In a chapter on images for representing angels, Pseudo-Dionysius makes the case that “each of the many parts of the human body can provide us with images which are quite appropriate to the powers of heaven.” One such bodily image is that of teeth, which he allegorizes as as “hav[ing] to do with the skill which produces divisions in the intake of nourishing perfection, for it is a fact that every intelligent being, having received from one which is more divine the gift of a unified conception, proceeds to divide it and to make provision for its diffusion in order that an inferior may be lifted up as far as possible” (The Celestial Hierarchy, ch. 15, trans. Luibheid). In other words, the higher angels “chew” up more difficult, unified knowledge (the “bread of angels”), making it more digestible for the lower. While it’s not technically an example of mastication, thanks to Pseudo-D, here’s my new mental image for one angel “instructing” another:
A few other points of comparative angelology might be made between Tolkien and Aquinas. On language, Tolkien makes a remark in one letter that “the Valar had no language of their own, not needing one” (Letters 282), whereas Thomas argues that there is indeed a kind of “speech” among the angels (Summa Theologiae 1.107). (On the language or speech of the Ainur, see Flieger, Splintered Light, 61-2, and for a treatment of Thomas’s teaching concerning angelic speech, see Harm Goris, “The Angelic Doctor and Angelic Speech: The Development of Thomas Aquinas’s Thought on How Angels Communicate.”) Also consistent with St. Thomas’s angels is Tolkien’s insistence that, for all their sub-creative power, the Valar cannot perform miracles, which the creator alone can do, indicating that even in their sub-creative capacity the Valar are very much a part of the natural order (Letters 151, 194, 204, 235, and 411; Summa Theologiae 1.110.4). Finally, there is Tolkien’s agreement with Thomas that angels cannot know the mind of another being without the assent of its will (Summa Theologiae 1.57.4, “Whether Angels Know Secret Thoughts”; see also 1.111.2). As Tolkien stipulates,
No one, not even one of the Valar, can read the mind of other ‘equal beings’: that is one cannot ‘see’ them or comprehend them fully and directly by simple inspection. One can deduce much of their thought, from general comparisons leading to conclusions concerning the nature and tendencies of minds and thought, and from particular knowledge of individuals, and special circumstances. But this is no more reading or inspection of another mind than is deduction concerning the contents of a closed room, or events taken place out of sight. Neither is so-called ‘thought-transference’ a process of mind-reading: this is but the reception, and interpretation by the receiving mind, of the impact of a thought, or thought-pattern, emanating from another mind, which is no more the mind in full or in itself than is the distant sight of a man running the man himself. Minds can exhibit or reveal themselves to other minds by the action of their own wills (though it is doubtful if, even when willing or desiring this, a mind can actually revel itself wholly to any other mind). (Morgoth’s Ring 398-9).