With the Illinois legislature poised to consider a bill to legalize same-sex marriage, Chicago's Cardinal Francis George officially entered the political fray by issuing a letter that urges Catholics to urge their representatives to oppose the legislation. The core of George's argument was straightforward: "Civil laws that establish 'same-sex marriage' create a legal fiction," he wrote, because the "State has no power to create something that nature tells us is impossible."
Really? "Impossible"? Where, exactly, does "nature" tell us that? Does "nature" speak directly to Cardinal George? More likely, George got his information from Saint Thomas Aquinas, who communed with "nature" 750 years ago. In his prodigious Summa Theologica, Thomas largely rewrote much of Christian moral theology and provided a rationale in "nature" for the notion that same-sex sex is contemptible in the sight of God.
Thomas posited that God had instituted the order of nature by which everything was fittingly directed to its proper end; that God had created "natural" coitus for the sole purpose of procreation; that man should not contravene the order of nature; and that man therefore should not engage in any sexual act that is not directed to procreation.
Thomas defined luxuria as the sin of excess in sexual pleasures. There is no sin in sexual things as such, he explained, as long as they are undertaken for the proper purpose (reproduction) and in the proper manner (sexual intercourse in the missionary position).
Thomas divided luxuria into six separate acts: simple fornication, adultery, incest, deflowering a virgin, rape, and vice against nature. Although the first five are mortal sins, they are not as serious as the vice against nature, because they involve "natural" coitus (ejaculating into a vagina). Sins against nature are more serious, because they are an affront to God.
Thomas identified four sins against nature: (1) masturbation, (2) sex with a person of the opposite sex other than in the "natural" manner (i.e., with the man on top), (3) sex with someone of the same sex, and (4) bestiality.
Central to Thomas's classification system was the concept of "unnatural" acts. For Thomas, the key determinant was whether the act was intended to result in procreation. His definition of "natural" was premised on an assumption about the purpose of the genitals, and he inferred this purpose from the behavior of animals.
There are several interesting gaps in this reasoning. First, the declaration of purpose is arbitrary. There is no reason why the purpose of the genitals might not also be to give pleasure for pleasure's sake. It is not a mortal sin for a man to walk on his hands, even though that is not their "purpose."
Second, the definition of "natural" is strained. As Saint Jerome observed, sexual desire is "innate" in humans, and to remain chaste requires one to "act against nature." The term "natural," in other words, is plastic.
Third, Thomas's assumption about animal behavior was erroneous. Some animals masturbate, most do not use the missionary position, few are monogamous, and some, like the hyena, the hare, and the weasel, engage in same-sex behavior (facts that were well-known at the time).
Fourth, it is surprising that Thomas would declare animal behavior the model for human behavior, particularly because "unnatural" acts were condemned as brutish and animalistic. Moreover, in every other context Christian theologians, Thomas included, emphasized that man is not like the animals.
Finally, Thomas's scheme left unanswered some awkward questions. For example, may a woman who is past menopause have sex?
The plain and simple fact is that reasoning about what is "natural" is deeply vulnerable to distortion by one's own personal values and preferences. Cardinal George insists that same-sex marriage is incompatible with "nature." One might just as easily say the same about celibacy. There is such a thing as right and wrong, but invocations of what "nature" commands is no way to get there.
If Cardinal George wants to invoke the law of "nature," then perhaps he should invoke Jesus: "Do unto others as you would have them do unto you." (Matthew 7:12; Luke 6:31). This precept, which is found in one form or another is virtually every religious and ethical tradition, is a pretty good law of "nature." Apply that one to the issue of same-sex marriage.