Sorry, but Catholics don't condemn Harry Potter.
Some do, and some say that it is a good yarn that helps kids respect right and wrong. If you refer to Paul, it's like his argument about pagan gods: he says some people say these gods are not real, and others say they are real and need to be shunned.
As for mentioning God: Catholics are't usually big about bragging or pushing God to others. (except for former Protestants and for a small group who actually preach or explain the faith in some forums).
Catholics teach with stories, and see God and us as a family relationship.
Were you aware that most of the 911 firefighters were Catholic? Many were devout. Yet few reported it. Catholics just absorb the idea of love of neighbor and self sacrifice as part of their faith.
In LOTR, you don't see sociopaths, but men with flaws who seek to do the right thing, without making a big deal about it. They take responsibility. They tell stories. They like to party. They protect each other, even would die for each other, because they know that's what the world is about...but they aren't big about praying out loud and saying praise Jesus. They obey the natural law and have reverence for nature, for others, and for a higher power (note the times when they call on Elbereth, or the discussion where Frodo is told he is MEANT to find the ring-- but not by it's maker).
Gandalf was an incarnated Angel in Tolkiens's theology, so his magic is natural. Humans who seek occult power descend to evil (the ringwraiths and Boromir)...unlike Harry Potter, who learns to manipulate power as a human...this idea that occult/spiritual powers are not to be sought is a Jewish/christian idea also....
Pearce's explanations are Catholic mainly for other catholics.
However, a good Evangelical book which explores the pros and cons is : Tolkien in Perspective: by Greg Wright of the website Hollywood Jesus...
But what is the ring?