Question Ninth. On the Cessation of Law.

The law itself can cease in three ways: a. through abrogation or derogation; b. through cessation of the end; c. through contrary custom.

198. On abrogation. 1. Abrogation is the total removal of a law made by the legislator himself; derogation is the partial removal of a law.

2. No one can altogether abrogate a law or derogate from it in part except the legislator himself, or his successor, or his superior: for just as the existence of the law depends upon the will of the legislator, so also its cessation.

3. A law can be abrogated either by declaring that some law already lacks the force of obliging, or by issuing a new law which is entirely contrary to a preexisting law.

199. On the cessation of the end. 1. Declarations. a. The end or motive cause of a law can cease adequately if the whole reason which moved the legislator to issue the law ceases, or inadequately if only one reason ceases while another remains.

b. The adequate end of a law can cease universally or for the greater part of the community, or particularly, or for an individual person only.

c. The end of a law is said to cease contrarily when its observance is harmful or too difficult or altogether useless; and it is said to cease negatively if the end of the law does not exist in a particular case, but nevertheless the observance of the law is neither harmful nor impossible nor altogether useless (for the community).

If, e.g., the prohibition of reading a bad book cannot be observed without detriment to faith, because faith cannot be defended unless the book is read, the end of the law ceases contrarily; it ceases negatively if the reading brings no damage only to the reader.

2. Principles. a. When the motive cause ceases adequately and universally, the law itself ceases: for if the end of the law ceases, the law becomes useless and therefore null; when the motive cause ceases inadequately, the law does not cease, because the law is not yet useless.

b. If the end of the law ceases contrarily in a particular case, the law ceases; but if the end of the law ceases only negatively, the law does not cease.

The reason is: if the end of the law ceases contrarily, in reality we can use epikeia; but if the end of the law ceases only negatively, the common good requires that a law which has been issued for the common good be observed by all: for unless it must be observed by all, it soon loses efficacy, because many, thinking that the end of the law has ceased for them, would not observe the law and by their example would seduce many others. Besides, if it is permitted to the judgment of individuals whether in a particular case the danger of damage ceases, laws of this kind would be useless for most people on account of the danger of hallucination.

The opinion which holds that a law ceases when its end ceases merely negatively, and which some authors (Tamburini) hold as probable, is not brought into practice, because it seems to lack probability. Thus the proclamation of marriage is never omitted, even if there is no danger of an invalid marriage; likewise the reading of a prohibited book is not permitted where no danger of perversion is feared for the particular person.¹ The reason of that opinion is this. Just as a law ceases universally if the end of the law ceases for the whole community, because the law has become useless, so the law ought to cease particularly where the end of the law ceases for a particular person, because the observance of the law is useless for this person. But this reason lacks probability, because the observance of a law which is useless for a particular person is useful, indeed even necessary, for the community; therefore the legislator is judged to urge the law whose end ceases only negatively.

¹ Cf. St. Alphonsus n. 199.