Moral Theology. Charles J. Callan
against obligation create invincible ignorance, since it excludes the less probable opinion for obligation, and makes one assent unwaveringly and in good faith, even though erroneously, to the judgment that one is not bound.
(b) It is no more difficult to decide what is more probable than to decide what is equally probable, or truly and solidly probable; nor is the same skill and attention expected in all persons and cases, but each person must judge according to the best light he has, and each case must receive the measure of attention its importance calls for. If Probabiliorists may become scrupulous, may not Probabilists become lax?
687. The debate between Probabiliorism and its adversaries is not often heard today, as most modern moralists give their allegiance either to Equiprobabilism (a modified Probabiliorism) or to Probabilism.
688. Equiprobabilism.—The doctrine of Equiprobabilism is a middle way between Probabiliorism and Probabilism. Thus: (a) it agrees with Probabiliorism in holding that it is not lawful to follow the less safe, if the safer is more probable, or if the safer is equally probable, and the question is about the cessation of the law; (b) it agrees with Probabilism in holding that it is lawful to follow the less safe, if the safer is only equally probable, and the question is about the existence of the law.
689. The principle that "it is not lawful to follow the less safe, if the safer is equally probable and the question is about the cessation of the law," is defended as follows by Equiprobabilists:
(a) In real doubt we should decide in favor of that side which is possession. But, when doubt is about the cessation of a law, the law is in possession; for there is no question that it was made. Therefore, in such a doubt we should decide for the safer side, that is, that the law has not ceased.
(b) A certain obligation is not complied with by a doubtful fulfillment. But doubts about the cessation of the obligation of law usually arise from a probability that one has already fulfilled the law. Therefore in such cases we should decide that the law has not been fulfilled—that is, that its obligation has not ceased.
690. The Probabilists reply that: (a) it is not true that, in equiprobability about the cessation of law, the law is in possession; for liberty is naturally prior to law, and hence has possession in doubt; (b) nor is it true that an obligation that has probably been complied with or removed is certain.
691. The Equiprobabilists answer: (a) liberty was in possession, until it was dispossessed by the making of the law; (b) an obligation that certainly existed must be held as certainly in existence, until the contrary is proved; whereas a fact, such as dispensation, abrogation, or fulfillment, is not proved if it is only probable.
692. The principle that "it is lawful to follow the less safe side, if the safer is only equally probable and the question is about the existence of the law," is defended as follows by Equiprobabilists:
(a) In real doubt we should favor the side that is in possession. But when doubt is about the existence of a law, liberty is in possession; for liberty is prior to law. Therefore, in such doubt we may decide that there is no obligation.
(b) An uncertain law does not oblige, if one is invincibly ignorant of its existence. But, when there are equiprobable reasons against the existence of a law, one is invincibly ignorant of its existence. Therefore, in such cases one is not obliged.
693. The principle that "it is not lawful to follow the less safe side if the safer side is more probable," is defended as follows by Equiprobabilists:
(a) In doubt improperly so called—that is, in that condition of mind in which there is no fluctuation between equal arguments, but only some indecision between the more and the less probable—we should decide in favor of the more probable, as being morally certain. Hence, it is not lawful to follow what is less safe and less probable.
(b) A law sufficiently promulgated obliges. But, when it is more probable that a law was made or is in force, such law is sufficiently promulgated to the conscience. Hence, the safer side must be followed, if it is more probable.
694. Probabilist Criticism of the Foregoing Arguments.
(a) If the excess of the more probable over the less probable is so great that the latter is only slightly or doubtfully probable, the more probable is equivalent to certitude; for certitude is assent without fear of the opposite, and the fear of the opposite in such a case would be so slight that it may be considered as non-existent. If the excess is not so great, the less probable remains solidly and certainly probable, and the more probable is not certitude, but opinion (that is, assent with fear of the opposite). The Equiprobabilists are speaking of greater probability in the second sense, and hence they are wrong when they identify it with certitude (see above, 654).
(b) A law must be so promulgated to the conscience that one knows the law or could know it with sufficient diligence; it does not suffice that one can get no further than opinion. It would be unreasonable to oblige one to observe not only what is the law, but also what seems to be the law. Now, he who has only more probable opinion that he is bound by some law, does not know that such obligation exists; he only knows that it seems to exist.
695. Reply of the Equiprobabilists.-(a) The more probable always removes the appearance of truth from the less probable. Hence, he who recognizes an opinion as more probable can assent to it without any fear of error.
(b) One who holds it as more probable that he is obliged by a certain law, does not know for certain that he is obliged by reason of that law; but he does know for certain that he is obliged by reason of a higher law. Superior to every particular law is the general law that nothing may be done that will deprive law of its efficacy. But law loses its efficacy if each one is free to decide that he is not bound even when the greater weight of probability is to the contrary.
696. General Arguments in Favor of Equiprobabilism.—(a) From Authority.—St. Alphonsus Liguori, who holds a unique place in the Church as a moralist, preferred Equiprobabilism to every other moral system; and his views are followed not only by his own Congregation, the Redemptorists, but by many others.
(b) From Comparison with Other Systems.—Truth lies midway between extremes; for truth is lost either by exaggeration or by defect. But Equiprobabilism is a happy medium between Probabiliorism inclining to Rigorism, and Probabilism inclining towards Laxism. Hence, the relation of Equiprobabilism to other systems is in its favor.
(c) From the Character of Its Teaching.—According to principles of justice universally admitted as true, a judge should pronounce sentence in favor of the more probable when there is evidence of unequal weight and in favor of that which is in possession when there is evidence of equal weight. But these principles ought to be of universal application. Therefore, Equiprobabilism does right in making these the guiding principles for the court of conscience.
697. Probabilist Criticism of these Arguments.—(a) St. Alphonsus is one of the greatest moral theologians of the Church. Whether in his later years (1762–1787) he taught Equiprobabilism, is a matter of dispute among those who are familiar with his writings. But there is no doubt that in his mature age (1749–1762), when he wrote his Moral Theology, he was a Probabilist.
(b) Probabilism can likewise claim that it stands midway between the extremes of Rigorism (represented by Probabiliorism and Equiprobabilism), on the one side, and of Laxism, on the other side.
(c) The principle of possession invoked by Equiprobabilism applies to matters of justice, because there is a presumption that he who holds property has a right to it, and also because human laws must favor him who is in possession, lest property rights be left uncertain and disputes be multiplied. The principle of possession does not apply, however, to other matters; if the law obliged one yesterday, how can that create a presumption that it obliges one today, if one has good reasons for thinking the obligation has ceased? And as for human ordinances, while they have jurisdiction over external goods and may award them in case of doubt to the possessor, they have not, and have never claimed, the right to make the principle of possession a rule for solving all difficulties about duty.
The principle of Probabiliorism for which the Equiprobabilists claim the authority of judicial practice certainly does not apply to criminal cases, for in these preponderance of evidence