PROBABILISM
441
PROBABILISM
husband, but once converted she persuaded him to
follow her example. She had celebrated in an epic
poem now lost the wars between Const ant ine and
Magnentius. After her conversion she wrote a zcnio
in hexameter verses in which she relates sacred historj'
in terms borrowed exclusively from \'irgil. The story
of the Old Testament is briefly outlined, the author
dwelling only on the Creation, the Fall, and the
Deluge. The larger portion of the work recounts the
life of Christ according to the Gospels. But the ac-
tion of the poem is constrained and unequal, the man-
ner absurd, the diction frequently either obscure or
improper; nevertheless the work had a certain pop-
ularity during the Middle Ages.
Glover, Life and Letters in the Fourth Century (Cambridge, 1901), 144: for the latest edition, with an exhaustive study, see ScHENKL in Poet. Christ, min, I, Corp. script, ecdes. tat. (Vienna,
1888). Paul Lejay.
Probabilism is the moral system which holds that, when there is question solely of the lawfulness or un- lawfulness of an action, it is permissible to follow a solidly probable opinion in favour of liberty even though the opposing view is more probable.
I. State of the Question. — When a prohibiting law is certain, the subjects of the law are bound to abstain from performing the action which the law for- bids, 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. Be- tween these two extremes there can be varying degrees of uncertainty about the existence or ces-sation of a prohibiting la%v. 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. Again, the opinion which favours the law can be most probable, and the opinion wiiich favours liberty only slightly probable. In the same way the opinion which favours liberty and which is technically called the less safe opinion, can bo more probable than the opposing view, or can be most probable.
In estimating the degree which is required and which suffices for solid probability, moralists lay down the general principle that an opinion is solidly prob- able which by reason of intrinsic or extrinsic argu- ments is able to gain the a-ssent of manj- prudent men. All admit that extrinsic authority can have sufficient weight to make an opinion solidly probable; but there is divergence of \-iew in estimating what number of experts is able to give an opinion this solid probabil- ity. The prevailing theory amongst Probabilists holds that if five or six theologians, notable for prudence and learning, independently adhere to an opinion their view is solidly probable, if it has not been set aside by authoritative decisions or by intrinsic arguments which they have failed to solve. Even one theologian of very exceptional authority, such as St. Alphonsus Liguori, is able to make an opinion solidly probable, as we know from the official declarations of the Holy See. All moralists agree that mere flimsy reasons are insufficient to give an opinion solid probability, and also that the support of many theologians who are mere collectors of the opinions of others is unable to give sohd probability to the view which they maintain.
Non-Catholics who bring charges of laxity against the moral sy.stems which Catholic theologians uphold, often forget that the Catholic Church, in theory and in practice, has condemned various views in favour of liberty which are based on insufficient data.
If the less safe opinion is speculatively uncertain, it is unlawful to follow it in practice, until all reasonable effort ha.s been made to remove the uncertainty, by
considering the arguments on both sides and by con-
sulting available authorities. It is unlawful, also, to
act on the less safe view unless the speculative uncer-
tainty has been changed into practical certainty that
the action to be performed is lawful. The whole
question at issue between different moral systems con-
cerns 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 that the action to
be performed is lawful. Rigorism, or, as it is fre-
quently called, Tutiorism, held that the less safe
opinion should be most probable, if not absolutely cer-
tain, before it could be lawfully put into practice,
while Laxism maintained that if the less safe opinion
were slightly probable it could be followed with a safe
conscience.
These two v-iews, however, never received serious support from Cathofic theologians, and were formally condemned by the Holy See. At one time or another in the historj- of the Church three other opinions gained many adherents, v^ome theologians, who put forward the system kno%\Ti as Probabiliorism, hold that the less safe opinion can be lawfully followed only when it is more probable than thesafe opinion. Others, upholding ^Equiprobabilisni, maintain that, when the uncertainty concerns the existence of a law, it is law- ful to follow the less safe opinion when it has equal or almost equal probability with the safe opinion, but that, when there is question of the cessation of a law, the less safe opinion cannot lawfully- be followed un- less it is more probable than the safe \'iew. Others again, who adhere to Probabilism, 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. In recent years a system known as Compensationism has tried to reconcile these three opinions by holding that not only the degree of probability attaching to various opinions must be taken into account, but also the importance of the law and the degree of utility attaching to the performance of the action whose morality is in ques- tion. The more important the law, and the smaller the degree of probability attaching to the less safe opinion, the greater must be the compensating utility which will permit the performance of the action of which the lawfulness is uncertain.
From what has so far been said it is clear that these various moral systems come into plaj' 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 lawful 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 neces- sity, it is not lawful to act on mere probability when the validity of the sacraments is in question. Again, it is not lawful to act on mere probability when there is question of gaining an end which is obligatory, since certain means must be emploj'cd to gain a certainly retjuired end. Hence, when eternal salvation is at stake, it is not lawful to be content with uncertain means. Moreover, the virtue 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 paj-ment pro rata dubii is required ac- cording to the prevailing view. It is evident, then, that the question which arises in connexion with the moral systems has to do solely with the lawfulness or unlawfulness of an action.
II. History of Probabilisii. — Probabihsm as a moral system had no history prior to the end of the sixteenth century. Fathers, doctors and theologians of the Church at times solved cases on principles which apparently were probabilist in tendency. St. .Vugus-
