It is one of the most studied books in modern history. The Silmarillion was to be J.R.R. Tolkien's magnum opus. Instead, it turned out to be the unfulfilled promise of his great writing career. A new article in the Wall Street Journal offers at least a partial explanation of why Tolkien could not finish the work that many scholars agree would have been the crowning achievement of his lifetime.

In a 1992 interview for the JRRT centennial video, Christopher Tolkien said: "[The Silmarillion] had simply become too big...he was too tired. Too old, too tired."

He was probably much closer to the truth than people realized, according to Johah Lehrer, who writes in Fleeting Youth, Fading Creativity that poets reach their peak creativity before novelists, and scientists often peak in their 20s and 30s.

Tolkien was a poet, scientist, and novelist all wrapped up into one man's mind. Drawing on research Dean Simonton and Adolphe Quetelet, the Lehrer article recaps how creative individuals often realize their greatest achievements relatively early in life. A few exceptions, such as Thomas Hardy, change course and peak in creativity a second time or later in life.

Tolkien first attempted to construct a coherent mythical cycle during his early 20s when he nearly completed The Book of Lost Tales, his mythology for England. For reasons we'll never fully be sure of, however, he lost steam and in fact switched modes. By the age of 26 Tolkien had written some epic-length poems ("Lay of Leithian" and "The Lay of the Children of Hurin"), the like of which he never composed again.

At this stage in his career Tolkien returned to writing prose fiction but his energies were divided between creating a literary epic he self-styled The Silmarillion and various children's fantasy stories. Roverandom, The Father Christmas Letters, and The Hobbit came out of these years, followed by Mr. Bliss, Smith of Wootton Major, and Farmer Giles of Ham.

Of course, Tolkien's passion for linguistic studies pervaded all of his fiction and poetry. The Silmarillion, enlightened by Tolkien's philological roots, invariably crept into every story he turned his thoughts to. The ancient forgotten world of Elves and heroic Men wanted to be heard and seen.

Very much like Einstein's pursuit of a unified theorem for physics, Tolkien spent almost his entire adult life trying to tell the stories of The Silmarillion. His attempts became sidetracked, diverted by necessity, other interests, and demands from his publishers. Had George Allen & Unwin not asked for a sequel to The Hobbit, The Lord of the Rings most likely would never have been written.

Adolphe Quetelet's research into the creativity of French and English playwrights revealed that the writers were most productive between the ages of 25 and 50. Tolkien had finished the primary text for The Lord of the Rings by Autumn 1948, when he was 56. Over the next few years he tidied up the prose and added the appendices but the bulk of the work was completed by 1952, when he turned 60.

The energy of his youth was mostly spent, and though Tolkien worked on Middle-earth stories for the next 20 years he only published one more book, The Adventures of Tom Bombadil. He might have been developing a companion volume for The Lord of the Rings during the late 1950s and through the middle 1960s, of which the surviving texts Christopher Tolkien published in Unfinished Tales of Numenor and Middle-earth.

The Silmarillion itself languished despite numerous attempts to annotate outdated versions of the story in preparation for a new attempt to tell it. The old fires took a very long time to die but they were outshone by the sparks they cast across the literary world. In the last year of his life Tolkien had begun pondering tossing out the entire cycle and starting over, much to the dismay of many of his followers (when we learned as much from post-humous books).

I think that Tolkien's own predilection for introspective discovery played the largest role in undermining his efforts to produce a finished Silmarillion. But it could very well be that the core work, completed in the 1930s, was as good as it could ever get simply because -- like Fëanor, who could only make the Silmarils once -- he spent that part of his spirit already that was destined to produce The Silmarillion.

Maybe if he had not turned his thought to hobbits and the final departure of the Eldar from Middle-earth JRRT might have wound down his epic history. But would it have found a publisher at all? Would it have become anything more than a footnote in the history of fantasy literature?

It may be that only through the lens of The Lord of the Rings could we ever hope to see The Silmarillion as its author thought it should be seen: distant, far-off, compelling, and resounding with the echoes of lost ages.

What new research suggests, however, is that those ages are the lost ages of youth's creativity, and to those faintly remembered, enchanting shores the talented Mr. Tolkien was doomed never to sail again, despite his endless quests and voyages on the seas of imagination to catch one last glimpse of Valinor.

The limits of human capability determined that it could not get any better than it is, because Tolkien had already given The Silmarillion all that he had to give it.