Summa summae S. Thomae, Tomus II

In a twofold way we can conform to conscience: negatively, by not acting against it; positively, by acting according to it.

I say 1°: It is never licit to act against conscience, whether prohibiting or commanding, whether true or erroneous, even if it err vincibly; so that, if conscience dictate something to be prohibited, that cannot be put into act, and if it dictate something to be commanded, that cannot be omitted.

This is common opinion with the Author¹.

It is proved 1° from that of the Apostle ad Rom., XIV, 23: All that is not of faith is sin. For by faith the holy Fathers and interpreters commonly understand conscience.

It is proved 2° by reason². 1° Conscience is the proximate and immediate rule of human acts, namely inasmuch as it intimates or applies the law here and now commanding or prohibiting, whether because by force and name of law it prohibits or commands this act, although perhaps the law neither prohibit nor command it. Therefore to act against conscience is to act against the law actually binding, at least judged such; which cannot come to pass without contempt of law. 2° He sins who wills sin and is allured by it³. But he who acts against conscience, even erring, wills sin. Therefore. — Proof. of the minor. He wills sin who does what he judges to be sin. But he who acts against conscience does what he judges to be sin. Therefore.

I say 2°: We are bound not only not to act against an invincibly erroneous conscience, but we are bound absolutely to act according to it, while it dictates something to be done as of precept⁴.

It is proved: 1° Because omission of the act which invincibly erroneous conscience dictates to be of precept is no more from faith than the doing of the act which it dictates to be prohibited. 2° Because not to act according to invincibly erroneous conscience commanding something is to act against it: thus, e.g., if conscience dictate to thee invincibly that thou must lie in order to save the life of thy neighbor, if thou act not according to it by lying, by this very fact thou actest against it. But from the preceding conclusion it stands that it is not licit to act against an invincibly erring conscience. Therefore.

[ Not only he who acts with an invincibly erroneous conscience does not sin, but also, more probably, acquires merit. The reason is, that to pronounce some act good, at least inadequately, it suffices that it be directed by the dictate of reason and prudence. Since therefore one who acts prudently acts, without doubt he ought to merit on account of the good end which he intends and by whose power he acts, namely the glory of God or charity toward neighbor, etc.; just as, on the contrary, he demerits who does a work materially good but apprehended as evil, on account of the evil end unto which it is directed. This is drawn from this principle, that, if integrally or adequately, that is materially at once and formally, acts are specified by object and end; nevertheless, under the latter respect, their morality is determined by end alone, as the Angelic Doctor teaches, Ia IIae, q. 1, a. 3, c.: « Moral acts properly take their species from the end. » Whence he concludes, Quodlib. II, a. 27, c.: « A human act is judged virtuous or vicious according to the good apprehended, into which the will tends, and not according to the material object of the act. » And herein he consents to Augustine saying lib. II de Moribus Ecclesiae et Manich., c. 13, n. 27: « If the end to which the things we do are referred, that is for the sake of which we do whatever we do, have been not only blameless but also laudable, then at length our deeds also are worthy of some praise. » To which accords Bernard in lib. de Praecepto et Dispensat., c. 14, n. 41: « And indeed, he says, I should call worthy of praise pious intention alone, nor shall good will itself be plainly defrauded of due recompense even in a work not good. » ]

I say 3°: More probably we are bound to act according to a vincibly erring conscience commanding something to be done, not absolutely, but conditionally and on the hypothesis that it be not laid aside, as it can and ought to be laid aside. It is the opinion of John of St. Thomas, Serra and many others, against Sylvius and many others.

It is manifest by the same reasons: both because omission of the act which erroneous conscience dictates to be of precept is not from faith; and because not to act according to a vincibly erring conscience commanding something to be done is to act against it, as I was just now saying of invincibly erring conscience. Therefore.

You will say: One can and is held to lay aside that conscience. Therefore he is not held to act according to it. Indeed he can and is held to lay it aside; but, if he lay it not aside, what must he do? In this supposition alone our conclusion runs. And we say that he is held to follow it, because he cannot act against it; but he would act against it if he did not follow it. — Thou wilt infer: Therefore he will be bound to sin, because he sins by following it. So it is. He will be bound to sin, not absolutely, but from a supposition voluntary on his part, which he can take away by laying aside his conscience. Which is not inconvenient.

You will ask 1° how he who labors under vincibly erroneous conscience ought to lay it aside.

I answer. that he ought to lay it aside with prudence and maturity, lest, if he lay it aside rashly, and perhaps the conscience which he suspects to be erroneous be not erroneous, he expose himself to danger of doing ill what conscience prohibited, or omitting ill what it commanded. He ought therefore to employ humble prayer to the Father of lights, examine the whole matter exactly, consult books or learned men, and employ such diligence as prudent and upright men are wont to employ in weighty affairs. Speaking regularly, however, there suffices for the unlettered, indeed also for scrupulous lettered men, the judgment of pastor, confessor, or superior, saying that the conscience is erroneous; because by right it is presumed that God denies not to those whom he has set as rectors of others the light necessary for ruling them, while they themselves lack it.

