Article — Merkelbach, Summa Theologiae Moralis
Article VI: On Abrogation and Derogation
St. Thomas, I-II, q. 97, a. 2.
401. Abrogation (abroger, revoquer, rapporter) is the abolition or revocation of the whole law; derogation (deroger, modifier) is the abolition or revocation of part of the law, the other part retaining vigor. They differ from invalidation of law: the latter is the abolition, by a superior, of a law enacted by an inferior so that it never obtains force; but the former revoke a law which has had force.
They can be made directly or expressly (formal cessation), or tacitly and indirectly (virtual cessation), by enacting an incompatible law (obrogation).
402. Those who can make laws can abrogate and derogate, namely, the legislator himself, his successor, and his superior. For "every thing is dissolved by the same causes by which it arises."
As regards ecclesiastical laws, these are: the Pontiff for all; Councils for the laws of their own jurisdiction; bishops for diocesan laws, even those enacted in synod, but not for laws enacted in a provincial council, or for diocesan laws if they have been confirmed by the Supreme Pontiff in specific form, that is, not simply in favor of the superior, but in favor of the community, so that the pontiff has made them his own.
They validly do this even without a reason, because positive law essentially depends on the will of the legislator; they do not licitly do it without a just cause, because to abrogate useful laws or frequently change them into others brings detriment to the common good: for thus the people are brought into contempt, and laws are less esteemed and observed, since custom avails much for observance of law.
403. Observations. - 1. Canon 22 is to be noted: "A later law, enacted by competent authority, obrogates a prior law if it expressly says so, or is directly contrary to it, or orders anew the whole matter of the prior law; but a general law in no way derogates from the statutes of special places and singular persons, unless something else is expressly provided in it." Nevertheless, from the express determination of the law, "any laws whatever, whether universal or even particular, opposed to the prescriptions of the Code, are abrogated, unless concerning particular laws the contrary is expressly established" (can. 6, 1°).
- Concerning tacit abrogation, note: a) a later law is to be reconciled with an earlier one insofar as the propriety of the words permits (can. 23), for change of law is of itself harmful to the community and is to be interpreted strictly;
b) by a general law a prior general law is abrogated insofar as it is directly contrary; not particular customs or the statutes of special places or singular persons, which can be unknown to the legislator;