(L. abrogare); to repeal or annul a law; rogare literally means “to ask,” to propose a law. Total revocation of a law or an earlier law made directly and expressly or implicitly by the one who has legislative power or by later law. Abrogation, which is the total annulling of a law, is to be distinguished from the term derogation, which is used where a law is only partially abrogated. Abrogation may be either express or implied. It is express either when the new law pronounces the annulment in general terms, as when in a concluding section it announces that all laws contrary to the provisions of the new one are repealed, or when in particular terms it announces specifically the preceding laws which it repeals. It is implied when the new law contains provisions that are positively contrary to the former laws without expressly abrogating those laws, or when the condition of things for which the law had provided has changed and consequently the need for the law no longer exists. The abrogation of any statute revives the provisions of the common law that had been abrogated by that statute (see “abrogate”).
Abrogation of law takes place due to a number of reasons such that the philosophy or theology which informs the law has been changed (e.g. abolition of capital punishment), change in circumstances for which the law was made (e.g. abolition of laws pertaining to slavery) etc.