Article I: On the Rectitude of Conscience

St. Thomas, I-II, q. 19, a. 3, 5, 6; De Veritate, q. 17, a. 2, 3, 4; II Sent., d. 39, q. 3, a. 3; Quodlibet III, 26, 27.

206. Notions. - Conscience must be right. Now by reason of the object, or of conformity with the law, conscience is distinguished as twofold: true and erroneous, according as it dictates the truth of the thing or falsity. True conscience, namely, is that which from true principles dictates that something in particular is licit or illicit which really is such, namely, which is truly good or evil. Erroneous conscience is that which from false principles, nevertheless reputed true, dictates that something in particular is licit or illicit which really is not such, for example, that what in itself is good or indifferent is evil, or that what in itself is evil is good. It is erroneously vincible if it can be conquered by moral diligence, but voluntarily is not conquered, whether directly by design, or indirectly from negligence; invincibly, if it cannot be conquered by moral diligence, either because someone has in no way, not even confusedly, thought about the truth to be inquired into, or because, sincerely inquiring into the truth, he has not arrived at it. But if conscience errs from an error which before was vincible, but now is invincible, although the preceding error was a sin and so much graver as the greater evils foreseen as to follow from it were greater, nevertheless the actual judgment of conscience itself is truly invincible.

Now it is asked whether both consciences, true and erroneous, are a rule of acting and in some way sufficiently right. To solve this question, many have distinguished negative conformity and positive conformity with conscience, saying that every conscience always obligates lest we act against it, but that not every conscience, namely erroneous conscience, always obligates us to act according to it: negatively, namely, it is licit to act against no conscience, but it is not always required that we act positively according to it. But that distinction is generally useless: for one who does not act according to a conscience commanding and prohibiting, but does not do what it commands or does not avoid what it prohibits, by that very fact also acts against conscience, because he does what it prohibits or omits what it commands. Hence by equal reason, in the mode of one response, we shall answer both at the same time.

207. Principle I. True conscience is per se the rule of acting, so that if it is commanding or prohibiting, we are bound to conform ourselves to it both negatively, by not acting against it, and positively, by acting according to it.

It is said: a) per se, that is, from its nature, because it faithfully exhibits the law as it is in itself, whence it binds absolutely and in every event, and therefore an act conformed to it is per se good;

b) if it is commanding or prohibiting: for if it counsels or permits, to act against it is not illicit, because we are not bound to do or omit what is commanded or prohibited by no law; for conscience counseling binds us not to contemn it, not that we fulfill it. But we can always act according to a true conscience; indeed we also have the right so to act.

It is proved: 1) from Scripture, Rom. XIV, 23: Everything that is not from faith (uit goeder trouw, de bonne foi) is sin, that is, he who does not act from belief, persuasion, the judgment of conscience, sins, as the Fathers commonly understand.

2. By reason: conscience, because it intimates and applies the law, is the proximate rule of human acts, according to which their moral being is measured. But true conscience rightly applies the law, for it is a faithful herald. Therefore an act which departs from it is not conformable to the law but is morally evil. This is confirmed: true conscience is the law itself certainly known by us and applied to the act. But we are bound to follow the known law. Therefore.

208. Principle II. Invincibly erroneous conscience is per accidens the rule of acting, so that if it is commanding or prohibiting we are bound to conform ourselves to it both negatively, by not acting against it, and positively, by acting according to it.

It is said: a) per accidens, that is, not from its nature, because it is not conformable to the law, but by reason of ignorance, because it is believed to be conformable to it; whence it does not bind in every event but under a condition, if it endures and as long as it is not laid aside; and therefore an act conformed to it is good per accidens;

b) if it is commanding or prohibiting: for if it counsels or permits, to act against it is not illicit, because invincible error excuses from sin; nevertheless we do not have the right of acting according to it, because there is no right to follow error.

