So far it has not received much media attention, being drowned out by the various scandals swirling around the Obama administration, but in May the California Assembly passed a bill, AB-460, requiring insurance companies to provide infertility treatment to same-sex couples. The bill was introduced in February and is now awaiting discussion in committee in the Senate. Arguing that since health insurance already covers infertility treatment, including artificial reproductive technologies such as artificial insemination (although not in vitro fertilization), for opposite-sex couples, equality demands that the same coverage be extended to same-sex couples. Whatever one’s views on homosexuality and same-sex marriage, AB-460 illustrates the complex and contradictory views on sexuality, marriage, and children present in our society. Even if this bill has so far avoided the limelight, with the increasing acceptance of same-sex marriage and the Supreme Court’s two upcoming decisions on the issue (Hollingsworth v. Perry and United States v. Windsor), we as a church and a nation will not be able to avoid a discussion of how we understand the relationship between marriage and procreation.

The debate over same-sex marriage revolves around the proper definition of marriage. Arguments that marriage should be limited to partners of the opposite sex almost always hinge on the procreation of children being a defining characteristic of marriage. For example, in their document Between Man and Woman, the U.S. Catholic bishops write, “Only a union of male and female can express the sexual complementarity willed by God for marriage. The permanent and exclusive commitment of marriage is the necessary context for the expression of sexual love intended by God both to serve the transmission of human life and to build up the bond between husband and wife” (emphasis mine). In contrast, the Human Rights Campaign, in a brief question and answer guide, defines marriage as “the highest possible commitment that can be made between two adults.” Here the focus is exclusively on the couple’s relationship, and not on the procreation of children.

One of the most common arguments against official Catholic teaching on marriage and homosexuality is that it is inconsistent. On the one hand, because the sexual acts of a same-sex couple are non-procreative, then their relationship is not fitting for marriage. On the other hand, the Catholic Church permits couples in which one or both of the persons are infertile to get married, as well as couples in which the woman is past the age of menopause, even though the sexual acts of these couples are also unavoidably non-procreative. The response that these latter two cases are different from a same-sex couple because they include a man and a woman seems a bit circular, since the necessity of the couple including a man and woman is predicated on its being procreative.

The Catholic position, however, depends on Aristotelian metaphysics. As many probably know, for any substance, or individual thing (e.g., a guitar), Aristotle claims that it possesses a form, those properties that make the thing what it is (guitar-ness), and matter, the particular material out of which a thing is made or in which it is embodied (wood, bronze for the strings, etc.). Aristotle also distinguishes between the substance, that which is essential to what the thing is (guitar), and the accidents, or incidental features of the thing that perhaps distinguish it from other similar things but have no bearing on what it in fact is (brown, 6 lbs., etc.). Finally, Aristotle concludes that every substance contains the potentiality to attain certain ends (playing music), and that either through some internal dynamism or when acted upon by something else (a guitar player), that potentiality is actualized. Nevertheless, a thing can be thwarted in the actualization of its potentiality, for example by a defect in its matter (e.g., a broken guitar).

These concepts from Aristotelian metaphysics are crucial for a proper understanding of official Catholic teaching on homosexuality (and a host of other issues as well: for example, this is why Catholic teaching insists that a fetus is a “person” and never refers to it as a “potential person,” because a thing’s identity is defined by its potentiality rather than its actualization). A union of a man and a woman is a particular type of “substance,” and one of the ends of this union, the procreation of children, is actualized through a sexual act. In situations where the couple is post-menopausal or infertile, however, this end cannot be actualized because of an “accidental” condition, whether through the natural development of a woman’s reproductive system in menopause or to a defect in the man or woman’s reproductive system in infertility. A same-sex couple, on the other hand, is non-procreative not because of an accidental condition, but because of the very nature of the relationship, just as it is not a defect that a broom does not make music, but rather is precisely because it is not a guitar (or other type of musical instrument). Therefore, according to this logic, marriage can rightly be limited to a man and a woman even in cases where only one of the ends of the marriage (conjugal love) can be achieved, and the other (the procreation of children) cannot, while excluding relationships between two people of the same sex, because the former possesses a form that the latter does not.

The point here is simply to show the internal consistency of the official Catholic position, not its correctness; after all, the argument already presupposes that the procreation of children is essential to the “substance” of marriage. Arguments in favor of same-sex marriage, even within the Christian tradition, would simply reject this understanding of marriage. For example, Catholic theologians Todd Salzman and Michael Lawler push toward understanding marriage more exclusively in terms of its unitive end (i.e., conjugal love), and drawing on the scientific understanding of same-sex attraction and sexual orientation, argue that lesbian and gay couples experience a distinct type of complementarity that nevertheless can generate the bond necessary for marriage. Anglican theologian John Milbank makes a quite different argument, claiming that same-sex couples exhibit a “logic” distinct from the procreative complementarity proper to marriage that nevertheless serves real personal and social goods. What one cannot argue, however, is that same-sex relationships have an innate biological potentiality for procreation.

