This ploy is, however, not only dishonest in attempting to avoid investigation by unbelievers, but it very largely fails. In fact science can actually say surprisingly much about things about which it has no understanding by application of simple criteria that constitute little more than simple accounting. There are all sorts of claims being made for magnetic therapies by persons who are either users or sellers of these products. There are people who have used magnetic devices and believe sincerely in their efficacy. It is even possible that at least some of these claims may one day be rigorously substantiated, but please consider the following.
Humans are extremely ill-equipped to make judgements about subtle effects.
This is why researchers resort to the use of mechanical and electronic equipment for measurements of effects that are either intrisically small or must be known to high precision. The precise state of function of a human being is affected by a great multitude of interacting factors, including the general state of mind of the individual. Anecdotal evidence, even when real, must be the beginning of a rigorous investigation, not the end. Fraudulent or otherwise deliberately manipulated anecdotal evidence, generally in the form of testimonials, is a time-honored method for increasing the plausibility and commercial viability of useless products. See also my discussion on anecdotal evidence .