§ I. On Preliminary Notions

The notions which recur most, and the prior exposition of which is of the greatest importance, are those of certainty, opinion, and doubt. For the sake of completeness we shall add some points concerning the notion of probability, the immoderate use of which has so greatly entangled the treatise on conscience.

I. Certainty is the state of a mind adhering to some knowable thing without a prudent fear of erring. It is said "without a prudent fear"; for an imprudent fear is not always absent even from the certainty of faith. "But sometimes," says Aquinas, "the possible intellect is determined to this, that it totally adhere to one part" (De Verit., q. 14, a. 1). And elsewhere: "Certainty is nothing other than the determination of the intellect to one" (In III Sent., dist. 23, q. 2, a. 4, sol. 3).

Certainty is distinguished into metaphysical, physical, and moral, according as it is founded in the essences of things, in physical laws, or in moral laws, that is, those which govern the inclinations and morals of human beings.

Moral certainty is usually divided into strict and broad. Strict certainty is that of which we have just spoken. Broad certainty is that which includes some prudent fear, or "which does not exclude every prudent fear" (St. Alphonsus, I, 81); hence it cannot be called certainty properly so called, but must be referred to opinion, as will be more evident from what is to be said.

II. Opinion is the state of a mind adhering to some knowable thing with a prudent fear of erring. "But sometimes the intellect is inclined more to one thing than to another; yet that which inclines it does not sufficiently move the intellect to this, that it determine it totally to one of the parts; hence it indeed accepts one part, yet it always doubts about the opposite: and this is the disposition of one opining, who accepts one part of a contradiction with fear of the other" (St. Thomas, De Verit., q. 14, a. 1). And elsewhere: "One opining has thought without perfect assent; but he has something of assent, insofar as he adheres to one more than to another" (In III Sent., dist. 23, q. 2, a. 2, sol. 1). Moreover, one opining gives the fearful assent of which there has been speech to a proposition, or to one part of a contradiction, as true. "One opining," says St. Thomas, "says (certainly with fear) that what he opines is true" (In VI Eth., lect. 8).

Corollary I. One who opines that a law exists does not wholly ignore the existence of the law, but knows it in some measure, or truly has a positive cognition of it, although a weak one.

Corollary II. One who opines that a law exists holds the opinion favoring the law as certainly more probable, but the opinion which supports liberty as certainly less probable. But since a small excess of probability is commonly not clearly, and therefore not certainly, perceived, an opinion that is certainly more probable will commonly be notably more probable, or certain in a broad sense, imperfectly and improperly (cf. St. Alphonsus, Lettere, III, n. 219).

III. Doubt is the state of a mind fluctuating between two parts of a contradiction because of no motives, or because of equal motives on both sides. "Our intellect," says the Angelic Doctor, "stands in different ways with respect to the parts of a contradiction. For sometimes it is not inclined more to one than to the other, either because of a defect of things moving it, as in those problems concerning which we do not have reasons, or because of the apparent equality of those things which move toward each part: and this is the disposition of one doubting, who fluctuates between two parts of a contradiction" (De Verit., q. 14, a. 1). Again: "When a man does not have a reason for one part more than for the other, either because he has one for neither, which belongs to one who does not know, or because he has one for each, but an equal one, which belongs to one doubting, then he in no way assents, since his judgment is in no way determined, but is equally disposed toward different things" (III Sent., dist. 23, q. 2, a. 2, sol. 1). Nor does St. Alphonsus speak otherwise: "A doubtful conscience is that which suspends assent for each part of the doubt, and remains uncertain and hesitating" (I, 20). "A doubtful conscience is that which, remaining undeliberated, suspends assent for each part" (Homo Apostolicus, tr. I, n. 12). Therefore the Doctors whom we have cited teach that one doubting gives assent, not even a weak assent, to neither part of a contradiction as true. St. Alphonsus gives the ultimate reason for this matter in these words: "For although, when reasons of equal weight support each opinion, each would have force to move the intellect to assent if they were not mutually opposed; nevertheless, since here they are directly opposed to each other, each is now deprived of the force of drawing assent to itself, and by reason of the equality of the weights one destroys the other, and both therefore bring forth nothing except mere doubt" (Dichiarazione del Sistema, appendix, n. 21).

Suspicion is reduced to doubt, that is, the state of mind in which either opinion seems to someone doubtfully more probable. "As all," says St. Alphonsus, "both Probabilists and Antiprobabilists, agree, when there is a slight preponderance between two opinions, so that the excess is very slight and doubtful, then both opinions are regarded as equally probable according to that common axiom: A little is reckoned as nothing" (I, 55, 7th ed.). Likewise St. Thomas: "Certain acts of the intellect have unformed thought without firm assent, whether they incline to neither part, as happens to one doubting, or incline more to one part, but are supported by some slight sign, as happens to one suspecting, or adhere to one part, yet with fear of the other, which happens to one opining" (II-II, q. 2, a. 1). Again: "Reason takes what is little as though it were nothing" (I-II, q. 14, a. 4).

