(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 against an accused 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 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.?