Chapter VIII. On the Cessation of Law

121. • Law can cease in various ways.

1. Through abrogation, or derogation, according as it is abolished altogether or only in part: for just as a Superior can make a law, so he can remove or restrict the same law.

2. Through cessation of the adequate motive cause, or the total end, on account of which it was made with respect to the whole community; for when the cause of the law ceases, the legislator cannot reasonably urge it.

3. Through desuetude, or through a contrary custom clothed with the due conditions; for then at least the legal consent of the Superior accedes. - Thus most commonly.

QUESTION 1. Whether a law ceases when the final cause ceases only in a particular case, that is, with respect to some persons?

I answer. No, unless it cannot be observed without grave inconvenience; the reason is that the adequate end of the law regards those things which happen commonly, not however particular cases; therefore these do not prevent the end of the law, and therefore the law itself, from persevering. Hence spouses are not exempted from the proclamation of banns, even if they know with certainty that no impediment underlies the marriage. - Suarez, Laymann, and St. Lig., no. 199.

QUESTION 2. Whether someone can read prohibited books, if he fears no danger to himself from them?

I answer: No, for the reason just given; add besides the danger of error. - Thus commonly. - St. Lig., no. 199. - See Cases, no. 109 and following.