Lourdes effect

The term Lourdes effect has been coined by the Belgian philosopher and skeptic Etienne Vermeersch for the tendency of supposed supernatural powers to resist clear demonstration. Vermeersch suggests that, if the miraculous healing powers of Lourdes are real, one would expect the Virgin Mary or God to reattach a severed arm as often as more ambiguous cures of paralysis or blindness; and that the lack of such undeniable healings is strong evidence against the subtle ones as well. The same applies to other mysterious and occult phenomena such as the sightings and photos of the Loch Ness Monster and the Yeti.

Vermeersch uses this term to mock what he calls the selective and uncritical approach to miracles, or the frivolous attribution of supernatural gifts to human beings. Skeptics note that the number of fatal accidents that occur on the way to and from Lourdes may well be considerably higher than the 67 alleged miracles due to faith healing recognized in 2005 by the Vatican.