Chapter II: On the Formation of a Certain Conscience for Removing Uncertainty

S. Th. II-II, q. 1, a. 4; q. 2, a. 1; q. 4, a. 8; Q. D. de Ver. 14, a. 1.

71. Various states of mind: doubt, suspicion, opinion, certitude. - Besides certitude, which is the state of a mind firmly adhering to one part totally and determinately, a threefold state of mind can be distinguished, with respect to adhesion or assent to the object: doubting or suspension of assent, - suspicion or inclination to assent, - opinion or assent, but not firm assent, because it is with fear of the opposite.

1. Doubt properly so called, or positive doubt, is the state of an intellect placed in equilibrium, which, namely, suspends assent and adheres to neither part, nor inclines more to one part than to the other, but wavers between the two on account of the apparent equality of reasons. It differs strictly from nescience, which is suspension of assent on account of a defect of reasons moving to assent, and which is improperly called doubt and is customarily called negative doubt.

2. Suspicion is the state of a mind inclining more to one part than to the other, without assenting to it, because for it there stands a reason, or an excess of reasons, a little greater than for the other.

3. Opinion is the adhesion of the intellect to one part without being totally determined to it, or the acceptance of one part with fear of the other, because there are sufficiently graver reasons for one part than for the other.¹

¹ Cf. II-II, q. 2, a. 2.

Since in human operable matters a little is reckoned as nothing,² because it helps or impedes little for obtaining the end, and therefore it does not much matter whether it is done thus or thus, for that reason slight reasons are reckoned as none, and a slight excess of reasons as none. Whence although psychologically they differ, nevertheless morally suspicion is judged doubt; positive doubt on account of slight reasons is judged negative; only doubt on account of grave reasons equal or almost equal on both sides is judged positive;³ opinion founded on graver reasons in such a way that against it there stand only slight reasons is judged practical certitude, to which it comes near and from which it is separated by a slight distance. Hence in practice there remain only doubt, opinion, and certitude.⁴

² "Reason takes what is slight as almost nothing," I-II, q. 14, a. 4. Cf. St. Alph., Th. M., book I, n. 55.

³ St. Alphonsus, Th. M., book I, n. 20; and the Dissertation of the year 1762.

⁴ Cf. Q. D. de Ver. 14, a. 1.

72. What probable opinion is. - Opinion is properly taken subjectively, and is a judgment by which we adhere to something as true, not firmly, but with fear of the opposite, because for it alone there stand grave reasons, or reasons sufficiently graver than for the opposite;⁵ whence although the truth is not manifested, nevertheless there is had a notable appearance of truth. Often, however, it is taken improperly, objectively, for the doctrine to which we adhere in this way; but this is not opinion, but that which we opine and approve by judgment, and therefore it is properly called probable or truthlike; hence such a doctrine is often called a probable opinion.⁶

⁵ We speak thus because of the manner of speaking of the equiprobabilists, who acknowledge only reasons a little graver and notably graver. They affirm with us that these latter found certitude broadly so called; but that reasons a little graver do not suffice for founding opinion, or the assent of one part with fear of the other, is manifest; whence in practice they do not distinguish opinion from certitude broadly so called. - But according to others, reasons can be so notably graver than the opposites that the intellect can adhere to them, although with fear of the opposite; yet not so notably that they constitute prudential certitude. Therefore, lest confusion arise, we abstain in the definition from the word "notably," and we say that opinion is founded on reasons which are sufficiently much graver than the opposites, so that the excess is not slight but grave, without however being altogether grave.

⁶ Thus passim in St. Alphonsus and recent authors.

Now probable is that which is worthy to be approved, which is apt to move a prudent man to assent and merits the assent of a prudent man; whence properly it is that for which there stand reasons absolutely grave and relatively graver than for the opposite, and therefore it is more often joined with truth than with falsity; otherwise it would not merit approbation, nor would it be worthy to be approved rather than the opposite, nor would it be like the true.⁷ Therefore only the doctrine more founded is probable in the strict philosophical sense; whence Aristotle (Top. I, c. 1): "Probable things are those which seem so to all, or to most, or to the wiser, and among these either to all, or to most, or to the most known."