Doubt, or a doubt, is distinguished:

1. Into strict and broad doubt. Strict doubt, or doubt properly so called, is that which we have just described. Broad doubt is some such doubting or hesitation which remains in the state of opinion; hence it is only doubt taken improperly.

Strict doubt is divided into positive and negative, according as someone doubts because of equal or nearly equal motives, or because of no motives, or slight motives, on either side.¹

2. Into speculative and practical doubt, according as the doubt concerns the morality of an action considered in the abstract, for example whether it is licit to paint on a feast day, or concerns the morality of an action viewed in particular, for example whether it is licit for me to paint on this feast day (St. Alphonsus, I, 21).

3. Into doubt of law and doubt of fact. Doubt of law is had when there is doubt about the existence, sense, extension, or cessation from within of a law or disposition; for example, if there is doubt whether it is licit to paint on a feast day. Doubt of fact obtains when there is doubt about a particular fact or thing on which the application of a law or disposition to a particular case depends; for example, if there is doubt whether someone has fulfilled the law or is excused from the law. Yet authors do not agree in delineating doubts of law and of fact.

IV. Probability, or a probable sententia (opinion),² is taken by different persons in a different sense. Some call that opinion probable which rests on a grave foundation, even though perhaps on a foundation certainly less grave than the foundation of the opposite opinion; so the Probabilists. Others require that it rest on a foundation equally or almost equally grave as the opposite; so St. Alphonsus (Dell' uso moderato, c. 5, n. 25). Others require a foundation so grave that it merits the assent of a prudent man; this belongs only to the more probable opinion; so commonly the philosophers.³ An opinion thinly or doubtfully probable is not called probable except improperly.

A probable opinion is distinguished:

1. Into probable absolutely, or in itself, and probable comparatively, or relatively, according as it is probable viewed in itself alone or compared with the opposite. What is comparatively probable is either far more probable, or most probable; or certainly, or much, more probable; or equally, or almost equally, probable; or, as others add, certainly, or much, less probable.⁴

2. Into probable in the logical sense and probable in the ethical or practical sense. Probable in the logical sense is what has grave reasons, or reasons fit for proving. Probable in the ethical sense is what has reasons so grave that, at least by force of a reflex principle, it can direct actions, or be approved for practice.

3. Into probable intrinsically and probable extrinsically. An opinion is called probable intrinsically if it is probable because of intrinsic reasons; probable extrinsically if such great extrinsic authority supports it that, because of that authority, it is prudently held as intrinsically probable. From these things it is clear that extrinsic probability is resolved into intrinsic probability. Besides, concerning extrinsic probability, first note proposition 27, condemned by Alexander VII: "If a book belongs to some junior and modern author, the opinion ought to be judged probable so long as it is not established that it has been rejected by the Holy Apostolic See as improbable."⁵ Then observe these things:

a) "The authority of writers must be estimated not from their multitude, but from their weight; so that the authority of few, or even of one doctor endowed with special knowledge and piety, is sometimes to be preferred to many others" (St. Alphonsus, Diss. de usu mod. op. prob., n. 88, year 1757).⁶

b) The authority of St. Thomas and St. Alphonsus is very great. That St. Thomas is to be preferred to all others, no one today will deny. Moreover, from the various ecclesiastical documents by which the doctrine of St. Thomas is celebrated and inculcated in an entirely singular way, it is enough to recall to mind the encyclical Aeterni Patris (4 Aug. 1879), the Motu Proprio of Pius X, De Studio doctrinae S. Thomae in scholis catholicis promovendo (29 Jun. 1914), and canons 589, § 1 and 1366, § 2.

The very great authority of St. Alphonsus is clear both from the fact that he was raised to the dignity of Doctor of the Church,⁷ and from the many, and singular, praises by which the Church has not ceased to adorn and commend his doctrine.⁸ Hence in controversial matters those authors should be consulted cautiously who easily withdraw from the doctrine of St. Thomas and St. Alphonsus, and who are struck by these words which Mercurelli, at the command of Pius IX, wrote back to Vitozza, who had defended the doctrine of St. Alphonsus against Ant. Ballerini: "His Holiness judged it commendable that you undertook to defend the praises bestowed by the Church upon the doctrine of St. Alphonsus, and that you took pains to meet the malice of those who, abusing the dispositions instituted concerning that same doctrine, tried to depress it."⁹

c) Concerning the manner in which St. Alphonsus gives his judgment about the value of opinions, it is useful to note these things:

(alpha) Generally, for him that opinion is practically probable which he calls probable.

