Don't get me wrong, I enjoy the Harry Potter books and movies. But I was watching one with my daughter last night, and I was struck once again by the fact that J.K. Rowling just didn't seem to bother working out any sort of logic to the magic in the books. Yes, we have to suspend disbelief and grant that magic and witchcraft exist in the fictional world, but having granted that, we should then find a logical consistency in how they operate there.
However, in Harry Potter, what the heck is up with this "magic training"? The kids go to a class, and the teacher tells them to say "gaudiamus igitur," "vini, vidi, vici," or some such phrase, and... well, that's it! There seems to be nothing else to these spells at all. And yet there must be, because Ron Weasely's spells always go wrong. But with the single exception of the "Patronus," I've never seen any hint as to what the other thing could be, nor seen any student getting instruction as to how their spell went wrong. What are the teachers even there for?
And just what do wizards have power over? You see a spoon stirring a pot of food by itself at the weasley's, or a broom sweeping up without anyone there, and it seems as though they might have complete power over any physical object. And yet they write with pens, grab the quidditch ball by hand, and ride an ordinary train to Hogwarts. Why? Is it just too boring to do everything by magic? Is there some reason they can control brooms and not pens? Maybe in Rowling's mind this all makes sense, but I've never seen any explanation.
And it irks me, because I hate to see an enjoyable series constantly marred by what appears to be pure sloppiness.