Summa Theologiae Moralis, vol. I: De Principiis

On Impotence.

376. Impotence is the incapacity of the subject to fulfill the law : one is absolute when the prescribed work cannot be placed, whether it be corporal or physical when the physical power to place it is lacking, e.g. from defect of strength, of means, of liberty because of violence, external coercion, as with one sick and fixed in bed or incarcerated ; whether it be spiritual when the work cannot be placed without sin because of a higher law ; — another is moral when the law cannot be fulfilled without great fear or danger of grave harm or of bodily or spiritual inconvenience, which accidentally is joined with the fulfillment, e.g. if it requires extraordinary labor, or notably harms health or fortune, or gives occasion for scandal or grave scruples, or is an impediment to a great good, e.g. of an excellent work of charity not prescribed.

377. Rules about excuse because of impotence.

I. Absolute physical impotence always excuses from the observance of the law, because no one is bound to the impossible.

II. Absolute spiritual impotence excuses from the observance of the law, because no one is bound to evil.

III. Moral impotence, by reason of epikeia, regularly excuses from the observance of positive law, because law must prescribe acts morally possible ; hence the axiom : positive law does not oblige with grave harm or inconvenience extrinsic to it¹. How much difficulty however is required to excuse, is to be estimated morally from the importance of the law, the quality of persons, the circumstances of places, times, etc.

Exceptionally however it does not excuse :

1. of itself, by the force of the positive law itself, when the observance is necessary for the common good, which always takes precedence over private good ; thus e.g. even with danger of life the sacraments are to be administered to the dying by the parish priest, war is to be waged by soldiers ;

2. accidentally, by the force of natural law, when the violation would redound to contempt of God, of religion, of legislative power, or to grave scandal, e.g. the law of not celebrating without sacred vestments, the law of diriment impediments of matrimony, or the law of not eating meat if this were done out of hatred of religion.

378. He who cannot fulfill the whole law, is he bound to fulfill a part? — Resp. 1) he is bound to the possible part, if the law is morally divisible, the part is to some extent notable, and contributes to the end of the law, e.g. he who cannot fast is bound to abstain from meat. He who lacks a breviary is bound to the parts which he knows by memory or which are contained in the diurnal (prop. 34 damned by Inn. XI) ;

2. he is not bound a) if the law is at least morally indivisible, because it is impossible to observe even partially, e.g. fasting : thus he who cannot make a pilgrimage is not bound to begin the journey ; b) if the part is altogether trivial, so that it is considered as nothing, e.g. supplying the psalm iudica in Mass : thus if he would know little of the office, while lacking the breviary ;

c) if the reason of the precept is not preserved in the possible part, because this contributes nothing to the end ; e.g. he who cannot be present at the consecration is not bound to the rest of the Mass which is not prescribed except for the consecration.

He who seriously doubts whether he can observe the possible part, is not bound, because of the great inconvenience of the scruple.

379. Is it lawful to place an impediment to the observance of law? — Every precept in some way obliges, both to avoiding impediments and to removing those which hinder its fulfillment. Hence

1° to place impediments, whether proximate or remote, or not to remove them, is not lawful if it be done directly, i.e. with the end that the precept cannot be satisfied, e.g. to undertake a journey so that one cannot hear Mass : for this would be to wish to violate the law ;

2° indirectly, i.e. for another end, with the prevision however that the law cannot be fulfilled, it is illicit to place or not to remove proximate impediments, i.e. at the very time of the obligation or a little before when it morally and proximately already urges, e.g. to begin a journey on the evening before the day of precept ; unless however there is a proportionately grave cause, e.g. a grave inconvenience, or extraordinary means would have to be employed, e.g. to go to the church : for then the principle of the cause with a double effect, one good, the other evil, holds ;

3° to place or not to remove remote impediments is not prohibited, e.g. on Monday to begin a journey or to place the cause of sickness, because of which one cannot hear Mass on Sunday or fast on Friday : for it would be a great and grave inconvenience to oblige even to avoid remote impediments. These namely are not to be avoided as causes so that the precept may be fulfilled, or as remote and accidental causes, which, even if prohibited, are not precisely prohibited lest this effect follow.

380. Remark. — As from fault, so impotence in fulfilling the law avails also to excuse from penalty, or to diminish it (cf. can. 2199, 2203 § 2, 2205).