Saint Alphosus Liguori
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Many of us know that the teachings of the Church on marital love are founded on the inseparable connection between the two meanings of the conjugal act: the unitive meaning and the procreative meaning (HV #12). Less well-known is that it took centuries and the teaching of several doctors of the Church for this foundational thought to develop. Saint Alphonsus Liguori (1696-1787) was one of them.

Liguori was a Catholic bishop who was canonized by Pope Gregory XVI and proclaimed a Doctor of the Church by Pope Pius IX. The Church celebrates his feast day tomorrow and it is fitting to recall Liguori’s part in the development of the meaning of sexual intercourse.

The Church Fathers

In the course of the Church’s history, there have been three purposes of sexual intercourse considered: procreation, the expression of conjugal friendship and fidelity, and the avoidance of concupiscence (sinful lust).

At the time of the Church Fathers, most agreed that the sexual act was for the procreation of children and that spouses should intend that whenever having relations. That seems a bit shocking to modern ears. But at the time this was a response to the out-of-control sexual permissiveness of the pagan Roman culture.

This was also the time of the Gnostic heresy, which proposed that all matter was evil. That included the human body, which meant procreation was evil because it brought another evil body into the world. In this environment, the Church held up that sexuality was not simply a plaything, but rather was for the serious and awesome purpose of giving new life. The Fathers acknowledged that it could also help remedy lust, but taught that spouses who intended only this purpose sinned.

St. Augustine

St. Augustine (354-430) also taught that sexual intercourse was for procreation and that spouses should intend procreation when they have intercourse. He did acknowledge that intercourse could be used as a remedy for lust, but taught that those who did this were guilty of venial sin. However, Augustine also indicated that marital relations can express friendship. This opinion pointed toward a development in seeing marital relations as an expression of fidelity.

Sts. Aquinas and Bonaventure

It was almost 1,000 years later when Sts. Thomas Aquinas and Bonaventure both taught that the marital act was for both conjugal fidelity and procreation. They believed that a man and wife could choose to express their friendship to one another through marital intercourse. Procreation was still clearly understood as one of the purposes, but spouses did not need to specifically intend this when they had relations. They could intend to express friendship. Importantly, these theologians maintained that the procreation could never be excluded, but it need not be explicitly intended. As for lust, Aquinas and Bonaventure both taught that taking a spouse out of selfish desire was wrong.

St. Alphonsus Liguori

Finally, in the eighteenth century, Alphonsus Liguori accepted both procreation and fidelity as the purposes of sexual intercourse. Not only that, he believed that as long as these two purposes were intended at least implicitly (not explicitly), there was nothing wrong in enjoying the pleasure of the sexual act. (Using a spouse only to satisfy lustful desires was still sinful.) So it was that Alphonsus Liguori united the two purposes of the marital act.

More developments in the theology of marriage have come through Casti Connubii, Humanae Vitae and the Theology of the Body, but these two foundational purposes of sexual intercourse remain.

To learn more, we recommend Is NFP Good? by Fathers Richard M. Hogan and John S. Levoir.

Is NFP Good?6for the serious and awesome purpose of giving new life. The marital act exists to give new life, and spouses should intend to give life when they have sexual intercourse. The Fathers acknowledged that intercourse also could be a remedy for concupiscence, but they also held that this purpose is selfish. They taught that spouses who intend only this purpose sin, at least venially.St AugustineSt Augustine (354-430), Bishop of Hippo, taught that marriage and sexual intercourse were for procreation. Spouses should intend procreation when they engage in the marital act. He realized that sexual intercourse could be used as a remedy for concupiscence, but he taught that spouses who did this were guilty of a venial sin. Augustine does indicate at one point that marital relations can express friendship, and so it seems that he does leave the door open to intercourse as an expression of fidelity. This development pointed to what was to come. Aquinas and BonaventureThe flowering of theology in the medieval period brought with it a development in the theology of marriage. In the thirteenth century, Thomas Aquinas and Bonaventure both taught that the marital act was for conjugal fidelity as well as for procreation. Spouses could choose to express their friendship to one another through the marital act. In other words, although procreation was clearly understood as one of the purposes of the marital act, spouses need not specifically intend this purpose when they engaged in sexual intercourse. They could intend to express friendship. Of course, these theologians maintained that the spouses could never exclude procreation, but they need not explicitly intend it. Recognizing that some thought the marital act was for the release of desire, Thomas Aquinas and Bonaventure taught that taking a spouse out of selfish desire was flawed. Alphonsus LiguoriFinally, in the eighteenth century, Alphonsus Liguori, accepting procreation and fidelity as the purposes of sexual intercourse, taught that it was not necessary for spouses to intend explicitly the good of procreation or fidelity. It was 7sufficient that they implicitly intended these purposes. As long as these two purposes were intended, at least implicitly, Alphonsus taught that there was nothing aberrant in enjoying the pleasure which accompanied the sexual act. Thus, Alphonsus Liguori united the two purposes of the marital act. Not only were both recognized as existing in reality (that had occurred in the medieval period), but now Alphonsus taught that both should exist in the intentional order at least implicitly.6Throughout history, magisterial documents and the theological research stimulated by them have tried to teach what the purposes of marriage are and what the spouses should include in their intention. The procreative purpose was recognized at the beginning. The conjugal friendship purpose came to be appreciated as the Church reflected on the mystery of the marital act. Intercourse as a remedy for concupiscence was recognized and criticized. From the beginning, the spouses were to intend the procreative purpose of the marital act. When the conjugal friendship purpose was recognized, it was clear that spouses could implicitly intend the procreative purpose and explicitly wish to express their friendship. The final development occurred when Alphonsus Liguori taught that both intentions need not be explicit, but it sufficed if they were implicit. Finally, the whole tradition holds that spouses who intend only the satisfaction of their own desires sins, at least venially