OBROGATION. - O. (ob-rogare, that is, contra rogare) is a modification of an already existing law, effected in such a way that, with one part added, another is removed.
The concept of o. is defined by Ulpian: «Lex ... obrogatur id est mutatur aliquid e prima lege» (D. 50, 16, 102); and this was likewise its meaning in the decrees. Subsequently, more recent canonists, such as Maroto, Chelodi, Vermeersch-Creusen, and civil jurists regarded o. as an implicit revocation of the law, effected, that is, by means of a law contrary to the former one, and distinguished from abrogation, which is an explicit revocation.
In the CIC o. is mentioned in three canons: in can. 3: obrogant; in can. 22: obrogat; in can. 2226: obroget. It does not, however, always have the same meaning: in can. 3 the verb signifies a simple modification; in can. 2226, abrogation; in can. 22 the term o. is used in a general sense, to indicate explicit and implicit abrogation.
O. must be clearly established, since it is, ultimately, a correction of the law and, as such, odious. It is therefore not presumed in cases of doubt.
The cessation of a law effected by o., that is, by the introduction of a contrary law, requires promulgation, without which a new obligation cannot be imposed.