Sorcery

[Boromir88]

Raynor, if a thread were to ever come up about who was the more higher ranked I would be more than glad to continue the debate...and possibly even prove to you as to why the Mouth clearly out-ranked the Witch-King. But this thread is not meant for that discussion.

Then again, neither the mouthie (nor Aragorn) are "pure" man, so in his case it is allowed to master magic.

The problem is you seem to be disregarding the word 'learned':

and because of his cunning he grew even higher in the Lord's favour; and he learned great sorcery...

Tolkien was very much a linguist, and on the back of Letters he remarks that there wasn't one of his over 600,000 words (his guesstimate) that he didn't go over and consider. So, I don't think this should just be cast aside because of something he states in one of his letters.

Maybe I'm misreading, but I got the impression you were suggesting that since the Mouth, and Aragorn, would have some elvish blood in them, they naturally possessed the ability to use magic...where I disagree in that it was something (at least in the Mouth's case at this point) that he had to learn how to do. Perhaps he can potentially be magically capable, but it was still something he had to learn how to use.