Viewed at the biological level, sex is a differentiation that occurs in animals of the higher types and renders each individual either male or female. The same hormones (in different proportions for male and female) are responsible for both the sex characteristics and the development of the spermatozoa and ova that together generate new life. In some lower animals, known as hermaphrodites, male and female characteristics can be exhibited by one and the same individual. In humans, the differences are determined at the time of fertilization and are recognizable, through life, by distinctive physiological, biochemical, and psychological features.
This article is not concerned primarily with the biology, psychology, or sociology of sex, but rather with its philosophy and theology as these are viewed by Catholics. It explains the sex urge in man, its peculiarly human character, its place in marriage, and its inseparable link to the procreation of the human race.
Sexual Urge. An unprejudiced analysis of the biological phenomenon of sex reveals its radical difference from other instincts. In man it is more an urge than an instinct since, although it arises in man without his conscious will, unlike animals he has the capacity to direct it. This is true of instincts such as hunger, thirst, and the need for sleep but there is a more comprehensive dimension to the sex urge. The fact that every human is either male or female, means that a person's whole being is oriented in a particular way within as well as outward to persons of the opposite sex. The need men and women have for each other shows that the sexual urge does not arise from the attraction of the sexes; rather, masculinity and femininity are for the sake of the sex urge. It is a manifestation of the contingent nature of the human person who can fulfill himself only through encountering another person (Wojtyła, Love and Responsibility, 45–49).
The normal sexual urge is always directed to a person of the opposite sex not just to the sexual attribute of the person. It is this personal dimension of the sexual urge, which provides the framework for love. The sexual urge is also supra-personal and has an existential value because it is the vehicle for prolonging the species (Wojtyła, Love and Responsibility, 51–53). The love that grows out of the sex urge is not purely biological or even psychological. It is given its defining form by acts of the will, which is the property of the person. Since each human person is sui iuris, that is, no one can will for him, it violates the person's nature to treat him simply as an object, especially a sexual object.
The total nature of sexual love is revealed in sexual ecstasy, which goes to the very depth of bodily existence. It has in its overwhelming power something extraordinary, to which terrible bodily pains are alone a counterpart. Apart from its depth, sex possesses an extraordinary intimacy. Every disclosure of sex is the revelation of something intimate and personal; it is the initiation of another into one's secret. In a sense, sex is the secret of each individual; it is for this reason that the domain of sex is also the sphere of shame in its most noble sense. This again explains the central position of sex in the human personality. It is a voice from the depths, the utterance of something central and of utmost significance. In and with sex, man in a special sense gives himself.
Complementarity and Conjugal Love. Man and woman have different and complementary parts to play in sexual intercourse. The man takes the initiative in response to the physical attraction of the woman. The woman, aroused by his caresses, surrenders to him, receiving him with his seed into herself. Both give and receive in the sex act. "Male sexuality is an emphasis on giving in a receiving sort of way, whereas female sexuality is an emphasis on receiving in a giving sort of way" (May, Marriage: The Rock on Which the Family Is Built, 26).
Because of these characteristics, sex is able to become an expression of conjugal love and to constitute an ultimate personal union. It is not only able to do so, but it is meant to become incorporated into this love; it is destined to serve the mutual self-donation to which spousal love aspires. Indeed, to understand the true nature of sex, its meaning, and its value, one must start with the glorious reality of the love between man and woman, the love of which the Vulgate says: "If a man gave all the substance of his house for love, he would despise it as nothing" (Sg 8.7).
Just as it is wrong to reduce all types of love to sex, as pansexualist psychologists attempt to do, so it is also erroneous to think that love between man and woman differs from other types of love only through its connection with sex. The specific quality of this love is apparent even before one takes note of the sexual urge.
It is true that spousal love can exist only between men and women. Yet man and woman are not only different biologically or physiologically—the sex hormones affect every cell of the human body—they are also different expressions of human nature. The specific feminine and masculine features of human personality show the same complementary character that is evident in sexual intercourse. Man and woman are spiritually ordered toward each other, being created for each other. They possess not a "fractional" complementarity as two halves of a whole but an asymmetrical or "integral sex complementarity," in which "the whole is always more than the sum of its parts" (see Allen, "Integral Sex Complementarity"). Each becomes more him or herself in the encounter with the other.
In this love, the beloved is more thematic than in any other love, becoming in fact the great human theme. Such a theme expresses itself also in the intentio unionis; although common to all categories of love, this assumes in man its highest tension and its furthest extension. The lover longs for union with the very being of the beloved; he longs for a common life, and the requital of his love assumes an incomparable importance.
