Catholic probabilism
In Catholic moral theology, probabilism provides a way of answering the question about what to do when one does not know what to do. Probabilism proposes that one can follow an authoritative opinion regarding whether an act may be performed morally, even though the opposite opinion is more probable. It was first formulated in 1577 by Bartholomew Medina, OP, who taught at Salamanca.
Formulation
Probabilism is a way of approaching difficult matters of conscience. In such cases, according to probabilism, one may safely follow a doctrine approved by a recognized Doctor of the Church, even if the opposite opinion is supported by—or "more probable" as judged by—other criteria, such as those of science or other authoritative sources. Catholic probabilists believe that, whether there is question of the existence or of the cessation of a law, it is lawful to act on the less safe opinion if it is solidly probable, even though the safe view is certainly more probable.A more radical view, "minus probabilissimus", holds that an action is permissible if a single opinion allowing that action is available, even if the overwhelming weight of opinion proscribes it. This view was advanced by the Spanish theologian Bartolomé de Medina and defended by many Jesuits such as Luis Molina. It was heavily criticised by Blaise Pascal in his Provincial Letters as leading to moral laxity. Probabilism was already under heavy criticism by this time, which was amplified by the Letters. It has been said that they were "especially detrimental to probabilism's long-term reputation".
According to Probabilism, whenever a prohibiting law is certain, the subjects of the law are bound to abstain from performing the action which the law forbids, unless they are excused by one of the ordinary exempting causes. On the other hand, when it is certain that no law forbids an action, there is no obligation to abstain from performing it, under this doctrine. Between these two extremes there can be varying degrees of uncertainty about the existence or cessation of a prohibiting law. There is doubt in the strict sense when the intellect neither assents nor dissents, because either there are no positive arguments for and against the law, or the arguments for and against the law are equal in strength. The opinion which favours the law, and which is technically called the safe opinion, can be more probable than the opinion which favours liberty and which still retains solid probability.
In estimating the degree which is required and which suffices for solid probability, moralists lay down the general principle that an opinion is solidly probable which by reason of intrinsic or extrinsic arguments is able to gain the assent of many prudent men. Adherents to Probabilism hold that extrinsic authority can have sufficient weight to make an opinion solidly probable; but there is divergence of view in estimating what number of experts is able to give an opinion this solid probability. The prevailing theory holds that if five or six theologians, notable for prudence and learning, independently adhere to an opinion their view is highly probable, if it has not been set aside by authoritative decisions or by intrinsic arguments which they have failed to solve. Even one theologian that is regarded as highly authoritative, such as St. Alphonsus Liguori, is able to make an opinion probable in this sense. Under this view, no justification in terms of reason is sufficient to give an opinion solid probability, nor does the support of theologians who merely repeat the opinions of others.
If one opinion is not only less safe but also speculatively uncertain, then it is prohibited by Probabilism, until all reasonable effort has been made to remove the uncertainty, by considering the arguments on both sides and by consulting available authorities. One question at issue between different moral systems concerns the way in which the speculative uncertainty is changed into practical certainty; each system has what is called a reflex principle of its own, by which practical certainty can be obtained.
These various moral systems come into play only when the question concerns the lawfulness of an action. If the uncertainty concerns the validity of an action which must certainly be valid, it is not enough to act on mere probability unless, indeed, this is of such a nature as to make the Church certainly supply what is needed for the validity of the act. Thus, apart from necessity, these systems do not allow one to act on mere probability when the validity of the sacraments is in question. Additionally, they do not allow one to act on mere probability when there is question of gaining an end which is obligatory, since certain means must be employed to gain a certainly required end. Hence, when eternal salvation is at stake, these systems demand more than uncertain means as justification. Moreover, their conception of justice demands equality, and as such excludes the use of probability when the established rights of another are concerned. Consequently, if a certain debt has not been certainly paid, at least a payment pro rata dubii is required according to the prevailing view.
