We must resist principles.
Principis beneficium debet esse mansurum.
The favour of a prince ought to be permanent.
Privatorum conventio juri publico non derogat.
The agreement of a private person, does not derogate from public law.
Privatum commodum publico cedit.
Private advantage yields to public.
Privilegium non valet contra rempublicam.
Privilege is not valid against the state.
Pro possessore habetur, qui dolo desiit possidere.