The problem with these so-called 'spontaneous regressions' is that they have no scientific explanations behind them, they are not - as far as anyone knows - repeatable, and we have no idea what other influences that might have been being brought to bear on the situations leading up to them. As such, they do not fit any of the tidy patterns that science - in this case, medical - likes to develop.
Absolutely agree. The correct thing to do, therefore, is to say 'We don't know', not to say 'It must have been papal saliva!'.
The problem with that argument, O, is that all that you refer to is within the context of sceintific knowledge. As I pointed out above, all the regressions/healings are outside that context. Lest you forget, its folk like yourself who erect the parameters that limit the areas that science can deal with. I happen to believe that those parameters are unrealistically limiting.
Spontaneous regression isn't making a scientific claim, it's saying that so far as we can see there's no obvious cause. When people make claims of other causes we can investigate scientifically and show that there is no reason to think those explanations are the case.
It might very well be special Christian magic done by the Pope, but in the absence of a mechanism, or any reliable way to determining why that time it worked and other times it doesn't, Papal magic is indistinguishable from 'we don't know', or from a placebo.
Spontaneous regression, as a phrase, isn't a presumption of a natural cause, it's an admission of 'we don't know'. To try to fit magical explanations in would be equally wrong.
O.