Lonergan on Contraception, Part I

In September 1968, the Canadian Jesuit philosopher and theologian Bernard Lonergan wrote a letter to another priest in which he explained why the official church teaching about contraception cannot accurately be said to have been derived from natural law. As he points out in the conclusion of the letter, "when there is no valid reason whatever for a precept, that precept is not of natural law" (9).

His refutation of the argument from natural law is brilliant, but some people have difficulty with some of the philosophical terminology. Below are several passages from the letter. Following each one is an explanation that can be understood, I hope, by those without an academic background in philosophy.

Lonergan begins the letter by noting

"that traditional Catholic doctrine on the sexual act followed rigorously from the position adopted by Aristotle in his De generatione animalium. That position was that the seed of the male was an instrumental cause that changed the matter supplied by the female into a sentient being...The efficient causality of the male was needed to produce the sensitive principle or soul. On that basis it was clear that every act of insemination was of itself procreative and that any positive interference was an act of obstructing the seed in its exercise of its efficient causality." (8)

The important thing to understand here is that Aristotle saw the relationship between insemination and conception as simply one of cause-and-effect. Catholic theolgians shared this view and decided that anything that hinders the cause from achieving its intended effect is unacceptable: if God intends that this cause should have that effect, it is wrong to prevent the effect from taking place.

"Two factors, however, have combined to bring about a notable change in the views of Catholic theologians on this matter. The first, of course, is the fact that the Aristotelian position is erroneous. Insemination and conception are known now to be quite distinct. The act of inseminating is not an act of procreating in the sense that of itself, per se, it leads to conception. The relation of insemination to conception is just statistical and, far more frequently than not, insemination does not lead to conception" (8).

It seems odd that people should not have seen reproduction this way sooner, given that most acts of insemination clearly do not lead to a conception. These should have been seen as distinct events, simply because the latter only occasionally follows the former. At any rate, the recognition that the relationship between insemination and conception is statistical has replaced the view that insemination is procreative in and of itself.

"So there arises the question whether this statistical relationship of insemination to conception is sacrosanct and inviolable. Is it such that no matter what the circumstances, the motives, the needs, any deliberate modification of the statistical relationship must always be prohibited?" (8).

Lonergan is asking if it there are any circumstances in which one can do something to change the statistical probability of conception taking place.

"If one answers affirmatively, he is condemning the rhythm method. If negatively, he permits contraceptives in some cases. Like the diaphragm and the pill, the menstrual chart and the thermometer directly intend to modify the statistical relationship nature places between insemination and conception" (8).

This is, I would argue, the crux of the problem, and the failure to recognise this is one of the main reasons why contraception is still being debated in the church. Supporters of the ban on contraception were deprived of the one reasonable argument they could possibly have made by the allowance of "natural family planning." So they argue unreasonably, applying made-up moral principles and concocting all varieties of fallacious arguments. But that is a subject for another day.

In the next post I will look at the second factor, alluded to above, that has brought about a change in Catholic thinking on this matter.

Go to Part II

The quotations are from a letter dated September 6, 1968, and published in the Lonergan Studies Newsletter 11 (1990): 8-9. That newsletter can be read in pdf format here. Just scroll down to page 8 to find the letter.