I'VE HAD A SORE ELBOW for the past week or so.

I have no idea when or where I hurt it, or how long it will take to heal—except that it is taking too long. I just know that whenever I move it in the wrong way, it hurts: a kind of deep ache which is very unpleasant.

I don't bring this up to ask for your sympathy, though I appreciate any that comes my way.

I bring it up because it gets to the heart of the whole idea of a natural spirituality.

This ache, this pain, is not really in my elbow.

On one hand, it's quite possible for people to feel pain in limbs that have been amputated. On the other hand, we are all pretty sure that an amputated arm, from the time it is no longer attached to a body, does not feel anything at all.

My brain is the organ that does the feeling. It receives messages from the nerves in my arm, interprets those messages, and only then do I feel anything.

If the nerves that carry the messages to my brain die, I either cease to feel the body part they are connected to, or I feel things that are not there, like the people who experience phantom limbs.

I actually have a small spot on one leg where a nerve has been damaged. You can prick me with a pin there, and I feel nothing—no message gets through.

Insofar as the pain is anywhere at all, most of us would agree that it is "really" in my brain.

And yet I began this post by saying the pain was in my elbow, and you knew exactly what I meant by that.

So what's going on?

It's tempting at this point to retreat to a sort of medieval reasoning, and to talk about different senses of location.

I could say that the pain is in my elbow in a "spiritual" sense, but in my brain in a "physical sense", and spin off, from there to a series of fine metaphysical distinctions.

Something very like this was the basis of the famous question about how many angels could sit on the tip of a pin.

But there's a much simpler, and more interesting, explanation.

It has to do with knowledge, and the way we experience the world, and, ultimately, it has to do with the whole idea of spirituality.

To be continued...