Well IIRC Orcs/Goblins are probably immortal (or pretty close) as well as there was a discussion between Orcs/Goblins at some point in the book that referenced a battle they personally had been in hundreds or thousands of years before.
Perhaps. Or maybe it could be summed up with two words: The Somme. As a young lieutenant he witnessed the deaths of his friends and fellow soldiers far more than anyone could stand, thankyouverymuch, and I imagine would yearn for a near-deathless world, if only in his imagination.
DD
I’m absolutely positive that that was a part of it. He was as a schoolboy part of a four-boy coterie of close friends, two of whom died in World War I. He and the other survivor helped arrange for the publication of one of the two casualties’ poems in book form, as a memento.
But another portion is that he (and Lewis) were steeped in “classical” literature (meaning both Classical in the strict sense and material from medieval, Renaissance, and early modern times) to a far greater degree than probably anyone on this board, including our members who are professors of literature. It was a part of the standard Oxford education of the day. And Lewis in The Discarded Image goes into quite a bit of depth about what he terms “the Longaevi,” the natural-yet-supernatural figures that are tied to the world until its end, long of life and in a way immune to time, some of which were seeking an end to their age-old world-weariness. That almost certainly played a major role in his conception of the Elves.
Here’s a nice little commentary on what is known about orc mortality/immortality. JRRT kept the waters sort of muddied, as you’ll see.
http://tolkien.slimy.com/faq/Creatures.html#OrcDeath