The need for renewal in Catholic moral theology is indicated not only by the limitations of the older moral theology. Substantial opportunities for ecumenism and evangelization also call for renewal in Catholic moral life and the moral teaching which guides it.

Almost from the beginning, Christian moral thought has been impeded by an unresolved, underlying tension between the supernatural and the natural, between the sacred and the secular. Before Christianity, neither Jews nor pagans sharply distinguished these domains. The gospel introduces a new and sharp distinction: Birth as a human person is distinguished from rebirth as a child of God; flesh is distinguished from Spirit; the things of Caesar are distinguished from the things of God.

In the Christian thought of the Middle Ages, this essential distinction—which in itself clearly is divinely revealed—tended to develop into a separation and even into an opposition between nature and grace. Catholic thought resisted this tendency in many ways, for example, by the doctrine and practice of the sacraments, which unite earthly with heavenly things. Also, the Catholic ideal of society was not one of separation and opposition between Church and state. Still, a strong tendency persisted to regard the pursuit of human goods in this world as an activity in itself pointless. St. Augustine and many others located the point of Christian life more or less exclusively in the vision of God after death (see 34‑A).³⁸ On this view, the realization of human goods is of little importance in itself; it becomes significant only in cases in which one’s eternal destiny is at stake.

St. Thomas attempts to integrate the natural and supernatural aspects of Christian life. A leading maxim in his thought is that grace perfects and completes nature and does not nullify it (see S.t., 1, q. 1, a. 8, ad 2; q. 2, a. 2, ad 1; q. 62, a. 5). Thus he firmly denies any opposition between the two, but he maintains their distinction and asserts their real relationship. Unfortunately, he is not able to clarify this relationship beyond a certain point; he leaves many unresolved difficulties as to how the fulfillment of human persons as such is related to their vocation to share in divine life.³⁹

The residual tension becomes particularly acute when one considers things by means of the nominalist theological perspective, which developed after the time of St. Thomas, for this perspective emphasizes certainty and sharply separates reason from faith. Certainty about human nature based on experience makes it clear that human life is deeply marked by sin; faith offers assurance of salvation, but this assurance seems incompatible with daily experience. For many minds in the late Middle Ages, the tension between nature and grace degenerated into irresolvable opposition.

The Renaissance and the Reformation were—or at least became—alternative ways of cutting through this opposition. The humanist option of the Renaissance, although initially not against Christian faith, developed into an ideal of humankind “uncontaminated” by grace, and ultimately into the secular humanism of the Enlightenment of the eighteenth century, which rejected the supernatural in favor of human nature and rejected faith in favor of autonomous human reason. The Christian option of the Reformation, although initially not opposed to humanism, developed into an ideal of New Testament Christianity “uncontaminated” by human elements, and ultimately into various forms of fideistic supernaturalism. These rejected corrupt human nature in favor of an altogether passively received grace; they also rejected the use of human reason in matters of ultimate significance in favor of the autonomous faith of the individual before God.

Secular humanism can reject altogether humankind’s calling to share in divine fellowship. Fideistic supernaturalism cannot reject altogether humankind’s natural condition and duties. The latter fact elicited an effort to isolate the secular from the sacred and to insulate the two domains from each other as completely as possible. The result was the increasing irrelevance of religion to the rest of human life. Catholic Christianity never accepted in principle the option of fideistic supernaturalism, but in practice even Catholics were deeply affected by this movement. Much popular teaching and preaching expressed hostility toward this world and its human goods and emphasized saving one’s soul.

Today the Catholic Church is confronted with substantial opportunities for ecumenism and evangelization. The reason is that events are making it clear that the forced option between human fulfillment and intimacy with God, between reason and faith—which led to the dichotomy between secular humanism and fideistic supernaturalism—is a highly unsatisfactory option, no matter which alternative is chosen.

On the one hand, few Christians today actually hold the negative views of human nature and the powers of reason and free choice which generated the doctrines Trent was compelled to condemn. Moreover, Christians today can see clearly the result of allowing the world to go its way without the illumination of faith; few are satisfied with a disincarnate Christianity which isolates faith in the individual relationship of the soul before God. Rationalistic philosophy no longer shapes Protestant theology, and most Protestant theologians who believe in divine revelation realize the difficulty of sustaining the claim that it is enshrined in the Bible, to be found there by individuals without a community whose faith somehow transcends and sustains the individual’s faith.

On the other hand, secular humanism is in deep trouble (see GS 18, 21). In all its varieties, individual and society are set against one another. The memory of Christian hope haunts post-Christian individuals and societies; they wish to be more than merely human. Contemporary humankind yearns for perfect liberty and perfect justice: the liberty of the children of God in the fellowship of the divine family—but without God. As a result, societies invent grandiose schemes to try to implement this hope; in so doing, they become totalitarian, attack fundamental values of the person such as life itself, and increasingly infringe upon individual liberty and privacy. Individuals experience the lack of a humane society, and so they suffer from identity crises—a sense of meaninglessness, boredom, alienation, and loneliness.

Post-Christian humankind cannot find its way back to the naiveté of paganism in which religion helped individuals and societies to live tolerable lives in this broken world, where finite persons must face not only their finitude but also their personal guilt and the inevitability of their own death. Having driven out Christian faith, secular humanism condemns nonbelieving persons either to face reality and live intolerable lives, or to evade reality by never adequate means, such as thin veils of individual escapism and rationalization or smothering blankets of social control and ideology. The option of post-Christian humankind for secular humanism has been a choice of death. Individuals and societies kill their unborn to solve their problems; to defend their ideologies, societies and individuals concur in their readiness to kill and be killed in an all-out war.

From this characterization of secular humanism, I conclude not simply that it ought to be rejected, but also that despite its seeming power and vitality, it is weak and dying. Eventually, the inhumanism of secular humanism will become obvious to everyone. At that point, a new phase of history, with new opportunities for evangelization, will begin.