In his book Heretics, G. K. Chesterton writes,
There are some people — and I am one of them — who think that the most practical and important thing about a man is still his view of the universe. We think that for a landlady considering a lodger, it is important to know his income, but still more important to know his philosophy. We think that for a general about to fight an enemy, it is important to know the enemy’s numbers, but still more important to know the enemy’s philosophy. We think the question is not whether the theory of the cosmos affects matters, but whether in the long run, anything else affects them.Chesterton is making the point that one’s general system of values is an all-important factor in the choices he makes. For example, someone who subscribes to Ayn Rand’s “philosophy of selfishness,” or to Peter Singer’s judgment that infanticide is permissible because of utilitarian values, or to Christopher Hitchens’s view that religion is the most dangerous thing on earth, or to theologian Rev. Richard McBrien’s claim that popes have no authority in morals, can be expected to act in certain ways and take certain positions when confronted with choices. If we know their world view, we do not have 100 percent certainty about particular choices they might make under particular circumstances — but we do have high probability.
The Catholic analytic philosopher G. E. M. Anscombe (1919-2001), whose 1958 article “Modern Moral Philosophy” instigated new movements in “virtue ethics” and renewed interest in natural law, astonished her academic colleagues at Cambridge University in 1979 by publishing Contraception and Chastity, a defense of the Catholic Church’s position on contraception. Anscombe’s influence is still being felt in the United States via the Anscombe Society at Princeton University.
Analytic philosophy is famous for investigating logical connections, even in ethics, and Anscombe draws out the inescapable deductions that can be made from a value system accepting contraception:
If contraceptive intercourse is permissible, then what objection could there be after all to mutual masturbation, or copulation in vase indebito, sodomy, buggery, when normal copulation is impossible or inadvisable (or in any case, according to taste)? … But if such things are all right, it becomes perfectly impossible to see anything wrong with homosexual intercourse, for example. I am not saying: if you think contraception all right you will do these other things; not at all. The habit of respectability persists and old prejudices die hard. But I am saying: you will have no solid reason against these things. You will have no answer to someone who proclaims as many do that they are good too. You cannot point to the known fact that Christianity drew people out of the pagan world, always saying no to these things. Because, if you are defending contraception, you will have rejected Christian tradition…. For in contraceptive intercourse you intend to perform a sexual act which, if it has a chance of being fertile, you render infertile. Qua your intentional action, then, what you do is something intrinsically unapt for generation (emphasis added).In other words, Anscombe is saying that, if you believe you have a right to non-procreative sexual intercourse, you have no right to criticize non-procreative sex by others — for example, by a gay couple. You may justify your personal practices on the basis of your genuine mutual love and commitment to lifelong fidelity. But homosexuals may be even more intensely in love with each other and even more firmly committed to mutual fidelity. They may even be more open to procreation than you are, through adoption or through in vitro fertilization. To want to have sex without the possibility of offspring, and condemn others for similarly non-procreative sex, would be blatantly inconsistent.
A variety of objections to gay marriage have been offered. Some oppose it because it arbitrarily redefines marriage, or because it is not suitable for children to have gay parents, or because it will involve greater taxpayer burdens for Medicare and Social Security down the line, and so forth. But if we are part of that 80 percent of Catholics who are also involved in non-procreative sex, we cannot take the “high road” and be opposed to gay marriage because of “immorality.” At the very least, Catholics who choose artificial contraceptive methods, in the interests of consistency, should modify their opposition to gay marriage. If and when they follow the Church’s teaching on contraception, which has not changed over two thousand years and was reiterated by Pope Paul VI in Humanae Vitae, they will have a more secure moral justification for their opposition.