The central doctrine of probabilism is that in every doubt that concerns merely the lawfulness or unlawfulness of an action it is permissible to follow a solidly probable opinion in favour of liberty, even though the opposing view is more probable. Probabilists apply their theory only when there is question merely of the lawfulness or unlawfulness of an action, because in other cases certainty might be demanded on various grounds, as happens when the validity of the sacraments, the attainment of an obligatory end, and the established rights of another are concerned. They apply their doctrine whether the doubt about the lawfulness or unlawfulness of an action be a doubt of law, or a doubt of fact which can be reduced to a doubt of law. Thus if it is solidly probable that Friday morning has not yet set in, there is a doubt of fact which can be reduced to a doubt of law as to whether it is lawful in the circumstances to take meat. They also apply their doctrine not merely to human but also to Divine and natural laws, on the ground that the Divine legislator is not more exacting than a human legislator. They apply their principles whether the existence or the cessation of a law is concerned, since, in their estimation, liberty is always in possession. They also apply their doctrine even though the person whose action is in question believes that the safe opinion is the more probable opinion. If, however, he looks on the safe opinion as morally certain, he cannot lawfully use the opinion of others who differ from him. Nor can a person on the same occasion use opposing probabilities in his favour in reference to several obligations of which one or another would be certainly violated; thus a priest cannot lawfully take meat on the probability that Friday has already elapsed, and at the same time postpone the reading of Compline on the probability that Friday will not elapse for some time. Finally, probabilists insist that the opinion in favour of liberty must be based on solid arguments and not on mere flimsy reasons which are insufficient to gain the assent of prudent men.
History of probabilism
After its formulation by the Dominican Medina in Salamanca late in the 16th century, probabilism was widely held by respected Catholic theologians, including many Jesuits and Dominicans, for the next century. Jesuits such as Gabriel Vásquez further developed probabilism, distinguishing intrinsic, argument-based probabilism and extrinsic, authority-based probabilism. Abuses of probabilism led to moral laxism such as that of Juan Caramuel y Lobkowitz.Precursors
Fathers, doctors and theologians of the Church at times solved cases on principles which apparently were probabilist in tendency. Augustine of Hippo declared that marriage with infidels was not to be regarded as unlawful since it was not clearly condemned in the New Testament: "Quoniam revera in Novo Testamento nihil inde praeceptum est, et ideo aut licere creditum est, aut velut dubium derelictum". Gregory of Nazianzus laid down, against a Novatianist writer, that a second marriage was not unlawful, since the prohibition was doubtful. Thomas Aquinas maintained that a precept does not bind except through the medium of knowledge; and probabilists are accustomed to point out that knowledge implies certainty.However, many theologians were Probabiliorist in their principles before the sixteenth century, including Sylvester Prierias, Conradus, and Thomas Cajetan. Consequently, Probabiliorism had already gained a strong hold on theologians when Medina arrived on the scene.
Bartholomew Medina
, a Dominican, was the first to expound the moral system which is known as probabilism. In his Expositio in 1am 2ae S. Thomae he wrote:His system soon became the common teaching of the theologians, so that in the introduction to his Regula Morum Father Terill maintained that until 1638 Catholic theologians of all schools were probabilists. There were exceptions such as Rebellus, Comitolus and Philalethis, but the great body of the theologians around 1600 were on the side of Medina.
Jansenist opposition
With the rise of Jansenism a new phase in the history of the probabilist controversies began. In 1653 Innocent X condemned the five propositions taken from Jansen's book Augustinus, and in 1655 the Louvain theologians condemned probabilism. Tutiorism was adopted by the Jansenists, and the Irish Jansenist theologian John Sinnichius, was the foremost defender of the Rigorist doctrines. He held that it is not lawful to follow even a most probable opinion in favour of liberty. Jansenist Rigorism spread into France, and Pascal attacked probabilism in his Lettres Provinciales, which were in turn condemned by Alexander VII in 1657.After the condemnation of Jansenism, several 18th century theologians unfolded a moderate form of Tutiorism. Others favoured Laxism, which maintained that a slightly probable opinion in favour of liberty could safely be followed.