A great controversy in the history of moral theology was the concept that a doubtful law could not bind. The logic was simple: you can only be bound by a law which you know to be true and truly applied. If there is more than one reputable view of the question, we are entitled to choose which opinion to follow. This was, and is, called Probabilism. Its opposite was Probabiliorism. This held that one was obliged to choose the more probable opinion. A third view was Tutiorism, which held that we must always take the safest way however small the likelihood of it being binding.
While Tutiorism seems to have been a minor movement, great arguments took place between Probabilism and Probabiliorism. And each fell in and out of fashion. One of the more robust moments was the attack on Probabilism (as the Jesuit theologians interpreted the principle) in Pascal’s Lettres Provinciales – which remains one of the great books of religious controversy. He accused them of teaching that any opinion held by one of their theologians constituted sufficient doubt to negate the law. And went on to say that they encouraged diversity of opinion since you could always find at least one authority teaching what you wanted to hear.
Nowadays Probabilism is the only horse in the race, although the opinion one may follow needs to be “solidly probable”. The best case study known to me is Canon McReavy’s consideration of the moral law on contraception in the Clergy Review, September 1967. That was, you may recall, after the Birth Control Commission had finished but before Paul V1th had given his decision.
McReavy showed clearly the strength and the range of the opposition to the traditional position. One prominent example was the Dutch Catechism which urged couples to form their consciences in the light of the general values of marriage as laid out in Vatican II. However, he decided that Paul VI’s messages, urging that the traditional position should be observed until his final view could be given, removed the question from the table for the time being. So he concluded – not necessarily correctly in my view – that it didn’t pass the test.
Pascal’s book is well worth at least dipping into. Easiest to find a translation by looking up Lettres Provinciales in Wiki. One example which I liked was the idea that, if involved in a duel, one would do well to kill one’s opponent by stealth beforehand. In that way one would avoid risking one’s life and participating in one’s opponent’s sin committed by duelling. But that is just one of many, many examples.
One might apply Probabilism to the much contested opinion that one may use a condom to protect one’s married partner from HIV – on the grounds that the act is not one of contraception but protection. This is an issue involving strong theological doubt. The Vatican appears to have deliberately avoided answering the question. (The Pope’s recent remarks on condom use for protection are clearly not directed at married couples, and so do not touch the issue.) Do you think that the opinion that a condom may be rightly used in marriage for protective purposes is a solidly probable one? Or is it just a Jesuitical way of talking oneself out of a difficulty?
Writing of which, as I live in a Jesuit parish I like to mutter about the Lettres Provinciales just to annoy. And if that doesn’t make them blench, I throw in the question of owning and selling slaves in Maryland for two hundred years, and well into the 19th century.
(By the way, the excuse that one had to write a long letter because one did not have the time to write a short one comes from Lettres Provinciales. It did not originate with Bernard Shaw, as is often suggested.)