His desire to reconstruct a pre-scientific and pre-philosophical vision of reality notwithstanding, Tolkien’s mythical world is–quite deliberately–almost entirely devoid of any explicit religious or cultic expression or sentiment. Instead, Tolkien describes the world of The Lord of the Rings in one place as a “monotheistic world of ‘natural theology’” (220), suggesting the presence of a little old-fashioned, scholastic, rational theology in Tolkien’s history of Earth’s primeval past after all. One of the very first questions in any philosophical or natural theology, of course, is the question of God’s existence, of whether it can be known, and if so, how. Consistent with this, in his commentary on the Athrabeth, the first of the aforementioned “basic beliefs” of the Elves listed by Tolkien is their conviction that “[t]here exists Eru (The One); that is, One God Creator, who made (or more strictly designed) the World, but is not Himself the World” (MR 330).
Once again, moreover, the manner in which the Elves knew God to exist, as I hope to show in later posts, bears a certain likeness to the kind of rational, natural theology represented and developed by St. Thomas Aquinas. Although Thomas gives five distinct, albeit related arguments for God’s existence in the Summa, it is his celebrated fifth way, the so-called “teleological argument” or argument from design, that has the greatest bearing on our present interest in Tolkien and which I will accordingly focus on here. According to Thomas,
We see that things which lack knowledge, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that they achieve their end not by chance, but by design. Now whatever lacks knowledge cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence, as the arrow is directed by the archer. Therefore some intelligent being exists by whom all natural things are ordered to their end; and this being we call God. (ST 1.2.3)
In short, we experience in nature non-intelligent things acting purposefully, for an end, and if there is a purpose, there must be, if you will, a “purposer.”
As for the natural theology of Tolkien’s fiction, although inhabited, shaped, and governed by powerful beings whom he refers to as “gods,” he regards his fictional cosmos, as we have just seen, as a strictly monotheistic world. More than it merely being a monotheistic world in principle, and the relative lack of religious observance notwithstanding, he further indicates that it was also known and experienced to be a monotheistic world by its chief inhabitants. Of the ancient Númenórean race of men, for example, from whose lineage Aragorn and his fellow Dúnedain of The Lord of the Rings are descended, Tolkien writes: “They thus escaped from ‘religion’ in a pagan sense, into a pure monotheist world, in which all things and beings and powers that might seem worshipful were not to be worshipped, not even the gods (the Valar), being only creature of the One” (L 204). Of the Elves Tolkien similarly writes in his commentary on the Athrabeth that, even amongst the most rebellious of their race, “not one had ever entered the service or allegiance of Melkor himself, nor ever denied the existence and absolute supremacy of Eru” (MR 334). As noted above, that God existed and that he was the supreme authority over all things, in short, was a foundational tenet of the Elvish worldview.
 “Videmus enim quod aliquae quae cognitione carent, scilicet corpora naturalia, operantur propter finem: quod apparet ex hoc quod semper aut frequentius eodem modo operantur, ut consequantur id quod est optimum; unde patet quod non a casu, sed ex intentione perveniunt ad finem. Ea autem quae non habent cognitionem, non tendunt in finem nisi directa ab aliquo cognoscente et intelligente, sicut sagitta a sagittant. Ergo est aliquid intelligens, a quo omnes res naturales ordinantur ad finem: et hoc dicimus Deum.”