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 (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.