Article First. On the Various Systems.

226. For what it serves. The moral system must perform its office whenever there is a doubt concerning the obligation of a law which cannot be solved directly. Namely, when a founded doubt concerning the liceity of his action or omission and concerning the existence of a law, whether prescribing or prohibiting, arises for the agent, first of all he is bound seriously to inquire into its existence. But if he has arrived at certain knowledge of the law, he must observe it holily (n. 143). Yet innumerable are the circumstances of human life in which doubt concerning the obligation of a law and therefore concerning the liceity of an action arises, without its certain knowledge being able to be reached. Here the question offers itself: in what way, in circumstances of this kind, ought man to conduct himself according to the will of God? Namely, it is asked whether, from the will of God, the supreme legislator, even doubtful laws, concerning whose obligation it is not established with certitude, must be observed, or whether from the will of the same it suffices that laws be observed of whose existence we have certain knowledge. And if it is established that from the will of God it is not necessary that even doubtful laws be observed, it is further asked by what reason, while doubt concerning the obligation of the law remains, one can arrive at a practically certain conscience. For from doubt concerning the obligation of a law there immediately arises a practically doubtful conscience; but it is not lawful to act with a practically doubtful conscience. Therefore any moral system proposes to itself a twofold question to be solved: concerning the obligation of a doubtful law and concerning the way and method of arriving at a practically certain conscience when there exists doubt concerning the liceity of an action in general.

¹ Cf. Fr. Mannhart, De ingenua indole probabilismi (Augustae Vindel. 1759). Leimbach, Untersuchungen uber die verschiedenen Moralsysteme (Fulda. Aktiendruckerei. 1894). Ludwigs, Zur Frage uber das Moralsystem (Zeitschrift f. k. Theol. 1878 S. 1 ff.). Der Katholik, 1874, Probabilismus und probabilistische Systeme. Kirchenlexikon, Moralsysteme. Schindler S. 213 ff.

227. What it is. By the name of moral system is understood a complex of principles by the help of which, from speculative doubt concerning the obligation of a law, one can arrive at a practically certain conscience.

It is called a moral system: a. because it contains several principles cohering among themselves by a logical connection, by whose help the chief question of moral theology is solved; b. because it exercises a very great influence on the whole of moral theology and its character, since the principle of the system is a most fertile principle of moral theology, which supplies a norm of judging concerning the existence of a precept and therefore a norm of acting in very many questions.

228. How many there are. Moral systems are numbered as altogether six, which solve the proposed questions in a diverse way: absolute tutiorism, mitigated tutiorism, probabiliorism, equiprobabilism, probabilism, and laxism. In order that the formula by which each system is exhibited may be understood, this must be noted: whenever the existence or obligation of a law is doubtful, two opinions more or less probable are opposed to one another, of which one stands for the obligation of the law, the other for liberty from the law. The formulas of the individual systems are called their principles, which are customarily exhibited in this way:

1. Absolute tutiorism teaches: we must follow the safer opinion (for the law), even if the contrary opinion for liberty is most probable.

2. Mitigated tutiorism teaches: we must follow the safer opinion, unless the contrary opinion for liberty is most probable.

3. Probabiliorism teaches: we can follow the less safe opinion for liberty if it is more probable than the contrary opinion for the law.

4. Equiprobabilism teaches: we can follow the less safe opinion for liberty if it is equally probable as the opposite opinion for the law.

5. Probabilism teaches: we can follow the less safe opinion for liberty if it is truly probable, even if the opposite opinion for the law is more probable.

6. Laxism teaches: we can follow the less safe opinion for liberty even if it is only tenuously or doubtfully probable.

If we compare the principles of these systems with one another, these things are manifest:

a. All the systems can be referred to two classes, of which one contains tutioristic or antiprobabilistic systems, namely the two former, and the other probabilistic systems, namely the four latter. The former favor law more, the latter liberty more; the former are systems of the Jansenists, the latter systems of Catholics.

b. These two kinds of systems differ from one another especially in this, that tutioristic systems admit only a directly certain conscience and therefore reject the use of probable opinion and of reflex principles; but probabilistic systems admit an indirectly certain conscience and therefore also declare licit the use of probable opinion and reflex principles for forming an indirectly certain conscience.

c. Two of these systems, absolute tutiorism and laxism, are illicit, as being reprobated by the Church; but the other four are indeed licit, since they are not reprobated by the Church, yet only one can be true, because they mutually exclude one another.