HOwever, unlike Harry potter, where children are encouraged to "develop" their psychic powers, in LOTR, one very strong theme is that such powers are forbidden, and that if one uses such powers even to do good, one will become corrupted to evil in the end...
I believe this is a misreading of Tolkien.
"Magic" in Tolkien is morally neutral, it is merely the Middle Earth equivalent of todays science and technology. It can be used for either good or evil, although certain types of "magic" are inherently evil, just as certain types of scientific research are. For instance, those that would require experimentation on unwilling human subjects.
Gandalf, the other good wizards and the elves routinely use magic without it inherently leading to evil. All of the elven kingdoms of The Silmarilion are based on what we would call magic. The implication is that the men of Numenor were also great magicians, otherwise how could they have defeated and captured Sauron? (Even if his submission was partly feigned.)
What is portrayed in Tolkien as inherently and always evil is the desire to dominate other sentient beings, crushing their God-given free will. This is true whether the method used is military force or "magic."
Domination is so against the will of God that even Tolkien's "angels" or demi-gods, the Valar, refuse to go down such a path, even when it is the only way to prevent great evil. If truly superhuman entities such as the Valar cannot dominate others in a righteous way, how can those who are merely human do so?
(Hobbits, ents, elves and dwarves are all on the same plane as Men in Tolkien. Some "species" or individuals have differing powers, abilities or destinies, but it is clear that none are superior beings in God's eyes.)
I think what gives people the idea that Tolkien portrays magic itself as evil is that he portrays the One Ring as inherently evil. But I believe that is because the Ring was made to dominate, not because it used magic.
Inscribed on the Ring was, "One Ring to rule them all. One Ring to find them. One Ring to bring them all, and in the darkness bind them." As precise a definition of evil as Tolkien could come up with.
This built-in obsession with domination was what made the One Ring evil. After all, the three elven Rings were good (although perhaps misguided), the seven Dwarven rings were portrayed as more or less amoral, and the nine Rings of men were evil perhaps only because the one Ring had collected and dominated them and their bearers.
Tolkien was making, I believe, a much more important point than that "magic" is evil. After all, very few of us will ever have to resist the temptation to use "real magic."
OTOH, the temptation to enforce our own opinions and beliefs on others, perhaps in the belief that we are "right," crushing their God-given free will, is a temptation any of us might face.
Even, perhaps especially, sincere Christians.
Thanks for that, Restorer.
(Though I might argue that the white-tipped cane of objective inquiry that is Science and the morally neutral tool that is Technique are increasingly morphed into Magic which not only Dominates, reshapes, retools, manufactures beings and binds men but "changes everything" ... including what we used to call self-evident truth. Science and technology -- in their present forms, anyway -- are not the replacement of white magic but, rather, the Ring.)
You are right, but I am right also.
You see, the problem is how we define the word "magic".
In letter 131, Tolkien admits this problem, and connects it with the fall of man and fall of the angels (i.e. Melkor, the angel who did not follow God but decided to make the earth as his own fiefdom, so earth and all things in it are tainted with evil).
"I have not used 'magic' consistently, and indeed the Elven queen Galadriel is obliged to remonstrate with the Hobbits on their confused use of the word both for the devices and operations of the Enemy, and for those of the Elves. I have not, because there is not a word for the latter (since all human stories have suffered the same confusion). But the Elves are there (in my tales) to demonstrate the difference. Their 'magic' is Art, delivered from many of its human limitations...and its object is Art, not Power, subcreation, not domination and the tyrannous reforming of Creation...The Enemy, in successive forms, is always 'naturally' concerned with sheer Domination, and so (is) the Lord of Magic and machines; but the problem (is): that this frightful evil can and does arise from an apparently good root: the desire to benefit the world and others...according to the benefactor's own plans..."
The men in Tolkien who use this "power" actually have elven blood, and so it is licit for them to use it (Aragorn and the Kings are descended from Elrond Halfelven's brother, who decided to remain mortal...
the elven rings were meant to preserve and to create new things, and to obtain wisdom, not to conquer.
The bad news is that Tolkien regarded modern machinery and technology as similar temptations to evil...since they, like "magic" were being used to manipulate and control creation..