⁷ This definition is rejected almost unanimously by the more recent Probabilists, indeed it is held to be something unheard of in Philosophy; according to them, probable properly is everything for which there stand grave reasons, even less grave ones. Yet our definition is generally admitted by philosophers of the Dominican school, "in which," as St. Alphonsus says, Th. M., book I, n. 80, "great doctrine has always flourished," indeed even by certain authors of the Society of Jesus, and it was commonly handed down by the philosophers of the middle age. That doctrine, says de Caigny, On the Genuine Moral System of St. Alphonsus, n. 263, "seems in no way to differ from the ancient definition of probable which the Angelic Doctor and other scholastics commonly handed down until the sixteenth century: which doctrine, like very many others, was rejected in the time of the false reformation; but in our days, like so many others, deserves to flourish anew in the Schools."

73. Opinion is an adhesion of the intellect commanded by the will. - Since the intellect does not have evidence of the thing, it does not adhere to it from the necessity of its nature, by which it would be carried to it without impediment, but adheres only dependently upon the free will, which moves it to assent (II-II, q. 1, a. 4). Namely, one thing is the judgment by which we affirm that on one side there are graver reasons and on the other side reasons are not present or are less grave: this judgment is necessary, because the intellect, sedulously comparing the reasons, cannot but see which are the graver; another thing is the judgment by which we adhere to the more founded part, and approve it and make it our own: this judgment is free from the motion of the will and is the judgment of opinion, while the former is presupposed so that the will may be able rationally to incline the intellect to adhere to that part.

Hence the will 1) can refrain from commanding assent, and thus will be the cause that the intellect suspends assent;

2. although it cannot directly compel the intellect to judge that there are grave or graver reasons, and yet to adhere to the less grave, nevertheless indirectly it can turn the intellect away from consideration of the graver reasons and bend it to consider the less grave reasons, which are also worthy of a certain attention and consideration.⁸ Indeed,

⁸ The reason why the will cannot directly determine the intellect to adhere to the less founded part is that the intellect is not, like the will, a free power, but a necessary power, not something blind, but a spiritual light; whence it necessarily sees the greater likelihood and tends toward it. Even Fr. Arendt was compelled to concede this in his Critique of the Apologetic Work of Fr. de Caigny, p. 23: "Therefore, in order that the will may obtain the assent which it wishes, it will be necessary for it somehow finally to avert the attention of the mind from contrary motives, and to see that the memory of the probability previously judged in those motives is erased, and at the same time that weights from elsewhere are increased for the part which the will itself favors." In this indirect way, namely, by causing the opposite reasons, in the course of time, to vanish totally from the mind through forgetfulness, the will can move the intellect to adhere to less grave reasons. - But what he adds on p. 40, that the will, on account of an extrinsic reason, for example the authority of another, can command the acceptance of one part which of itself is equally probable as the other, can be admitted if that authority increases the probability of one part; or it must be understood in this sense, that that authority is a sufficient motive for judging that following that part is good in practice; not however that it is a sufficient motive for judging that part to be theoretically more truthlike. For the intellect necessarily sees each part to be founded upon equal reasons, and consequently necessarily judges that neither is to be adhered to as true or more founded, and it tends toward neither. "When," says St. Alphonsus, Th. M., book I, n. 71, "there is present on the other side an equally probable opinion, then on neither side can there remain any probability, or probable reason apt to draw to itself the prudent assent of a man; for from these equal properties nothing other than mere doubt results... St. Thomas clearly teaches this, De Ver., q. 14, a. 1... When two probable opinions occur, they suspend judgment just as if no probability existed on either side." And n. 78: "Where two opinions concur equally probable, neither remains probable, but only doubtful."

3. it can apply the intellect now to one part, now to the other, so that it wavers between the two. In these three cases the will does not act conformably to the nature of reason, nor therefore rightly;⁹ yet because it can do this, therefore