Of this spousal and enamoured love Pope Pius XII said: "The charm exercised by human love has been for centuries the inspiring theme of admirable works of genius, in literature, in music, in the visual arts; a theme always old and always new, upon which the ages have embroidered, without ever exhausting it, the most elevated and poetic variations" (Address to newlyweds [Oct. 23, 1954] Pope Speaks, 21). Such love, aspiring to bodily union as a specific fulfillment of total union, is a unique, deep, and mutual self-donation. If someone loves another person with this love, he realizes fully the mystery of the bodily union and aspires to it simply because he loves the beloved.
Sex in Marriage. But one must also realize the tremendous commitment implied in this union. It is a self-donation that cannot be separated from marriage, from the will to enter into lasting union with the beloved. The will to be permanently united in marriage results organically from the very nature of spousal love. In sex man gives himself. The conjugal act involves so deep and radical a self-donation that it itself actualizes the indissoluble union to which spousal love aspires. The becoming "one flesh," of the very nature of this reciprocal gift, clearly presupposes not only love, but consensus, i.e., the solemn will of the spouses to bind themselves forever.
The role of sex in spousal love extends, however, much farther than the conjugal act. It manifests itself in the entire realm of intimacy granted to the spouses, in a symphony of effusions of tenderness culminating in this act. The fact that sexual desire often arises without being embedded in spousal love, and that sex can also, when isolated, exert a tremendous fascination, is no argument against its intrinsic relation to spousal love and to marriage. As a consequence of original sin, the sphere of sex can become a pure actualization of concupiscence and assume a completely different aspect. Yet the possibility of abuse and perversion of a thing in no way alters its true meaning and essence. For example, it is no proof against the mission, nature, and essence of man's intellect to grasp truth that many are attracted by intellectual activity as a mere display of dexterity or to satisfy pride. Similarly the tendency to isolate sex is no objection against its authentic mission and meaning.
Sex in Isolation. Sex possesses a tender, mysterious, and ineffably uniting quality only when it becomes the expression of something more ultimate, namely, wedded love. As soon as sex is isolated and sought for its own sake, its qualities are reversed. The depth, the seriousness, the mystery disappear, to make room for a fascinating, exciting, and befuddling charm that excludes anything beyond. Wherever sex is encountered in an unlawful form as a temptation, there is heard the siren song of lust, with its honeyed poison. The sublime joy of ultimate surrender—touching, chaste, intimate, and mysterious—that accompanies sex under other circumstances, is then completely absent. Sex is always extraordinary, but its characteristic extraordinariness assumes diametrically opposite forms. At one time, it is awe-inspiring, mysterious, noble, chaste, and free; at another, illegitimate, intoxicating, and befogging.
In sex, there is an element of promise, linked with a vague expectation of happiness. As long as this promise does not tend toward isolated satisfaction but remains in a reverent submission, awaiting its future as embedded in deep, spousal love, it itself is true. As soon as it is detached from such love—as when one expects the delights of paradise from sex as such—the promise becomes a treacherous one. Those who treat sex as the primary reality that can be understood in itself without recurring to spousal love thus fall prey to a fatal error. They are blind both to the nature of love and to the nature of sex. Ironically enough, in trying to reduce everything to sex, they fail to understand the nature of sex itself.
Sex and Revelation. This union, which is the sphere of such a sublime love as well as the conception of a new human person, Christ has raised to the level of a sacrament. The one-flesh union of Adam and Eve has been called the "primordial sacrament" because it made visible the destiny of man and woman to participate in divine Trinitarian communion—the mystery hidden from all ages. It was man's body that made visible invisible realities. The body in its masculinity and femininity possesses the nuptial attribute or the capacity for expressing love, which John Paul II calls the "nuptial meaning of the body." Even in his body man in some way images God. Man and woman image God alone but even more they image God as a communion of persons (John Paul II, The Theology of the Body, Feb. 20, 1980).
With the Fall, sacramental grace was lost. Separated from God, man became divided within himself and this disorder affected especially the sexual relationship. A tendency toward lust, toward treating the person of the opposite sex as an object of use instead of a "disinterested" gift, now distorts relations between men and women. Christ came to restore human nature. He not only called the human heart, where concupiscence arises, to conversion, but through His death and Resurrection He enabled its transformation through grace. The one-flesh union of marriage is once again an image of divine realities, the total self-giving love of Christ for His Church. This is the source and ultimate reason for its indissolubility. As a result of original sin concupiscence can be overcome only through grace and effort but man and woman are called to their original destiny of divine Trinitarian communion. Redemption, which brought this about, also made possible another way of living the nuptial meaning of the body, celibacy for the kingdom. It, too, is a spousal relation and points toward the resurrected state where there will be no marriage. Masculinity and femininity will remain as the basis for a new and perfect realization of interpersonal communion in our glorified bodies deriving from face-to-face communion with God (John Paul II, The Theology of the Body, Jan 13, 1982).