It is proved: 1) from the Scriptures: he who acts against an invincibly erroneous conscience does not act from faith or from persuasion, and accordingly according to the Apostle (Rom. XIV, 23) he sins. This is clearer from the context in which the Apostle, speaking of the eating of foods which in themselves are not evil but by many were erroneously held to be unclean, as if prohibited by the Mosaic law, teaches that those sin who truly think the eating illicit; for in v. 14 he says: I know and trust in the Lord Jesus that nothing is common (that is, unclean) through itself except to him who esteems that it is common; that is, I am certain that no food from its nature is unclean except for him who thinks that it is unclean. And in v. 23: But he who distinguishes, if he eats, is condemned, because not from faith; that is, he who doubts concerning the liceity of food, if he eats what he doubts to be unclean, is condemned because he has not acted from the persuasion (good faith) of conscience; a fortiori he who would eat what he certainly judged to be unclean. Similarly I Cor. VIII, 7: But some, with conscience even now of the idol, eat as idolothyte, and their conscience, since it is weak, is polluted. Likewise Gal. V, 3: I testify to every man circumcising himself that he is a debtor to do the whole law; that is, he who falsely thinks circumcision necessary for himself unto salvation, while this judgment of conscience remains, is consequently bound to observe the whole law. Whence Christ the Lord teaches that invincible error excuses, but not vincible error (Jn. IX, 41; XV, 24).

2. By reason: a) if invincibly erroneous conscience proposes something as the law of God, this is taken by the erring person as the law itself; therefore if he withdraws from this, he wills to withdraw from the law of God and thus contemns it, and acts badly. Thus, if someone falsely believed that the precept of a legate was the emperor's, by contemning the precept of the legate he would contemn the precept of the emperor (a. 5, ad 1 and 2).

b) A human act tends into the object as it is proposed by reason; therefore if erring reason proposes something as evil and man wills it, he does something which he judges evil, and thus is borne toward it under the aspect of evil and wills evil. And conversely concerning good. This is confirmed: the will is a blind power; whence its goodness and malice do not depend upon the object as it is in itself, but as it is proposed by reason and in the mode in which it is proposed (a. 5; Quodlibet III, 27).

209. Principle III. Vincibly erroneous conscience is not a legitimate rule of acting. For although it obligates that we conform ourselves to it when commanding, under the condition that it not be laid aside, nevertheless there is present the obligation of laying it aside if perhaps it is a cause of acting evil or of omitting a prescribed good; whence we can neither act against it nor according to it.

1. Let it not be said that in the case man necessarily sins, and is perplexed, not knowing what he should do in order to avoid evil. For, as St. Thomas says, q. 19, a. 6, ad 3: "Just as in syllogistic matters, when one unsuitable thing has been given, others necessarily follow, so in moral matters, when one unsuitable thing has been posited, others follow of necessity; as, supposing that someone seeks vainglory, whether on account of vainglory he does what he is bound to do, or omits it, he will always sin; nor nevertheless is he perplexed, because he can lay aside the evil intention. And similarly, supposing an error of reason or conscience which proceeds from ignorance not excusing, it is necessary that evil follow in the will; nor nevertheless is man perplexed, because he can recede from the error, since the ignorance is vincible and voluntary." Similarly in Q. D. De Veritate 17, a. 4, ad 8: "It must be said that he who has the conscience (vincibly erroneous) of committing fornication is not simply perplexed, because he can do something by which, when it has been done, he will not fall into sin, namely, lay aside the erroneous conscience; but he is perplexed in a certain respect, namely, while the erroneous conscience remains. And this is not unsuitable, that, something being supposed, man cannot avoid sin; as, when an intention of vainglory is supposed, one who is bound to give alms cannot avoid sin: for if he gives from such an intention, he sins; but if he does not give, he is a transgressor."

It is proved: 1) he who acts against such a conscience does what he judges evil and thus sins; but he who acts according to it does that which he cannot rightly judge to be good, because he has negligently judged concerning its morality, and therefore he exposes himself to the proximate danger of acting formally badly and operates rashly and acts badly. This is confirmed: for since he notices that there must be further inquiry concerning the truth, he voluntarily neglects this; whence he ought to fear that his action is evil, and cannot have security concerning its goodness (Jn. IX, 41; XV, 24).

2. He who does not lay aside a vincibly erroneous conscience by this very fact acts badly, because at least indirectly the evil which he operates is willed, since the ignorance itself (or erroneous conscience) from which it follows is willed. And indeed vincible ignorance does not excuse from fault; therefore it does not excuse from actual fault, if it is actually vincible.

