Moral Theology. Charles J. Callan
is not to be followed if there is a reasonable doubt. In civil cases judges apply the principle of probabiliorism, but it does not follow that conscience should do the same, for the circumstances are different. The judge is seeking to decide which of two litigants has the more likely claim, and hence he is bound to declare for the side that has stronger evidence. Conscience is seeking to decide whether an obligation is certain or uncertain, and hence it is not obliged to decide for obligation when this is more probable, but still not certain.
698. Answer of Equiprobabilists to this Criticism.—(a) Granted that St. Alphonsus once held Probabilism, he rejected it later emphatically, and when dying declared that his former defense of Probabilism was the only thing that gave him anxiety.
(b) Equiprobabilism is further removed from Rigorism than Probabilism is from Laxism. It hears both sides of the question—that for liberty and that for law—before it decides. Probabilism is satisfied to hear one side, that for liberty; or at least it does not compare the two sides.
(c) The principle of possession is applied more strictly in cases of justice; for, since justice implies a more exact equality and a more rigorous right than other virtues (see 154), disputes in matters of justice demand stronger proofs. But every virtue renders to someone his due, and hence there is no reason why principles applicable to justice should not be applicable to other virtues also. The principle of Probabiliorism, likewise, is just as applicable to the court of conscience as to the civil court, since in both courts the aim is to get the truth as nearly as possible.
699. General Arguments Against Equiprobabilism.—(a) Theoretical Objection.—If we judge Equiprobabilism by its arguments, we find it unconvincing, for that which is old in it does not agree with that which is new, and that which is new argues equally well for Probabilism. Thus, the old arguments for Probabiliorism mean in the last analysis that the greater probability deprives the opposite side of all solid probability; logically, then, one should conclude that equal probability deprives both sides of all solid probability, since one neutralizes the other. The new arguments are drawn from the principles that in doubt one should decide in favor of the side in possession, that a doubtful law does not oblige, etc.—all of which principles, as we shall see, favor Probabilism.
(b) Practical Objection.—If we judge Equiprobabilism by its adaptibility for use, we find it wanting. A moral system should be one that can be easily understood and applied, otherwise it is unworkable and useless. But Equiprobabilism is so complicated and abstruse that even the professional theologians who hold it are often at a loss how to apply it, and are found to give inconsistent decisions. How can it be expected, then, that anyone else will be able to decide whether the law or liberty is is possession, whether the degree of probability on one side is greater than or equal to that on the other, whether the question has to do with the existence of the law or its cessation, etc.?
700. Replies of the Equiprobabilists.—(a) The old (i.e., probabilioristic) principles of Equiprobabilism are not contrary to the new. A more probable opinion not only balances the opposition by its equal arguments, and thus puts away doubt, but it also wins assent by the surplus in its favor, and thus certitude is had. When the two opposites are equally probable, there is a state of true doubt, but certitude is had by recourse to the principles of possession and doubtful law. These principles proper to Equiprobabilism do not favor Probabilism, if one is impartial in one's use of them, and willing to use them against as well as for liberty.
(b) Equiprobabilism is not more difficult in its application than Probabilism. It does not require that one determine minutely and exactly the greater or equal probability of the arguments for law and for liberty, or that one devote extraordinary diligence to the solution of the problem. All it requires is that one consider the matter seriously, weigh the arguments on both sides impartially, and decide to the best of one's ability which side appears to be more probable or to have the presumption in its favor.
701. Probabilism.—The meaning of Probabilism can be seen from a comparison with the opposite systems. (a) Unlike Probabiliorism and Equiprobabilism, Probabilism does not require a greater or equal probability, but permits one to follow what is less probable; (b) unlike Laxism, it does not allow one to follow what is only slightly or uncertainly probable, or to apply the system to all cases of doubt.
702. A judgment is probable when it is supported by arguments that make it seem true, although there may remain reasons for doubt. Examples are conclusions based on analogy, on hypothesis, on the opinions of others, or on the calculus of probabilities.
703. Probability is of various kinds. (a) It is absolute or relative, according as the supporting reasons are grave, either when considered alone, or when compared with the objections. Even the Probabiliorists admit that an opinion that is merely probable may be followed, if it is solidly probable and there is no argument against it (see 649). (b) We have solid or slight probability, according as the supporting motives are or are not such as would move, if not convince, a prudent man—that is, a man who shows good judgment in most things. (c) We have certain or uncertain probability, according as a person is sure or not, after reasonable consideration, that the arguments seem valid and the opinion likely. (d) Probability is internal or external, according as the arguments are drawn from the matter at issue itself (i.e., from its nature, properties, causes, effects, etc.) or from the authority of the doctors who have defended an opinion.
704. Relative probability according to logicians remains even when a lesser is compared with a greater probability. (a) If the opposing arguments are drawn from different sources, the more probable does not attack the less probable, and hence does not weaken its probability. Example: An intrinsic argument has more weight than a mere appeal to authority, but it does not attack the opposite argument, and hence does not diminish its probability. (b) If the opposing arguments are drawn from the same source, each one weakens the opposite, since there is direct opposition. But the more probable does not destroy the less probable, since, in spite of the greater appearance of truth on the one side, there still remains room for the possibility that the other side may be true.
705. A moral judgment is solidly probable when the following conditions are present:
(a) For the judgment there must be an intrinsic or extrinsic argument that would be considered weighty by a prudent man. Example: An opinion that has the support of a universally acknowledged authority is strongly probable, whereas, if it has only the support of one obscure writer, it is only slightly probable.
(b) Against the judgment there must be no decisive argument from authority or reason. Example; The judgment that a certain course of action is lawful because St. Alphonsus permits it, is ordinarily solidly probable; it is not probable, however, if the opinion of St. Alphonsus (e.g., that Catholics may act as sponsors in non-Catholic baptisms) has been disallowed by the Church, or if the argument he uses (e.g., that concerning the amount that constitutes grave matter in theft, which reasons from conditions in his day) is not strong.
(c) The arguments for the judgment must retain their probability, if they are set over against the arguments for the opposite. Manifestly, if the arguments are all satisfactorily answered by the opposite side, the judgment based on them ceases to retain the appearance of truth. Probabilism does not require, however, that one determine the relative degrees of probability in opposite opinions.
706. It is not sufficient according to the Probabilists that another be certain of the probability of an opinion; but the person who follows the opinion must himself be certain that it is solidly probable.
707. Regarding the kind of authority necessary to make an opinion solidly probable from external evidence, Probabilism teaches:
(a) that absolute probability (that is, such a weight of authority as would appear strong even to the most learned) ought to be estimated by quality rather than quantity—by the learning, prudence, impartiality, and independent study of the authors, rather than by their numbers. If five distinguished moralists arrive by separate study at the same conclusion (i.e., that an opinion is probable), or if one of special reputation in a matter under question supports the probability of an opinion, the argument from authority is strong;
(b) that relative probability (that is, such a weight of authority as suffices for one who is unlearned, such as a child, a halfwit, an uneducated