(beta) If he calls one opinion more probable and another probable, he understands them as doubtfully more probable and doubtfully less probable, so that the latter too is held by him as practically probable.¹⁰ If concerning some opinion he says, "It is said not improbably," or "It does not seem improbable," or "Authors say probably," or, for example, "Lugo probably says," then regularly he holds the opinion in question as practically probable. If, once the doctrine set forth has been proved, he adds, for example, "Lugo observes," commonly he approves such an observation.

(gamma) If he writes, "The Doctors say that it is probably licit," from this it is not certainly clear what he himself thinks. If he calls certain opinions neither probable nor improbable, he keeps silent about his judgment concerning them. If he calls one opinion more probable, but gives no judgment about the opposite, or says of it, "I do not dare to condemn it"; "I do not dare to call it improbable," he does not therefore pronounce it practically probable, but leaves the matter to the judgment of others (Preface of St. Alphonsus, bk. V, n. 76).

(delta) If he calls some opinion truer, far, much, notably, certainly more probable, or more common and more probable, he does not hold the opposite as sufficiently founded.

(epsilon) If he calls an opinion common or more common, and gives no judgment about the opposite, the former commonly must be called his own.

Finally, if there is doubt about the doctrine of the holy Doctor, sometimes the doubt can be resolved from a comparison of different works and places.

¹ But if St. Alphonsus (I, 20) states that positive doubt is had "when for each part, or at least for one, there is a grave motive," he takes the word "doubt" in the broader sense, insofar as it includes both strict and broad doubt.

² It is better called an opinion (sententia) than an opinion (opinio), because opinio designates a state of mind.

³ Cf. De Minusprobabilismo, pp. 14-17.

⁴ An opinion which by some is called the only probable one falls into an opinion certain in the broad sense.

⁵ Denzinger-Bannwart, n. 1127.

⁶ Among grave authors St. Alphonsus counts: Suarez, Soto, Azor, Canus, Sylvius, Cajetan, Banez, Navarrus, Paludanus, Toletus, Sylvester, Lessius, Molina, Sanchez, Angelus, Vasquez, Armilla, Valentia, Layman, de Lugo, Castropalaus, Bonacina, Emmanuel Sa, Pontius, Cabassutius, Collet, Roncaglia, the Salmanticenses, Petrocorensis, Abelly, Cardenas, Coninck, Gamachaeus, Isambert, etc., besides St. Thomas, St. Bonaventure, St. Antoninus, and Scotus, whose authority indeed must be preferred to others (cited dissertation, loc. cit.).

⁷ This dignity, according to the doctrine of Benedict XIV, "does not pertain to doctors who have been in the Church, but to doctors of the Church itself" (De Serv. Dei beatif., etc., bk. 4, p. 2, c. 11, n. 11). For it, as the cited author teaches, there are required "eminent doctrine, notable sanctity of life... and besides this, the declaration of the Supreme Pontiff or of a General Council legitimately gathered" (loc. cit., n. 13).

⁸ It is pleasing to report some excerpts from certain ecclesiastical documents: 1. The Sacred Penitentiary on 5 July 1831 responded that a confessor is not to be disquieted who in the practice of the Sacred Penitentiary follows all the opinions of St. Alphonsus, although he does not read the works of the blessed Doctor except to know his doctrine accurately, without weighing the arguments or reasons on which the various opinions rest. Yet you should not apply these things to opinions which are sufficiently established to be opposed to declarations of the Church, or which someone, after perhaps making inquiry and taking all things into account, judges to be certainly less probable. 2. The Sacred Penitentiary on 19 Dec. 1855 responded to a certain professor that, notwithstanding his oath of following Probabiliorism and the opinions of the Probabiliorists, he could "follow and publicly hand on in all things the doctrine of St. Alphonsus de Ligorio." 3. The decree Urbis et Orbis, dated 23 March 1871, concerning the concession of the title of Doctor: "He (St. Alphonsus) dispelled and drove away the darkness of errors widely diffused by unbelievers and Jansenists, by learned works, and especially by treatments of Moral Theology. Besides this he clarified obscure things and explained doubtful ones, since among the tangled opinions of theologians, whether laxer or stricter, he paved a safe way by which the directors of the souls of the Christian faithful could walk with unoffending foot." 4. The Apostolic Letter in the form of a Brief, dated July 1871, concerning confirmation of the title of Doctor: "Intending his mind solely toward the glory of God and the spiritual salvation of men, he wrote very many books, filled with sacred learning and piety, whether amid the tangled opinions of theologians, both laxer and stricter, for fortifying a safe way by which the directors of the souls of Christ's faithful could walk with unoffending foot, or for informing and instructing the clergy." 5. Finally, the Congregations in their responses, repeatedly and expressly, referred questioners especially to the doctrine of St. Alphonsus (De Minusprobabilismo, pp. 46-48).

⁹ Nouv. Rev. theol. VII, p. 98.

¹⁰ Cf. De Minusprobabilismo, pp. 64-65.