⁹ "As often as it certainly appears to the intellect that truth stands much more for the law than for liberty, then the will cannot prudently and without fault adhere to the less safe part: since in that case a man would act not resting upon his own judgment, but rather through a certain effort which he would impose by his will upon the intellect, so that it might be removed from the part which appears to him much more truthlike," St. Alphonsus, Th. M., book I, n. 56. And n. 69: "Another principle of certain probabilists is this, that when each opinion is probable, a man suspends judgment concerning the safer opinion, and, leaning upon the probability of the benign opinion, acts. But Fr. Berti justly also rejects such a principle; for it by no means can render us certain concerning the honesty of the action, since this suspension of judgment is merely voluntary; whence it cannot excuse from ignorance being truly vincible, and therefore in this way doubt certainly cannot be put aside." - And Arendt himself admits this, o. c., p. 22: "The will indeed will rightly and without any fault move the intellect to give assent to the thing itself, if it has not commanded an assent firmer than the motives are able to require; but culpably if it has induced the intellect to assent to the thing itself either more firmly than the motives bear, or without any fear, and hence as if the thing were objectively evident."

a) opinion is sometimes called doubt broadly so called;¹⁰

¹⁰ Cf. St. Alphonsus, Th. M., book I, n. 67.

b) the dwelling of the intellect in considering less grave reasons is by some improperly called opinion; whence

c) moralists are accustomed to speak of opinion as more, equally, and less probable.¹¹ For for them probable is taken in a broad sense and is everything which, if not worthy of proof, is nevertheless worthy of attention and consideration, namely, that for which there stand grave reasons, even reasons less grave than for the opposite.

¹¹ The manner of speaking can also be explained in an objective sense concerning an opinion which exists among different persons, so that the opinion of certain theologians seems more probable to someone and therefore is his opinion, and the opinion of others appears to him equally or less probable than the other, and is not his opinion. The old writers are to be understood thus.

74. Various degrees of probability. - By reason of the gravity of the foundation or of the firmness of the motive, the probable has several degrees, so that it has so much more of probability as it has of gravity. And indeed:

a) If it is considered absolutely in itself, from its approach to the truth, three degrees are distinguished: truly and solidly probable - very probable - most probable, according as the reasons are grave - or very grave - or so grave that scarcely any prudent fear of the opposite remains.

Below true probability from a truly grave motive, there can be an imperfect appearance of truth from a doubtfully grave motive or from slight motives which do not merit the assent of a prudent man: this they improperly call doubtful, or light or slender, probability.

b) Comparatively to the opposite, however, there are distinguished: uniquely probable and not probable - probable and equally probable - more probable and less probable - indeed also much, very, notably more probable, and much less probable.

But in order that the reasons upon which probability is founded may be rightly estimated, it is necessary that they be considered both absolutely, so that according to themselves they are grave, and relatively, i.e., with attention to the reasons in the opposite direction:¹² for it can happen that a reason grave in itself, comparatively to another, is judged slight, for example if the contrary is very notably more probable,¹³ or even none, if the contrary is certain.¹⁴

¹² Concerning those who would not weigh opposite reasons, Lehmkuhl writes, Th. M., book I, n. 190: "He who is accustomed so rashly (namely, by not weighing the reasons of the contrary opinion) to pour forth his opinions... does not deserve the name of theologian."

¹³ Then the first sentence can only be slenderly and doubtfully probable.

¹⁴ For example, from a decree of the Church. Then from the motives there arises a difficulty perhaps here and now insoluble, but not probability.

Yet it does not seem to be denied that, even in moral matter, there can be opposite reasons and sentences which are truly grave and solidly probable, not only because they appear equal to each other and equally probable, but even when one seems more founded or more probable, the other less founded and less probable, without however the former being judged much, very, or notably more probable. And then the intellect, in adhering to the more probable sentence, can and must at the same time judge that the other, to which it does not adhere, is founded and in some way, though less so, probable.

By reason of security, the probable is safe, safer, or less safe, according as it wholly removes, or more, or less removes, the danger of sinning, either formally or even materially.

And so safer and more probable do not sound the same. Probability is said from the appearance of truth, security from the removal of danger, in this case of sin; whence the more probable is that which has a greater appearance of truth than the opposite, the safer that which more removes the danger of sinning even materially, or of transgressing the law. Therefore, since that which favors the law removes the danger of sinning more than that which favors liberty, for that reason that part which favors the law is safer and that which favors liberty is less safe. Hence the safer can be less probable, for example, if it is less probable that an obligation exists; - and on the contrary the more probable can be less safe, if it is more probable that the obligation does not exist. Thus, for example, the opinion of St. Bonaventure, establishing that after sin confession must be made at once, is safer; the opinion of St. Thomas denying this is more probable.

