OBROGATION. - O. (from *obrogare*, i.e., to contravene *rogare*) is a modification of an existing law effected by adding to it while detracting from another part.
The concept of O. is defined by Ulpian: *«Lex ... obrogatur id est mutatur aliquid e prima lege»* (D. 50, 16, 102); and this was the understanding among decretists. Later, more recent canonists such as Maroto, Chelodi, Vermeersch-Creusen, and civilists considered O. to be an implicit revocation of the law, achieved through a law contrary to the first, and distinguished it from abrogation, which is an explicit revocation.
The CIC refers to O. in three canons: in can. 3: *obrogant*; in can. 22: *obrogat*; in can. 2226: *obrogat*. However, not always with the same meaning: indeed, in can. 3 the verb has the meaning of a simple modification; in can. 2226 of abrogation; in can. 22 the term O. is used in a general sense to indicate both explicit and implicit abrogation.
O. must be clearly evident, as it ultimately constitutes a correction of the law and, as such, is odious. Therefore, in case of doubt, it is not presumed.
The cessation of a law that occurs through O., i.e., through the introduction of a contrary law, requires promulgation, without which a new obligation cannot be imposed.