Contrary to the predominant interpretation of many scholars and readers, the term creation actually held for Tolkien much the same specific meaning as an exclusively divine activity given it by St. Thomas, and what is more, far from this point being of mere semantic significance, according to Tolkien at least, a right understanding of this matter struck at the very heart of the meaning of his entire mythology.
Tolkien’s most in-depth discussion of the issue comes in the same reply to Peter Hastings I’ve cited previously. One of Hastings’s additional objections to Tolkien’s mythology concerned Treebeard’s statement in The Two Towers that the “Dark Lord” had, in Hastings’s words, “created the Trolls and the Orcs” (L 187, emphasis added). According to Humphrey Carpenter, editor of Tolkien’s published Letters, “Hastings suggested that evil was incapable of creating anything, and argued that even if it could create, its creatures ‘could not have a tendency to good, even a very small one’; whereas, he argued, one of the Trolls in The Hobbit, William, does have a feeling of pity for Bilbo” (L 187). On Hastings’s assumption, evil cannot create because creation means the production of something good, whereas evil can only produce something like itself, namely evil. It is even possible that Hastings—he was the manager of the Catholic bookshop in Oxford—had Thomas’s well-known discussion of divine goodness at the beginning of the Summa Theologiae somewhere in mind. As Thomas argues there, “everything seeks after its own perfection; and the perfection and form of an effect consist in a certain likeness to the agent, since every agent makes its like; and hence the agent itself is desirable and has the nature of good” (ST 1.6.1). Every effect is like its cause, so that whatever is good in the effect must preexist in its cause. But if a cause is wholly evil, as Hastings seems to have assumed to be the case with Sauron and Melkor, then it stands to reason that any effects they might produce, as Hastings put it, “could not have a tendency to good, even a very small one.”
On purely Thomistic grounds, of course, Hastings’s starting premise is problematic, since for Thomas no existing thing, including Sauron or Melkor, can in fact be wholly or entirely evil, inasmuch as existence itself remains a work of God and hence a “good,” a point that Tolkien himself implies toward the end of his letter to Hastings. In any event, Hastings adds the qualification that, even if an evil being were allowed the ability to create, whatever it created must, like itself, be evil. Thus, notwithstanding his objections to Tolkien, Hastings actually leaves open the possibility of, first, good yet finite creatures being able to create, and secondly, of even evil finite beings such as Sauron and Melkor being able to create provided that their creations exhibit the same constitutional tendency towards evil as themselves.
In a follow-up post, we’ll look at Tolkien’s reply to Hastings’s critique.
 “Unumquodque autem appetit suam perfectionem. Perfectio autem et forma effectus est quaedam similtudo agentis: cum omne agens agat sibi simile. Unde ipsum agens est appetibile, et habet rationem boni…”
 “Because by [God’s] accepting or tolerating their making—necessary to their actual existence—even Orcs would become part of the World, which is God’s and ultimately good” (L 195).