We have a saint!

The Scottish philosopher David Hume said: "no testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavours to establish". Thomas Hobbes put it a little differently and much less succinctly when he wrote "To understand therefore what is a miracle, we must first understand what works they are which men wonder at and call admirable. And there be but two things which make men wonder at any event: the one is if it be strange, that is to say, such as the like of it hath never or very rarely been produced; the other is if when it is produced, we cannot imagine it to have been done by natural means, but only by the immediate hand of God. But when we see some possible natural cause of it, how rarely soever the like has been done; or if the like have been often done, how impossible soever it be to imagine a natural means thereof, we no more wonder, nor esteem it for a miracle".

Miracles are a hot topic in Australia as I write this (in February 2010) because we have heard that the country is to get its first Catholic saint. Mary Mackillop will take the final step to sainthood on October 17 because she has now passed the final barrier – the acceptance of a second miracle attributed to her.

A brief biography of Mary Mackillop is probably in order here. Mary was born in Melbourne in 1842, the daughter of migrants who had managed to spend themselves into poverty. She worked as a teacher and governess and in 1866, together with Father Julian Woods, she opened the first free Catholic school in Australia and shortly afterwards founded the Congregation of the Sisters of St Joseph. By the time the Congregation had established 17 schools she fell out with the Catholic hierarchy (she was a little too independent for their liking) and was excommunicated. This lasted for about a year before she was reinstated, and she spent the rest of her life until 1909 in the service of education and the poor.

My feeling is that Mary did a whole lot of good work while she was alive and it is perfectly legitimate to honour her memory and celebrate her life. The fact that she did her good work because God told her to is irrelevant. Much of her biography suggests that she would have expressed her compassion in a productive manner without the church had she lived in a different period of history, and it devalues her life's work by setting up a situation where she is celebrated for performing (or more correctly, facilitating) miracles after she died.

Canonisation requires two accepted (I almost said "proven") miracles. The first miracle attributed to Mary Mackillop was a woman cured of leukaemia in 1961 after praying to Mary. The second miracle, which has just been accepted, was a woman who was diagnosed with inoperable cancer in 1993 but who was pronounced cured after carrying around a picture of Mary (attached to a piece of cloth from one of Mary's habits) for several months. Part of the problem with having this accepted as a miracle was getting doctors to declare that there was no possibility of a natural explanation. The doctors were following Hobbes – remission and unexplained cures had happened before, although rarely, and so this was just another case where science suspected that there was a natural cause but could not precisely identify it.

There are two ways that acceptance of miracles devalues science.

The first is the danger of encouraging people with serious illnesses to expect miracles to come from a deity rather than from reality. I have no problem with people praying for a cure as long as they don't give up their treatment while waiting for God to answer the prayers, but the publicity given to miracles could convince some people that prayer is a viable alternative to taking nasty medicine and undergoing uncomfortable procedures. As with quack cancer curers, a positive outcome is usually attributed to the alternative rather than any concurrent conventional treatment. The next step is "If prayer (or laetrile, or vitamin C, or …) works, why bother with the radiation and chemotherapy?".

The second point is that some people have tried to claim that the investigative process involved in canonisation is somehow scientific. It looks like science only in the way that there is a hypothesis (if you ask someone nicely and often enough they can persuade God to break the rules He set for the universe) and strenuous effort is made to refute any supposed supporting evidence. Real science would start after a miracle was established by trying to find out what really happened, but that next step is never taken.

For me, though, the whole procedure became much less fun after the position of Devil's Advocate was renamed to something more compliant with modern management principles. I would take a job in the Vatican myself if I could have that title on my business cards.

This article was published as the Naked Skeptic column in the April 2010 edition of Australasian Science