[ArGee]

It states that Gandalf uses every opening spell known to elves, men, and orcs.

Known to, but not used by. You could be right that there were men who used magic, but none in this story.

No Gandalf, the rest of the Istari or Sauron are not men, but the Ringwraiths were. They were Kings and Queens who were also powerful sorcerors.

I don't remember the reference to the Nazgul being sorcerers. Were they sorcerers before or after they ceased being men? I'll comment a little more about them later.

The Lord of the Nazgul is called "The Witch King" and the Mouth of Sauron was a man who was a powerful sorceror. So yes, men did wield magic.

And now to my other point about the Nazgul. Does Middle Earth contain stories of any men who use magic who remain its master? Or does the magic always overpower the man? That's a real question for you, since you seem to have read some of the other things written by Tolkein. I've only read The Hobbit and LOTR.

Shalom.

[Anitius Severinus Boethius]

You might want to read the Appendices at the End of The Return of the King, I think they deal with the Nazgul a bit. The Silmarillion is a great source of background, and the Histories of Middle Earth contain alot of stories and background. Off the top of my head, I can't recall a man who mastered magic and didn't come to a bad end, but I'm pretty sure there were a few with tales about them. The Numenorians were decended from Elros after all and they were very adept at magic.

But you are correct in that one of Tolkien's great themes is the corruption of power. Not just magic, but any power can corrupt in Middle-Earth and the wise know not to take for granted their power and not to use it too readily.