Advocates of same-sex “marriage” commonly assert that its opponents are intolerant bigots unjustly denying a fundamental human right to individuals attracted to persons of the same sex. They maintain that same-sex couples can live in a committed relationship and have a right to express their affection for one another. Many such couples claim that they cannot satisfy their sexual urges and natural inclination toward intimate union in any more adequate way than by establishing a more or less permanent relationship that includes sexual intimacy. They point out that the actual capacity to generate children is not necessary for a valid marriage; after all, opponents of same-sex marriage readily grant the validity of the marriages of men and women known to be sterile and hence incapable of having children, so why can they not recognize the validity of the marriages of same-sex couples who love each other and wish to share their lives as spouses? It is imperative to offer intelligent replies to the challenge these considerations pose, and I hope to do so here. I will first contrast marriage and the marital act with same-sex unions and homosexual acts and then offer an argument to show why same-sex unions simply cannot be regarded as marriages. Marriage and the marital act vs. same-sex unions and homosexual acts Marriage is not a merely instrumental good, in the service either of procreation, as St. Augustine thought, or of pleasure, as same-sex advocates such as Steven Macedo maintain. It is rather a fundamental or basic good of human persons precisely as males and females, and because it is it offers married men and women a reason to engage in the marital act. Vatican Council II indicated this great truth when it declared: “God did not create the human person as a solitary,” and after citing “male and female he created them” (Gn 1.27) explains that the two sexes' “companionship produces the primary form of interpersonal communion. For, by their innermost nature human beings are social, and unless they relate themselves to one another they can neither live nor develop their gifts.” Commenting on this passage, Germain Grisez notes: “This gloss on Gn 1.27 implies that marriage is not merely an instrumental good: the companionship of man and woman belongs to humankind as image of God and is the primary form of one of the essential, intrinsic aspects of human fulfillment. Marriage is consummated by the marital act, which is far more than a genital act between a man and a woman who happen to be married. Men and women are capable of having genital sex because they have genitals, and thus fornicators and adulterers are able to have genital sex. But fornicators and adulterers are not capable of engaging in the conjugal or marital act precisely because they are not married, and it is marriage that capacitates spouses to engage in the marital act, i.e., to do what spouses are supposed to do, to become literally one flesh in an act whereby the man personally gives himself to his wife by entering into her body person, and in doing so receives her and whereby the woman personally receives her husband into her body person and by doing so gives herself to him. The marital act moreover is the kind or type of act intrinsically fit or apt both for communicating conjugal love and for receiving the gift of life. This act is and remains a procreative or reproductive kind of act even if the spouses, because of non-behavioral factors over which they have no control, for example, the temporary or permanent sterility of one of the spouses, are not able to generate human life in a freely chosen marital act. Their act remains the kind of bodily act that alone is “apt” for generating human life. In the marital act, moreover, the bodies of both husband and wife are not used as instruments to provide them with subjective states of consciousness but rather as components intrinsic to themselves as bodily persons. When one treats one's body as intrinsic to one's self, there is a unitary activity, and various bodily actions share in this activity since they are not directed to an extrinsic purpose. In activity of this kind, as Finnis says, the body's “activity is as much the constitutive subject of what one does as one's act of choice is.” Thus in the marital act, spouses freely choose to instantiate their communion of persons in one flesh open to the gift of life in and through an act in which their bodily activity is as much the constitutive subject of what they are doing as is their act of choice. How different from this are same-sex unions and homosexual acts. Homosexual acts in the strict sense are anal or oral intercourse willingly engaged in by two males, with the intention that at least one of them achieve satisfaction by ejaculating within the other's body. Such acts are acts of sodomy or homosexual intercourse. A lesbian couple can, without engaging in intercourse, stimulate each other to orgasm, and such intentional acts can also be regarded as homosexual in a broader sense. And both male and female homosexuals may choose to masturbate each other as ways of expressing their affection. But are such acts truly “appropriate” means to do so? Before giving a moral analysis of these acts it seems to me helpful to describe in the physiology of one specific homosexual act, namely, anal intercourse, the sine qua non for many male homosexuals. However, human physiology, as John R. Diggs, Jr., M.D., points out, “makes it clear that the body was not designed to accommodate this activity. The rectum is significantly different from the vagina with regard to suitability for penetration by a penis. …the anus is a delicate mechanism of small muscles that comprise an ‘exit-only' passage. With repeated trauma, friction, and stretching, the sphincter loses its tone and its ability to maintain a tight seal. Consequently, anal intercourse leads to leakage of fecal material that can easily become chronic. … The list of diseases found with extraordinary frequency among male homosexual practitioners as a result of anal intercourse is alarming: anal cancer, chlamydia trachomatis, cryptosporidium, giardia lamblia, herpes simplex virus, human immunodeficiency virus, human papilloma virus, isospora belli, microsporidia, gonorrhea, viral hepatitis type B & C, syphilis.” This passage gives reasons to think that anal sex is hardly an appropriate way to express friendship. But even prescinding from these deleterious consequences we can show how harmful homosexual acts are to the persons choosing to engage in them. In sodomitical and other kinds of homosexual behavior the bodily joining of the persons of the same sex does not unite them as one complete reproductive organism. Although they may choose such acts as means of experiencing personal intimacy, the resulting experience cannot be the experience of any real unity between them. Rather, “each one's experience of intimacy is private and incommunicable, and no more a common good than is the mere experience of sexual arousal and orgasm. Therefore, the choice to engage in sodomy for the sake of that experience of intimacy in no way contributes to the partners' real common good as committed friends.” Persons choosing homosexual acts use their own and each other's bodies to provide subjective satisfactions, states of consciousness. Thus the body becomes an instrument used and the conscious subject the user. The conscious self is alienated from the body. To choose to engage in homosexual acts is to choose a specific kind of self-disintegrity. The self-integration damaged in this way is the unity of the acting person as conscious subject and sexually functioning body. But, as Grisez points out, “this specific aspect of self-integration…is precisely the aspect necessary so that the bodily union of sexual intercourse will be a communion of persons, as marital intercourse is.” Therefore, homosexual acts damage “the body's capacity for the marital act as an act of self-giving which constitutes a communion of bodily persons,” or in other words, the “nuptial meaning of the body.” An Argument Against Same-Sex Marriage

Persons of the same sex cannot marry because they cannot do what married couples can do, i.e., to consummate their union by a bodily act in which they become the common subjects of an act that, precisely as human behavior, is eminently fit both for the communication of spousal love and for the generation of new human life. Genital coition is the only bodily act intrinsically capable of generating new human life. Our society, as any society, can survive only if new human persons are generated. The marital union of a man and a woman who have given themselves unreservedly in marriage and who can consummate their union in a beautiful bodily act of conjugal intercourse is the best place to serve as a “home” for new human life, as the “place” where this life can take root and grow in love and service to others. A marriage of this kind contributes uniquely to the common good. It merits legal protection; same-sex unions are not the same and sadly merely mimic the real thing. They can in no way be regarded as marriages in the true sense.