So whatever Tolkien meant, it certainly wasn't a primer on
deconstruction! Frodo was more sensitive to the difference between
right and wrong, good and evil, love and hate, etc., not less. As I said
below, Frodo had left Plato's cave, where the rest of the world tries to make
sense of shadows, and had entered the world of ideals, where saints and
philosophers abide. Frodo did not leave Middle-earth because he saw
things less clearly, but because he saw them too clearly. Tolkien is an
orthodox religious idealist. I can't think of anyone less likely to
embrace the theory of deconstruction.
If you want to use the theory of deconstruction to analyze LotR, you can show
how the internal logic of LotR breaks down, until it becomes so inconsistent
that Tolkien's fantasy is no longer believable. This is rather
simple. Since everything in Tolkien's world comes from Eru, including
evil, then how can Eru be good? There is no logical answer to that
question. You either accept Eru's goodness on faith, or you don't, and
fall back on the meaninglessness of life. Meaninglessness does have its
positive side, by the way. It can be freeing. But Tolkien created a
world filled with meaning. If we see it as meaningless, then we are
attacking Tolkien, not learning from
him.
“I dislike Allegory - the conscious and intentional allegory - yet any attempt to explain the purport of myth or fairytale must use allegorical language. (And, of course, the more 'life' a story has the more readily will it be susceptible of allegorical interpretations: while the better a deliberate allegory is made the more nearly will it be acceptable just as a story.)” (From Tolkien Letter # 131.)