I have written previously about the plain but unspoken pattern concerning magical items in Middle Earth. For each of the three ages of the sun, there is a set of magic items that corresponds to them -- Silmarils for the first age, rings in the second, and Palantiri in the third. Each set of artifacts seems to bring more grief than joy, especially as regards the silmarils and the rings. (Not so much the Palantiri. They corrupted two great figures but, as has been pointed out to me, a third great figure was able to resist Sauron's gaze through the Palantir, and moreover the rest were never implied to be malevolent.)
There is another unspoken pattern in the legendarium, chiefly concerning Balrogs. There are three instances in the text where a great hero slays a balrog, and each of these heroes dies as a result of there efforts. Ecthelion drowns Gothmog in a fountain and drowns with him. Glorfindel drives a balrog off a cliff and falls with him. Gandalf breaks a bridge under Durin's Bane and...falls with him. (And then fights him all the way up the endless stair and then dies. Ecthelion didn't have nearly as much trouble handling Gothmog, for some reason.)
I find the last pattern intriguing, because it characterizes the aspects of the legendarium that resemble Norse mythology. In the Norse tales, heroes went and fought even if they knew they wouldn't win. At Ragnarok they fight against the fire-demon Surt even though they know they're doomed. Doom is not an excuse to give up. Likewise Tolkien's characters repeatedly throw themselves at Balrogs, and Gandalf, knowing he's not going to survive the encounter, stops the great balrog of Moria anyway.
This is in contrast to the aspects of the legendarium that seem to distrust magic as much as a staunch Catholic would.
There is a third unspoken pattern in the legendarium, and one that concerns me. Namely, that there are five female figures in the Lord Of The Rings: Rosie Cotton of the Shire, Arwen of Rivendell, Galadriel of Lothlorien, Eowyn of Rohan, and Shelob of Cirith Ungol. Each of these women characterizes the region they reside in, and though some are willing to leave their regions to go to war, not a one is ever stated to talk to another.
I am bothered by Tolkien's account of the women of his tale, though not as much as I might be. Tolkien makes sure that at least four of his female characters actually DO something. Or three, depending on how you judge Arwen's actions; or three, depending upon whether you consider an appendix tale to count towards Galadriel's status as an active character. In any case Shelob is on the list because she's clearly a character with a mind, motivation, and malice. Instead of just sitting around being an object of veneration like some fair lady in a courtly ballad, four out of these five women have a crucial role in the plot, both within the sight of the Fellowship and out of their sight. In some ways, Arwen and Galadriel resemble the more realistic approach to Medieval noblewomen, which is to have them run and defend the house while the men go off to war.
And yet...none of the female characters ever talks to each other in the text. What have they to say to each other regarding the journeys of the princes of the realms? Are any of them friends? What relationship does Arwen have to her grandmother Galadriel? Do they talk about the loss of Celebrian? Tolkien does not care to make it clear, so we shall not know.
(This is less of a problem in The Silmarilion, where Galadriel is friends with Melian, and Luthien does most of the work to get the Silmaril, and sings her way out of death.)
Admittedly Tolkien's legendarium is very much a big-picture story, and by the time the tale gets out of Bree it has absolutely no concern for the lives of any but the great players. The inkeeper of the Prancing Pony is the last commoner that the text cares to deal with, all the way until the Scouring of the Shire.
There's a lot about the world of Middle Earth that's strange but I'll get to the issue of geography in a later writeup.