75. Various species of certitude. - Certitude A. is one kind when it is strictly so called, fixed, demonstrative, and philosophical or speculative, which excludes every fear of erring, and therefore is the determination of the intellect to one thing.¹⁵ This, on the part of the negative element, i.e., insofar as it excludes every doubting or fear, does not admit degrees but is in the indivisible; - on the part of the positive element, i.e., insofar as it adheres firmly to the object, it is greater or lesser. And indeed on the part of the cause, i.e., by reason of the firmer motive and of that to which error is more or less repugnant, natural certitude¹⁶ is metaphysical, physical, and moral, according as it is founded in the essential necessity of things (for example, the principle of causality, God exists), in their natural necessity (for example, from hydrogen and oxygen water is produced), or in the testimony of others which in the case is certainly demonstrated not to err (for example, the Chinese empire exists). But on the part of the subject, i.e., by reason of the manifestation of the object or of clarity, it is evident or intrinsic, which necessitates the intellect, and inevident or extrinsic, which does not necessitate and is taken from the authority of others.

¹⁵ "The firmness of adhesion of the cognitive power to its cognoscible." St. Thomas, II Sent., d. 26, q. 2, a. 4.

¹⁶ We are speaking only of natural certitude, and we abstract from the supernatural certitude of faith, which exceeds even metaphysical certitude. I, n. 721.

B. Another kind is broadly and improperly so called, conjectural or probable, which does not exclude every fear, but only the reasonable and prudent fear of erring. This is not strict certitude, because it does not prevent every fear, but is the greatest probability; and therefore even on the part of the negative element it admits degrees and is greater or lesser, more or less perfect, according as it excludes doubting more or less. By most it is called moral; for it suffices in moral matters, and moreover, although not physically, nevertheless morally it determines the intellect to one thing, insofar as there is lacking every serious reason for doubting which moves to the opposite. Whence although in practice it is equivalent to certitude, because it suffices for acting rightly and prudently, nevertheless it renders us morally, i.e., almost and equivalently, certain, rather than being true moral certitude. And therefore, that it may be distinguished from moral certitude strictly so called or historical certitude, it is better called practical and directive, because it suffices for acting and directing our acts; or prudential, because it suffices that men act prudently.

This, by reason of the principle or cause, is direct if it arises from proper principles or reasons taken from the very thing to be examined, for example from comparison with a particular law, from the institution of Christ, etc., for instance whether such a work is servile, or such a manner of baptizing is good; - or indirect, if it arises from principles extrinsic to the thing, for example from authority, or from general and higher principles of practical reason called in to aid in having a certain norm of acting; for instance: even if the work is servile, it is licit for me because the pastor said so; even if the manner of baptizing is perhaps good, it is illicit because it exposes the sacrament to the danger of nullity. These principles are called by theologians indirect or reflex, because the intellect, reflecting upon its state of uncertain conscience, uses them to render it certain by a reflex judgment.¹⁷

¹⁷ St. Thomas too acknowledges indirect principles, in the case in which gnome and epikeia intervene. Cf. I-II, q. 57, a. 6, ad 3; II-II, q. 120, a. 1 and 2; q. 51, a. 4; q. 80, a. 1, ad 4 and 5.

76. State of the question. - When diligent inquiry and deliberation have been completed, for forming conscience concerning the morality of an act in particular, therefrom a threefold state or species of conscience can arise directly on the part of the subject, or of adhesion to the object and of certitude: doubtful, opinative, or certain conscience, according as the reasons appear morally equal, - or on one side are graver or more probable, - or convincing.

Now a) if conscience is sufficiently certain, it can be a prudent rule of acting; but because b) absolute or direct certitude is for the most part impossible, it does not always easily appear whether there is sufficient certitude; c) but if conscience is not sufficiently certain, further inquiry must be made, provided there is a founded hope of arriving directly at certain conscience, because we must attend to this with every moral diligence (n. 49); but if d) it now appears morally impossible, it must be seen whether it is possible to arrive at indirect certitude from a reflex judgment. Hence it is asked:

1. whether there is an obligation of forming certain conscience, and what certitude is sufficient so that conscience may be a rule of acting prudently and practically certain;

2. how in a case of opinion or doubt, according to prudence, someone can form for himself an indirectly certain conscience, which may be a rule of acting prudently and practically certain.