210. Which conscience is right.

Many call right only true conscience. Others call invincibly erroneous conscience right if it is conformable to the law, as happens if it proceeds from speculative error, for example, the conscience of Jacob approaching Lia whom he thought to be Rachel, and not right if it is difform from the law, as happens if it proceeds from practical error, for example, the conscience of one who thinks theft is licit. Others call invincibly erroneous conscience right if it is logically deduced from a false principle, not right if it is illogically deduced. Finally, others call every invincibly erroneous conscience, as prudently formed, right, not simply, but in a certain respect, and with respect to the agent or as to us, in order to acting, because it is the right and legitimate rule of acting: for although speculatively it is false, nevertheless practically it is true and dictates practical truth, namely, that which truly is licit here and now, and conformable to right appetite or an honorable will: namely, it is true that in these circumstances this is licit or illicit for me. In other words, the dictate of such a conscience is from the right intention of doing good and avoiding evil, which is conformable to the higher true principle of morality: Good is to be done, evil is to be avoided, and in this way it is conformable to the eternal law of God. That this is true will appear more from the treatise on Prudence.

211. Corollaries.

From the aforesaid it is easily concluded:

1. That conscience binds: true conscience per se, and erroneous conscience until it is laid aside; but invincibly erroneous conscience excuses, not however vincibly erroneous conscience.

2. That man has an absolute right of following an altogether true conscience, and this is liberty which in the strict sense is liberty of conscience. As to invincibly erroneous conscience, although man in the internal forum can and must follow it, he does not have to this truly and properly a right, which is founded in objective relations of things, but only a reputed right; and especially he does not have an absolute right to follow it by an external act: for legitimate authority cannot indeed punish him who is proved to have followed the dictate of conscience, but can prevent him from following it in an external mode, for example, a Catholic State can prevent the exercise of heretical or infidel worship, although adherents not rarely follow the dictate of their conscience.

3. That there can be an act or sin against the law which is not against conscience, when the latter is ignorant of the law, but then the act is not formally but only materially evil. On the contrary, there can be an action or sin formally against erroneous conscience which is not against the law actually existing; nevertheless it is against the reputed law, whence, although it is not materially against the law, nevertheless it is against it formally, and it is against the eternal law, which dictates that one must not act against that which is thought to be commanded or prohibited. Finally, every formal sin against law is also against conscience.

Hence it is understood that conscience per accidens in some sense obligates more than the law of God: "Conscience obligates not by its own virtue but by virtue of the divine precept: for conscience does not dictate that something is to be done by reason of the fact that it seems so to itself, but by reason of the fact that it is commanded by God; hence per accidens, from the virtue of the divine precept, it obligates insofar as it dictates as commanded by God, and therefore conscience obligates more than the divine precept in whose virtue it binds. As is clear if the precept of a king did not reach the people except by means of some prince; if the prince said: this is commanded by the king, although it were not true, his dictate would obligate as the precept of the king" (II Sent. d. 39, q. 3, a. 3, ad 3).

4. Yet purely erroneous conscience, or erroneous conscience as such, cannot per se obligate, for obligation supposes a law not imaginary but existing and applied to the subject. Hence in the case of invincibly erroneous conscience we are obligated, not from the law which is not present and which conscience erroneously affirms, but from the higher certain principle of law, or from the universal natural law: Good is to be done, evil is to be avoided, which forbids acting against that which after diligent consideration we think to be good and commanded by God, or evil and prohibited. Hence such a conscience is in some way true, namely, practically, because it is true that, such a conscience standing, it is licit to act according to it; and it is right, as conformable to a right intention, which itself is right because conformable to a higher principle and thus to the eternal law.

This is to be applied to every erroneous conscience here and now invincible, even if it arises from ignorance antecedently vincible and culpable, provided it is actually invincible because it is not adverted to. Such a conscience was culpable in its cause, but it is a legitimate rule of acting here and now, and the action following from it is not culpable in itself, although it can be culpable in its cause.

1. In this sense, in a. 6, St. Thomas absolutely affirms culpability.

5. On the contrary, vincibly erroneous conscience can in no way be called right or true, because, with sufficient inquiry lacking, the agent cannot sincerely and in truth judge that the act is good or evil, nor sincerely will to do good and avoid evil. Therefore this conscience is simply erroneous.

212. Observation.

Concerning the mode of recognizing and laying aside an erroneous conscience, and concerning the obligation of undeceiving those who err in conscience, as also concerning the sin of acting against conscience, these things will be discussed in the treatise on Prudence.