[jwr]

In other words, you have no idea why the pain comes and goes, or why allergies come and go.

Which is fine.

I'm just trying to say that whenever we don't know, we have a tendency to reject and ridicule any new hypothesis, especially if it's in the field where we also have no idea on how to measure things. So, while agreeing that a scientific approach (measure, quantify, prove, etc) is better, I would not reject nor ridicule hypotheses that we can neither prove nor disprove. Personally, I find them interesting, as they lie on the boundary of what we know and might offer promising research in the future.

[I don't want to pick up on your simplification wrt pain, so I'll just note it's huge. Psychosomatic pain is not about "perception" at all, it's real, and the symptoms are real.]