Probabilism is one of several so-called moral systems; these are methods of resolving doubts of conscience.⁹ A person is not sure what is right; to act with one’s conscience in this state certainly is a sin, for to do so is to be ready and willing to do what is wrong. One must find some way of reaching a confident judgment that what one proposes to do is legitimate.

Probabilism is proposed as a way of reaching this confidence. However, it is a way which only makes sense within a certain context, namely, the context in which the Church’s moral belief and teaching are regarded as a body of law, and this body of law becomes morally obligatory by way of one’s responsible acceptance in faith of the Church as a moral authority. While faithful Catholics have never confused the Church’s moral teaching with mere social convention, in modern times theological reflection proceeded in a way more consistent with legalism than with a clear appreciation of the status as truths of received Christian moral norms.

In the Church after Trent there was a great tightening of discipline in general and of the practice of the sacrament of penance in particular. At the same time, because of the cultural transformation worked by the dawn of modern economics and social structures, new and often difficult moral questions rapidly proliferated. Rationalism, an outgrowth of medieval nominalism, took hold in philosophy and theology, and legalism took hold in moral theology.

How the level of social convention is a necessary one in the development of conscience was explained previously (3‑A). Every normal child goes through this stage, especially during the period between about seven and fourteen; probably few decent persons ever wholly emerge from it. The mentality of conscience at this level is highly legalistic. Virtually the only real sin is disobedience. Moral norms are felt as limits on one’s behavior imposed by parents, teachers, society at large, the Church, and ultimately God, who authorizes and backs up all the other authorities.

Where no moral norm is in force, one is free to do as one pleases, and no moral issue arises. If one is not sure whether something is morally acceptable or not, one simply asks someone in authority: “Is it all right if I . . .?” If the answer is affirmative, one proceeds with confidence; one is okay; the superego, still operative and more or less integrated, allows one to proceed without anxiety. Thus, this legalistic system of childhood limits one’s moral responsibility. There is no moral responsibility about most matters—namely, about all those questions which authorities do not seem to care about one way or another. Where there is moral responsibility, one can fulfill it by obtaining a suitable approval: “Mommy said it was all right for me to . . ..”

Classical modern moral theology organized the whole of the Church’s moral belief and teaching into a body of law. The truth of Christian moral norms always was affirmed. Nevertheless, the intrinsic relationship between right action and basic human goods, and the inherent reasonableness of acting morally tended more and more to be ignored. Moral theology extended only to moral issues, and these were thought to concern only some aspects of one’s life. In effect, morality was limited to matters concerning which strict and more or less general precepts can be laid down. Most of these necessarily are negative, because it is much easier to determine what is morally wrong than what is morally right. Where the moral law was silent, the faithful were free—free to do as they pleased, but also free to be caught up in the Christian life and to grow in holiness according to the guidance of systems of asceticism and spirituality, which were quite separate from the legalistic moral theology.

In this context, the faithful looked to confessors for advice concerning doubts of conscience. Confessors looked to their bishops and/or teachers of moral theology. The latter looked to the “doctors”—the more eminent moral theologians who published works which gained recognition and respect in the Church. Eventually a certain number of more systematic works in moral became widely used and accepted for seminary training; these works were the “approved authors.” The doctors and, later, the approved authors not only systematized and summarized received Christian moral teaching, which had been handed down from the Middle Ages; they also developed the Church’s moral teaching. They refined it in regard to innumerable questions which had been treated before and expanded it to settle innumerable questions—especially in the area of justice—which never had been treated, because they had not arisen prior to the development of modern business, politics, and law.

The teaching authority of the Church functioned, largely through the activity of the Holy See, as a supreme court overseeing this legal system. The various commended doctors and approved authors came to have the function of lower courts; they could settle cases within the boundaries of the body of moral law and the authority conceded to them by the magisterium. Moral theology and canon law came close together; sometimes they merged into one.

There were various difficulties in this situation. One was that the approved authors and commended doctors did not always agree with one another. Every child is familiar with this difficulty. What must one do when mother says one thing and teacher says the opposite? A method for resolving this type of question is essential. Hence the problem of moral systems, which emerged in the Church in the sixteenth century. Some thought one always is obliged to accept the strictest view in favor of law and against doing as one pleases. This position is tutiorism; it is rigoristic, and the Church rejected it. Others thought one might always adopt the view most favorable to liberty. This position is laxism; it is like allowing a child to go from authority to authority until it finds one who absentmindedly gives approval. The Church also condemned this position.

In this way the problem which probabilism and probabiliorism answer was framed.¹⁰ These are not methods of forming one’s conscience independently of the Church’s teaching authority. Far from it. One who knew for sure what is right and wrong did not have a doubtful conscience; one who had a doubtful conscience was expected to find an authoritative solution to obey. The only sources of authoritative solutions were moral theologians approved by the magisterium and working within the unquestioned body of her already-definite moral tradition. The problem is: When these sources of authoritative solutions to doubts of conscience disagree among themselves, how can one settle the doubt?

The theses of probabilism and probabiliorism are ones freely held and disputed in Catholic theology. Neither Scripture, nor tradition, nor the documents of the magisterium either approve or reject them.¹¹ They are only tacitly approved by the magisterium, in that many approved authors defend one of them, probably including St. Alphonsus Ligouri, who is a doctor of the Church especially commended in moral theology.¹²