We cannot simply decide such things on the basis of one individual’s experiences, for the reasons described above: they might be mistaking the placebo effect for a real effect or mistaking a chance finding for a real one. Even if we had one genuine, unambiguous, and astonishing case of a person’s getting better from terminal cancer, we’d still be careful about using that one person’s experience, because sometimes, entirely by chance, miracles really do happen. Sometimes, but not very often.
