Equiprobabilism

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.?

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.