77. Various solutions and diverse systems of theologians. - For solving the aforesaid questions, various systems have been devised by theologians:¹⁸

¹⁸ Absolute tutiorism or Rigorism says that it is always imprudent and illicit to follow the part favoring liberty or the less safe part, unless it is certain. Hence the saying: Safer or certain; or: Always the safer.

Thus Sinnichius, a doctor of Louvain (d. 1666), is said to have taught in the book Saul Ex-Rex I, c. 95; likewise Wendrochius (pseud. Peter Nicole) and several Jansenists. This was condemned by Alexander VIII in prop. 3: "It is not licit to follow an opinion even the most probable among probable ones."

2. Mitigated tutiorism says that it is always imprudent and illicit to follow the less safe part, unless it is most probable. Hence the saying: Safer or most probable.

Thus several doctors of Louvain in the eighteenth century: Steyaert, van Opstraet, Daelman, Henry of St. Ignatius, Dens; likewise Fagnanus, Habert, Cardinal Gerdil.

3. Probabiliorism says generally that it is imprudent and illicit to follow the less safe part, unless it is manifestly and solidly more probable than the opposite. Whence the saying: Safer or more probable.

Thus several older Thomists, such as Conrad, Sylvester, Cajetan, and after the year 1656 until the approval of the doctrine of St. Alphonsus, Dominicans generally;2 also several from the Society of Jesus, such as Thyrsus Gonzalez (f. 1681), who thus taught with Innocent XI yielding consent.3

To this is added the system of compensation, which says that the more probable is to be followed unless there is an excusing reason which compensates the probability of transgressing the law, and indeed one proportionately grave in comparison with the gravity of the law and with its greater probability.

Thus Potton, Manier, Laloux, Lehu, Prummer, Mc. Donald.

4. Equiprobabilism says generally that it is prudent and licit to follow the less safe part which is equally or almost equally probable, because the law does not oblige unless at least it is certainly more probable. Hence the saying: The more benign, provided it is equally probable.

More recent equiprobabilists, however, after St. Alphonsus, add a restriction to the principle and say that it is licit in the case in which there is doubt about the existence of the law and liberty possesses; but illicit, on the contrary, if the law possesses and there is doubt about its cessation, because it does not cease to oblige unless it has more probably ceased. Hence the saying: The part for which possession stands, provided it is equally probable.

Yet this restriction is not essential to the system, nor proper to it, since certain probabilists also make it.

Certain older writers already seem to have adhered to equiprobabilism; some theologians from the seventeenth century proposed it systematically; St. Alphonsus especially defended it, and many followed him, even several in the school of St. Thomas.

5. Moderate probabilism says generally that it is prudent and licit to follow the less safe part solidly and truly probable, even if the opposite is certainly more probable. Hence the saying: The more benign, provided it is solidly and certainly probable.

Thus B. de Medina in the year 1577, and after him theologians generally, even in the school of the Thomists, from the end of the sixteenth century until the middle of the seventeenth century; and especially the theologians of the Society of Jesus; but from the middle of the nineteenth century also many others.

6. Laxism or laxer Probabilism says that it is always prudent and licit to follow the less safe part even if slenderly or doubtfully probable. Hence the saying: The more benign, provided it is in some way, even doubtfully, probable; or: The more benign, unless the law is truly certain.

Thus in the seventeenth century several from the Society of Jesus, such as John Sanchez, Leander, St. Bauny, Escobar, Tamburini, M. Moya; also Diana, the Theatine, who was called "the lamb who took away the sins of the world"; likewise Caramuel, the Cistercian, prince of the laxists. It was condemned by Alexander VII in prop. 27, and by Innocent XI in prop. 1, 4, 21 and 64.

1. A brief historical excursus concerning the systems is placed by way of appendix at the end of the volume.

2. In the general chapter of the Order of Preachers of this year, it was decided that thereafter the theologians of the Order should attack the laxer opinions. But they did not attack only Laxism; from this moment they also positively defended Probabiliorism, at least generally, although this had not been commanded. After the laudatory approvals of the doctrine of St. Alphonsus, several now follow equiprobabilism, while some teach the system of compensation.

3. You will find the system well expounded in Billuart.