Chapter II. On Certain and Doubtful Conscience

Certain conscience is that by which someone firmly and without fear of erring judges something to be good or bad.

Although certainty is distinguished in three ways among philosophers, that which is called moral is chiefly considered by moralists. This certainty, which rests upon the laws by which men are ruled in their acts, is subdivided into perfect and imperfect. The former is that which is so founded upon moral laws that the proposition is clearly perceived to be unable to be false. This is reduced indirectly to metaphysical certainty. The latter is that which belongs to those propositions in which it is not absolutely repugnant that there be error, although this can happen most rarely. This admits various degrees.

Doubtful conscience is that which remains suspended concerning the honesty of an action; for doubt is the suspension of assent between opposites.

Multiple doubt is distinguished, namely: 1st, positive or negative; the first is had when the intellect suspends assent on account of grave reasons for doubting, or at least reasons apparently such; but the other when assent is suspended on account of a defect of motives; 2nd, of law or of fact, according as it is concerned with the existence of a law, or its obligation, or with some particular fact; 3rd, speculative or practical, according as it is concerned with the abstract cognition of truth and in common, or with truth which here and now is ordered to work.

Only certain conscience is the right rule of morals, and therefore it is never licit to operate with a practically doubtful conscience. The reason is both because, according to the Apostle, Rom. xiv, 23: "all that is not from faith is sin"; and because the agent with a conscience not certain voluntarily admits the danger of transgressing a precept, and therefore, by virtually consenting to its violation, formally sins. But morally certain conscience, even imperfect, suffices; because only that certainty is required which alone for the most part can be had; otherwise the rule of acting, to which man is proximately subject, would be very little accommodated to the human condition. Cf. Baller., note (a), p. 41.

You Will Resolve. 1st. As often as someone doubts whether the act which he is about to place here and now is licit or not, he is bound to apply diligence congruent to the gravity of the matter and the condition of person and place for the inquiry of truth; let him consult upright and skilled men, investigate their practice, and weigh the reasons with the sole zeal for truth; otherwise he exposes himself to the danger of violating the law from negligence in inquiry, and by that very fact sins.

2nd. If he cannot inquire, nor by himself is able to weigh the reasons of each side, nor in another way, for example through reflex principles, free himself from doubt, let him embrace the safer part; because otherwise he would act in practical doubt, that is, with a conscience truly doubtful and without any certain judgment concerning the honesty of the action.

3rd. He who, after diligent and sufficient inquiry has been completed, still doubts whether there is a law commanding or prohibiting, is not bound to obey this law, if nevertheless he can form for himself a conscience from a reflex principle, namely that a law which cannot be found cannot oblige, as will be said below, where probabilism is treated.

4th. Merely negative doubt is to be held as nothing, because it is founded upon no reason at all, or upon a very light one. Therefore, even if it remains, because it cannot bring it about that the opposite moral certainty is overthrown, nevertheless the obligation presses, or liberty stands, according as it existed before. But if a prudent suspicion of error, resting upon a grave motive, arises for you, the doubt ceases to be merely negative, and you are bound to inquire. And so, when hereafter cases of negative doubt occur, you will easily dissolve them, this rule having once been established, and therefore we shall attend only to positive doubt. Cf. St. Alphonsus, n. 24.

Question 1. Does he who operates with practical doubt concerning the gravity of sin sin gravely?

Response. Affirmatively. For he who acts with a practically doubtful conscience, according to the common principles, sins in that species of sin, both moral and theological, concerning which practically, while he acts, he doubts. The reason is that he surely violates the grave obligation of taking care lest through voluntary ignorance or inadvertence he fall into transgressions of the law which could be grave.

Question 2. What is to be done in the case of a perplexed conscience, namely when someone, placed between two precepts, remains doubtful which of the two he ought to follow?

Response. 1st. Consult, if you can, a confessor or other prudent men, because in that case ignorance is vincible. 2nd. If you cannot consult and there is a necessity of acting, because the action cannot be suspended without grave harm, choose what seems to you the lesser evil, yet not so that you do evil, but so that you recede more from evil. Know, moreover, that the law of an inferior order ought to yield to the law of a superior order. 3rd. If each precept seems to you equally grave, choose anything, and you will not sin; for there is not given a necessity of sinning. Cf. St. Alphonsus, n. 10.