Yet this is precisely what the proposed law in the California legislature seems to be suggesting by mandating that health insurance pay for infertility treatment for same-sex couples. Health insurance typically distinguishes between services that meet real health needs, defined in terms of restoring normal functioning or appearance, and services that are more cosmetic (there are echoes here of Aristotle’s distinction between substance and accident!); the latter are almost always excluded from coverage, while the former are covered or not based on the conditions of the policy. Breast augmentation is a classic example illustrating the difference; if the procedure is done simply to look more appealing in one’s own eyes or the eyes of others, then it would be considered cosmetic surgery and generally not be covered by insurance, whereas if the procedure is performed as part of a breast reconstruction after a mastectomy, for example, then the goal is to restore, rather than enhance, “normal” appearance, and therefore the procedure could possibly be covered by insurance. For an opposite-sex couple, infertility is clearly an impairment of normal biological function, and therefore might appropriately be covered by insurance (and in fact California law already mandates coverage of infertility treatments). For a same-sex couple, on the other hand, it is not clear what health condition is being treated. The bill does not require either individual to have been diagnosed with infertility. Although “the presence of a demonstrated condition recognized by a licensed physician and surgeon as a cause of infertility” is listed as one of the recognized definitions of “infertility,” so is “the inability to conceive a pregnancy or to carry a pregnancy to a live birth after a year or more of regular sexual relations without contraception.” This latter definition makes sense in the context of an opposite-sex couple, but for a same-sex couple this simply describes the natural outcome of a sexual relationship! The bill, while quite explicitly proposed to promote the equality of same-sex couples, suggests that what is normal and inevitable for a same-sex couple is the equivalent of impaired health for an opposite-sex couple.

The Bill Analysis provided by the legislature makes explicit the important point that the bill considers infertility a condition of the couple as a unit. It states, “Under the current definition of infertility heterosexual married couples are typically treated as a unit for infertility. If a husband has a low or no sperm count, both the husband and wife are diagnosed with primary male factor infertility because the spouse does not produce the gamete needed for conception. Assisted reproductive technology is used to attain a pregnancy where the wife is ultimately a patient regardless of her female fertility status.” The point here is that even if infertility is caused by a condition suffered by the man, the woman can be artificially inseminated and still be covered by her insurance, because the condition is ascribed to the couple as a unit. By analogy, then, a woman in a lesbian relationship who herself does not suffer from infertility could also have artificial insemination covered because, considered as a unit, her relationship is infertile. What is remarkable about this argument is that it assumes that the procreation of children is part of the normal functioning of a sexual relationship (a “unit”), and that therefore even the natural functioning of a same-sex relationship falls short of the ideal.

One often hears the argument (which I myself have made) that the push for same-sex marriage merely reflects a gradual shift in the meaning of marriage, taking place over the course of decades, where the institution is seen primarily as a means of personal fulfillment for the couple, and only secondarily if at all an institution for the raising of children. Whatever else it is, California’s proposed bill is evidence that this narrative is too simple. Perhaps the connection between marriage and children really is deep-seated, even for such a staunch advocate for gay and lesbian rights as Tom Ammiano, the author of the bill. This connection between marriage and children could serve as a basis for civil discussion, if not common ground, between opposing sides whose treatment of one another has tended toward the vitriolic. Supporters of same-sex marriage should reject the conclusion of Judge Vaughn Walker, who threw out California’s Proposition 8 in 2010, that any effort to define marriage as between a man and a woman “fails to advance any rational basis.” Having recognized that there is some intrinsic connection between sexual relationships and procreation, and that opposite-sex and same-sex couples differ in their ability to achieve that end, they should at least admit that the opposing view is plausible. And opponents of same-sex marriage should listen to same-sex couples’ experiences of longing for children as something flowing from their relationship, raising the possibility that the good of procreation could be fulfilled through adoption or artificial reproductive technologies. Ironically, a bill that is in many ways quite paradoxical could contribute to greater understanding in the same-sex marriage debate. Regardless of how the Supreme Court decides in the two upcoming cases concerning same-sex marriage, we as a nation will be having a conversation on the relationship between marriage and procreation sooner rather than later, so better understanding of one another will be more important than ever.