rightness of the will. But God alone bestows righteousness. Therefore one angel cannot change another angel's will.
I answer that, As was said above (Q. 105, A. 4), the will is changed in two ways; on the part of the object, and on the part of the power. On the part of the object, both the good itself which is the object of the will, moves the will, as the appetible moves the appetite; and he who points out the object, as, for instance, one who proves something to be good. But as we have said above (Q. 105, A. 4), other goods in a measure incline the will, yet nothing sufficiently moves the will save the universal good, and that is God. And this good He alone shows, that it may be seen by the blessed, Who, when Moses asked: "Show me Thy glory," answered: "I will show thee all good" (Ex. 33:18, 19). Therefore an angel does not move the will sufficiently, either as the object or as showing the object. But he inclines the will as something lovable, and as manifesting some created good ordered to God's goodness. And thus he can incline the will to the love of the creature or of God, by way of persuasion.