Sex and Procreation. To the sublime union of marriage God has confided the coming into being of a new man, a cooperation with His divine creativity. Such deep mystery calls for reverence and awe. It is no accident that God has invested an act of this kind with creative significance. As God's love is the creative principle in the universe, so love is everywhere creation. Thus there is profound significance in the nexus—at once symbol and reality—whereby, from the creative act in which two become one flesh, both from love and in love, a new human being proceeds. This mystery of the profound link between love and procreation sets forth the gravity of artificial birth control in a new light.
The capacity to generate life is intrinsically united to the sexual constitution of the human person. The encyclical Humanae vitae speaks of the inseparability of the unitive and procreative dimensions of sexual intercourse (Humanae vitae, no. 12). When a couple seek to unite and at the same time withhold their procreative powers during the fertile period, they are not "reading" the language of the body in truth. Conjugal love, which Paul VI describes as human, total, faithful, and exclusive, ceases to be total. When a couple, with serious reasons to postpone a pregnancy make use of the infertile times of the cycle for sexual intercourse they are doing nothing to impede the natural consequences of the act. Their love remains total.
Parenthood also rightfully belongs to marriage alone. Only those who have committed themselves totally to each other in marriage have made themselves fit to receive and to nurture life. Since they have given each other the identity of husband and wife, they are able to give the unconditional love necessary for the sustained care of offspring. Those who are not married have failed by their own choices to fit themselves to be parents.
Christian View of Sex. The Christian perceives the true mystery of sex; he perceives its depth, its seriousness, and its intimacy. He understands implicitly its ordination to serve the ultimate union in marriage, and the coming to be of a new human being. He is aware of the high value that it embodies as effecting mutual self-donation in wedded love, and as source of procreation. He clearly perceives the fearful profanation that every abuse of sex represents, the deadly poison defiling the soul and separating it from God; this is what sexual pleasure generates when treated as its own end. He shrinks from any contact with sex as soon as it is thus isolated and rendered poisonous. He possesses a deep reverence for its mystery, remaining at a respectful distance when not called by divine vocation to enter its domain. His is not a Puritanical or Manichean despisal of sex; for him, the conjugal act is neither something lowly, tolerated in marriage for the sake of procreation; nor is it merely a "normal" claim of the body finding in marriage its legitimate outlet.
The Christian understands that an ultimate interpenetration of sex and conjugal love takes place in mutual self-donation; sexual experience is thus not something parallel to love, but is absorbed and elevated by this love. Moreover, the Christian understands that sex belongs in a special manner to God, and that he may make such use of it only as explicitly sanctioned by Him. Only with God's express permission may he eat of the fruit of this tree. The awareness of this fact engenders a reverence that pervades his approach to sex even within the marriage bond. This enables him clearly to understand the sinfulness of artificial birth control, with its irreverent severing of the deep link between the ultimate love union and procreation. He understands the tremendous dignity with which the conjugal act is endowed by marriage's being a Sacrament. This implies that his very love calls for being transformed in Christ. He is aware of the fact that only in Christ and through Christ can he live up to the full glory and depth to which this love by its very nature aspires. As Pius XII has stated:
But what new and unutterable beauty is added to this love of two human hearts, when its song is harmonized with the hymn of two souls vibrating with supernatural life! Here, too, there is a mutual exchange of gifts; and then … through natural affection and its impulses, through a spiritual union and its delights, the two beings who love each other identify themselves in all that is most intimate in them, from the unshaken depths of their beliefs to the highest summit of their hopes. [Ibid. ].
See Also: chastity; continence; modesty; virginity
Bibliography: d. von hildebrand, In Defense of Purity (New York 1931; repr. Baltimore 1962). w. e. may, Marriage: The Rock on Which the Family Is Built (San Francisco 1995). john paul ii, The Theology of the Body: Human Love in the Divine Plan (Boston 1997); Familiaris Consortio. paul vi, Humanae Vitae. p. m. quay, The Christian Meaning of Human Sexuality (Evanston, Ill.1985). m. shivanandan, Crossing the Threshold of Love: A New Vision of Marriage in the Light of John Paul II's Anthropology (Washington, D.C. 1999). k. wojtyŁa, Love and Responsibility (San Francisco 1981). p. allen, "Integral Sex Complementarity and the Theology of Communion," Communio 17 (Winter 1990) 523–544.
[d. von hildebrand/