§ I. On the nature of those things which release from obligation

137. • Causes releasing from obligation are either exempting or impeding. The former are those which totally withdraw someone from the dominion of law, for example, if someone withdraws himself outside the place which the law affects. The latter are those which impede, or excuse, a subject remaining under the law from its fulfillment. But these impeding causes are reduced to ignorance and impotence.

Principles. - I. Exempting causes totally free one from the obligation of law; for no one can impose a precept upon a man not subject to himself. Moreover, where some exempting cause is present, he who was subject to the law ceases to be subject to the same law either by reason of the territory from which he is absent, or by reason of privilege. Therefore.

II. Invincible ignorance excuses from law in this sense alone, that its violation is not imputed unto formal fault, as is plain. - But vincible ignorance does not excuse from any fault, since it could, or can, be laid aside by serious diligence.¹

III. Physical impotence always excuses from observing law, as the very common axiom has it: "No one is held to the impossible." Moral impotence likewise excuses; because the legislator is not judged to urge obligation with an inconvenience which can be considered grave (n. 125. V.). Impotence exempts those not observing the law even from material fault.

Hence grave fear, excluding damage to society or religion, excuses from human law; because human law does not oblige with grave harm. It also sometimes excuses, although with greater difficulty, from a positive divine precept, for example, from the integrity of Confession; indeed even from an affirmative natural precept, for example, of keeping a deposit with danger of life, of which, however, there is then rather no case; for you did not will to oblige yourself to keep the deposit even with danger of life. Yet it never excuses from a negative natural precept, because the object of this is intrinsically evil. Nor should you say that it is licit to steal in extreme necessity; for then it ceases to be theft.¹

I said: grave fear excuses from human law, excluding damage to society or religion; for this rather than private damage must be avoided; moreover, in each of these cases there enters the natural precept of guarding against damage to society and religion. Thus a soldier keeping watch ought rather to die than, when the enemy is approaching, to be silent (n. 105. 2°). Hence also, if you are directly compelled in contempt or in injury of ecclesiastical power to communicate with one to be avoided, to work on a feast day, to eat forbidden foods on a fast day, you must refuse even with grave damage to yourself, unless by protesting you can avert the contempt. Thus, if an unbelieving or heretical father of a family should say to his Catholic children: "I will that you eat meats on Friday, and that in contempt of the Pope and the Church," the children would not sin if they replied: "Father, know that we eat meats because you refuse to set other foods before us; for in this case it is licit for us to eat them."

138. • Quaer. Is he who is impotent for the whole held to a part?

Resp. Affirmatively, when the matter of the law is divisible, and the end of the precept remains in the individual parts. It is established moreover from proposition 54 condemned by Innocent XI (p. xvii). Therefore it is otherwise if that part is so slight that it conduces in no way to the end of the precept, - or if it is uncertain whether there is power even as to that part of the precept, as, for example, in the sick as to the Breviary, and in the weak and in convalescents as to fasting; for scarcely, or not even scarcely, can it be determined what they can do and how far. Hence, lest they undergo danger of anxiety or notable detriment to health, the benign Mother Church is not to be supposed to will to oblige them even to a part.¹

Hence 1° He who cannot fast in Lent ought to abstain from meats, if he can. Likewise he who cannot fast on all days is held on the days on which he can without grave inconvenience.

2° If someone lacking a Breviary knows a few things from the Hours by memory, he is not held to recite them; otherwise if he holds in memory a notable part, for example, Vespers or Compline.

3° He who vowed a pious pilgrimage, and cannot complete the whole journey, is not held to begin it, because the end of the precept cannot be obtained.²