Summa Theologica, Part I (Prima Pars) From the Complete...

Objection 1: It would seem that one angel does not enlighten another. For the angels possess now the same beatitude which we hope to obtain. But one man will not then enlighten another, according to Jer. 31:34: "They shall teach no more every man his neighbor, and every man his brother." Therefore neither does an angel enlighten another now.

Obj. 2: Further, light in the angels is threefold; of nature, of grace, and of glory. But an angel is enlightened in the light of nature by the Creator; in the light of grace by the Justifier; in the light of glory by the Beatifier; all of which comes from God. Therefore one angel does not enlighten another.

I answer that, One angel enlightens another. To make this clear, we must observe that intellectual light is nothing else than a manifestation of truth, according to Eph. 5:13: "All that is made manifest is light." Hence to enlighten means nothing else but to communicate to others the manifestation of the known truth; according to the Apostle (Eph. 3:8): "To me the least of all the saints is given this grace . . . to enlighten all men, that they may see what is the dispensation of the mystery which hath been hidden from eternity in God." Therefore one angel is said to enlighten another by manifesting the truth which he knows himself. Hence Dionysius says (Coel. Hier. vii): "Theologians plainly show that the orders of the heavenly beings are taught Divine science by the higher minds."

Now since two things concur in the intellectual operation, as we have said (Q. 105, A. 3), namely, the intellectual power, and the likeness of the thing understood; in both of these one angel can notify the known truth to another. First, by strengthening his intellectual power; for just as the power of an imperfect body is strengthened by the neighborhood of a more perfect body—for instance, the less hot is made hotter by the presence of what is hotter; so the intellectual power of an inferior angel is strengthened by the superior angel turning to him: since in spiritual things, for one thing to turn to another, corresponds to neighborhood in corporeal things. Secondly, one angel manifests the truth to another as regards the likeness of the thing understood. For the superior angel receives the knowledge of truth by a kind of universal conception, to receive which the inferior angel's intellect is not sufficiently powerful, for it is natural to him to receive truth in a more particular manner. Therefore the superior angel distinguishes, in a way, the truth which he conceives universally, so that it can be grasped by the inferior angel; and thus he proposes it to his knowledge. Thus it is with us that the teacher, in order to adapt himself to others, divides into many points the knowledge which he possesses in the universal. This is thus expressed by Dionysius (Coel. Hier. xv): "Every intellectual substance with provident power divides and multiplies the uniform knowledge bestowed on it by one nearer to God, so as to lead its inferiors upwards by analogy."

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. _______________________

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.

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.

But on the part of the power the will cannot be moved at all save by God. For the operation of the will is a certain inclination of the willer to the thing willed. And He alone can change this inclination, Who bestowed on the creature the power to will: just as that agent alone can change the natural inclination, which can give the power to which follows that natural inclination. Now God alone gave to the creature the power to will, because He alone is the author of the intellectual nature. Therefore an angel cannot move another angel's will.

Reply Obj. 1: Cleansing and perfecting are to be understood according to the mode of enlightenment. And since God enlightens by changing the intellect and will, He cleanses by removing defects of intellect and will, and perfects unto the end of the intellect and will. But the enlightenment caused by an angel concerns the intellect, as explained above (A. 1); therefore an angel is to be understood as cleansing from the defect of nescience in the intellect; and as perfecting unto the consummate end of the intellect, and this is the knowledge of truth. Thus Dionysius says (Eccl. Hier. vi): that "in the heavenly hierarchy the chastening of the inferior essence is an enlightening of things unknown, that leads them to more perfect knowledge." For instance, we might say that corporeal sight is cleansed by the removal of darkness; enlightened by the diffusion of light; and perfected by being brought to the perception of the colored object.

Reply Obj. 3: The Philosopher speaks of the lower sensitive appetite which can be moved by the superior intellectual appetite, because it belongs to the same nature of the soul, and because the inferior appetite is a power in a corporeal organ. But this does not apply to the angels. _______________________

Objection 1: It would seem that an inferior angel can enlighten a superior angel. For the ecclesiastical hierarchy is derived from, and represents the heavenly hierarchy; and hence the heavenly Jerusalem is called "our mother" (Gal. 4:26). But in the Church even superiors are enlightened and taught by their inferiors, as the Apostle says (1 Cor. 14:31): "You may all prophesy one by one, that all may learn and all may be exhorted." Therefore, likewise in the heavenly hierarchy, the superiors can be enlightened by inferiors.