There was an experiment reported in New Scientist which claimed to have a control group not prayed for. I wondered a) just how they made sure that no-one prayed for the control group, and b) just what sort of deity would go along with such an experiment (since they were discussing prayer rather than non-deity assisted healing). I also remember a short story by Zenna Henderson on the same theme, in which the protagonist refused to abstain from praying as she gave blood.

The serious implication of this is that, if it works, we have an obligation to do it.

Penny