Abrogation

The destruction or annulling of a former law, by an act of the legislative power, or by usage. A law may be abrogated or only derogated from; it is abrogated when it is totally annulled; it is derogated from when only a part is abrogated: derogatur legi, cum pars detrahitur; abrogatur legi, cum prorsus tollitur. Lex rogatur dum fertur; abrogatur dum tollitur; derogatur eidem dum quoddam ejus caput aboletuer; subrogatur dum aliquid ei adjicitur; abrogatur denique, quoties aliquid in ea mutatur.

Abrogation is express or implied; it is express when it, is literally pronounced by the new law, either in general terms, as when a final clause abrogates or repeals all laws contrary to the provisions of the new one, or in particular terms, as when it abrogates certain preceding laws which are named.

Abrogation is implied when the new law contains provisions which are positively contrary to the former laws, without expressly abrogating such laws. It is also implied when the order of things for which the law had been made no longer exists, and hence the motives which had caused its enactment have ceased to operate.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.