Do you believe in magic?

Orson Scott Card’s books on writing are outstanding, including his book on writing fantasy and SF. However, there’s one point on which I think he’s completely wrong.
In discussing world-building, Card states that because fantasy operates outside the normal rules, writers should spell out the rules of magic upfront, quickly and cleanly. Otherwise, readers will become completely lost figuring out how magic works.
On the contrary, I think most readers have no trouble going with the flow. Most people have been exposed to enough magic, at least in the form of fairy-tales or Disney films, that the idea of pointing a wand at someone and turning them into a frog doesn’t need explanation. It’s magic. That sort of stuff happens.
I was thinking of this while reading David Sklar’s excellent Shadow of the Antlered Bird this week. The book is the story of Tamnen, a half-sidhe desperately trying to get out from under his mother’s well-meaning thumb (she’s the sidhe half of his parentage); his efforts to do so, however, unleash a monster determined to hunt him down, one he may not have the power to stop.
There’s some explanation, along the way, of how magic works. Trees are aware. Traditional anti-magic protections such as salt and cold iron work fairly well. But there’s nothing that could be considered to spell out the principles—anything we do need to know is explained in passing (the closest thing to a law of magic is when Tamnen explains why magic and technology don’t mix).
What’s far more important is that the magic feels magical, like something eerie, strange and non-scientific (even when Tam exploits technology in various ways)—heck, not even logical as we normally think of it. The same is true of Sandman Slim, which I read earlier in the week (I’ll get to that in my next “Books and movies” post) or The Magician (flawed as I found other aspects, the magic is striking). I don’t know if any of these authors really have rules for magic worked out; what counts is, it feels like the rules are in place.
There are lots of ways to handle magic in fiction. It can be something that’s explained by advanced science, as in the classic science fantasies of A. Merritt; it can be presented as something that can be analyzed, as it is in Fritz Leiber’s Conjure Wife (where the protagonist figures out the underlying principles behind various spells, then improves on them); or as something that’s not scientific at all (Tolkien, I’ve been told, informed one scriptwriter trying to adapt LOTR that lembas—elven bread—is not something that can be explained by science; if it were under a microscope, the physical properties would be exactly identical to regular bread).
What matters is that the rules are internally coherent; the magic is consistent; and that it feels magical. If it’s done right, there’s no need to spell out the rules. We’ll feel them in our bones.