[ These things indeed are true regarding him who here and now in any way advertises or suspects the necessity of inquiring into the licitness of an action before he put it into act. But it can happen that, even if the error be truly vincibly contracted, because it was formerly incurred culpably, the agent in the present neither adverts to it nor suspects it. This happens to a confessor who once cultivated theology insufficiently, or too long neglected its study through negligence. Of such a confessor St. Thomas most rightly says, q. 17 de Veritate, a. 8, ad 8, that « he is never excused from sin, » whether he act according to conscience or against it. And the reason of this decision is evident, because there remains the sin, however old it be supposed, of culpable ignorance of those things which one is held to know, that he rightly fulfill the duties of his own state. This guilt is indeed not incurred at the instant at which one is about to act, but it is a fault of diligence formerly omitted and independent of present action. Whence the gravity of this sin is not drawn from the action now to be put forth, but must be estimated from the common principles concerning sins of ignorance. Hence is also seen why, in this case, he is more guilty who acts against conscience than he who acts according to it. For the latter has only the aforesaid guilt of ignorance; the former truly, besides this, adds now another guilt of an action put forth against conscience, from the principle enunciated by the Apostle, Rom., XIV, 23: All that is not of faith is sin. — If he who labors under such ignorance retract the admitted fault through congruent penance and added diligence, as is fitting, he is to be equated with him who lives in invincible ignorance. ]

You will ask 2° whether a subject can obey a superior against conscience dictating that it is illicit here and now to obey him.

I answer. in the negative; because, as was said, it is never licit to act against conscience, and it binds by force of divine precept, which outweighs the precept of man. Yet if it be vincibly erroneous, the subject ought to lay it aside and obey.

Yet beware lest here thou confuse conscience about the liceity or illicenity of obedience to be rendered here and now to a superior, with doubt or speculative judgment about the injustice of his precept, as certain men seem here to confuse, and therefore treat and resolve this question very perplexedly. These things are wholly diverse, and a subject can doubt, or even judge more probably speculatively that the superior commands ill, and nevertheless practically judge himself held here and now to obey him. That this may be explained,

You will ask 3° whether a subject doubting or judging more probably the precept of a superior to concern something illicit, can and ought obey him.

I answer. A subject who is not certain, but doubts, or even judges more probably the precept of the superior to concern something illicit, speaking regularly, can and is held to obey him, forming for himself a morally certain conscience of the liceity of his obedience from the following principles.

1° The holy Fathers teach that one must obey a superior when it is not certain that what he commands is against God. Aug., lib. XXII contra Faustum, cap. 75: « A just man, he says, if perchance he serve as soldier under a king, even a sacrilegious one, could rightly, at his command, wage war, observing the order of civil peace; of which it is certain either that what is commanded is not against the precept of God, or that it is uncertain whether it be. » St. Bernard., lib. de Praecept. et Dispensat., c. 9, n. 21:

« Whatever man commands in God's stead, provided it be not certain that it displease God, is altogether to be received no otherwise than if God command it. » St. Bernardine of Siena, in the dialogue on Obedience: « A subject reasonably doubts whether what is commanded be sin: is he then not held to obey the prefect? »

2° The superior has certain right of commanding, nor is he stripped of his right on account of the subject's doubt. Therefore the subject is held to obey him; for right of commanding and obligation of obeying are correlates.

3° From denial of obedience, while manifest cause cannot be assigned, authority is enervated in superiors, obedience perishes among subjects, quarrels and contentions are born between superiors and inferiors, and thus government is impeded in many things, with scandal of others.

From these principles therefore, although there remain a speculative doubt or more probable judgment about the dishonesty of the precept, which I suppose invincible, the subject can form for himself a morally certain conscience about the honesty of his obedience, thus discoursing: I can and am held to obey a superior when I am not certain that what he commands me is against God. But I am not certain that what he here and now commands me is against God. Therefore I can and am held here and now to obey him. The major is morally certain, from the principles posited. The minor is physically certain, and therefore also the conclusion, which is conscience, is morally certain.

I said, « speaking regularly; » because the conclusion admits exception, if namely from obedience there follow a graver inconvenience than from disobedience. For a superior is not judged prudent to will binding in these circumstances, otherwise he would abuse his right. And if he insist, ignorant perhaps of the inconvenience, the subject is understood to obey as much as he can and ought. Nor can it be said that he has certain right of commanding in these circumstances, but rather on the contrary it seems certain that he has it not.