There are three interesting facts about Lourdes (or any other miracle healing phenomenon for that matter) which taken together make claims of miracles unreliable and, as we shall we see, ultimately illogical and untenable.
1. The number of sick people who've gone to Lourdes is much larger than the number who claim to have been healed. Since 1858 an estimated 2 million have made the pilgrimage. The number of claimed miracles on the other hand hovers at around 6,000 [Hines, p.348]. The ratio of claimed healings to the number of sick is therefore 6,000 / 2,000,000 = 0.003 or a third of a percent. This translates to 3 positive testimonials for every 1,000. This is a very small number. Assuming for a moment that those who claim to have been healed were in fact cured, the rate of failure of Lourdes is a staggering 99.7%. As a way of assimilating this, ask yourself if you would enthusiastically spend some USD3,000.00 (an off-the-top-of-my-head estimate of the cost of a Lourdes pilgrimage) to undergo a medical treatment that advertised a success rate of 0.3%.
2. If a third of percent doesn't dissuade you, the truth is the figure is much worse. You see, testimonials are not accepted at face value by the Church, for very good reasons. All claims are first scrutinized and investigated by the Lourdes Medical Bureau "to rule out trickery, acting, illusion, a possible hysterical or delirious pathology." When a claim passes the preliminary screening the case is handed over to the International Medical Committee of Lourdes (CMIL) which is composed of Catholic doctors from various European countries. It is CMIL that determines whether a case of healing is in fact medically inexplicable. However, the final say as to whether the said case is a miracle or not rests upon the Church. [Hines, p.348] So how many claims has the Church certified as miracles? A mere 67. Thus, out of the 6,000 claims only 67 have been able to pass through the eye of the needle. If we now take this as the definitive number of miracles, the success rate of Lourdes is in fact 67 / 2,000,000 = 0.00335%. In other words Lourdes has a failure rate of 99.996665%. (I didn't even dare round it off to 2 decimal places!)
Imagine the following: 30,000 people with a certain disease have been invited to try a drug. You are one of them. You're told that only one of the 30,000 will benefit from the drug, and that to become part of the program you need to pay a fee of USD3,000.00. And no, you don't get a refund if you're amongst the 29,999 who go home still sick. Those are the odds at Lourdes: 1 in 30,000.
3. If you think it can't get any worse than that, you better pop an antacid. Among those who've been miraculously healed in Lourdes is a young woman who had Budd-Chiari syndrome, a condition wherein the veins of the liver become blocked. In 1963 she was certified as having had a miraculous healing. There's a slight problem though. She eventually died of Budd-Chiari seven years later. What happened to the miracle? CMIL admitted that "when they reached their decision [that the woman had had a miracle cure] they were insufficiently aware of the natural history of Budd-Chiari syndrome and the possibility of natural remission." [Hines, p. 349-350] Bottom line: the determination of miracles is hardly foolproof and error-free.
CMIL is quite cognizant of the fact that medical and scientific knowledge advances such that what is currently inexplicable may not be so in the future, as implied in their of use of qualifiers/caveats as "in the present state of scientific knowledge." Rev. Peter Gumpel is "an official at the Vatican's Congregation for the Causes of the Saints, which investigates reports of miracles by candidates for sainthood." He echoes the CMIL's understanding of the cumulative and progressive nature of scientific understanding, admitting that,
What seems like a miracle now may not be one in a hundred years. Such are the advances of science. Declarations of miracles are not infallible teachings.We simply don't know all there is to know about the human body and disease, even as we have made great strides.
The mere fact that we currently don't understand X or cannot explain X does not at all imply that it's a miracle. It would be fallacious to say it is.
We can't explain X.The contradiction is easy to see if we make explicit the fact that we don't yet know and understand everything about the natural world.
We conclude that X is supernatural.
But this implies that we know what X is.
We are not omniscient.Since the premise that we are not omniscient is evidently true then it must be that our inference "X is supernatural" is unwarranted. Just to further show why it is unwarranted: Given an X which eludes explanation, rather than pointing to the supernatural we can just as well say that X is extraterrestrial in nature, that an advanced and very benevolent civilization has caused the cure. The supernatural is just one hypothesis among hypotheses. Our inability to explain something is not evidence for our favored hypothesis. Rather, our inability to explain merely expresses our ignorance of the explanation.
We cannot explain X
Therefore, X is supernatural.
This implies that we have ruled out all natural explanations.
But this means we are omniscient.
So why does the Church make the unwarranted conclusion? Why does the Church not stop at what is indubitably and medically accepted as true--that X is currently inexplicable, that given our present understanding the healing cannot yet be explained? Whatever its reason, and given CMIL's lucidity on the matter and Gumpel's admission, the certification and declaration of any unexplained cure or remission as miraculous--i.e., that it is supernatural in nature--is an act of hubris.
In conclusion, even with 67 certified miracles, these are not known to be in fact miracles, but rather simply declared as such. The Church arrives at its conclusion via a version of an argumentum ad ignorantiam whereby they take the current lack of natural explanations as license to call the event supernatural. This as we have seen is overtly fallacious. If, as Gumpel rightly says, a hundred years from now medical science is able to explain any or all of these 67 cases then they will lose their "miracleness," which is just saying that they were not miracles in the first place.
Terence Hines. Pseudoscience and the Paranormal, 2nd ed. Prometheus Books. 2003.