Nemo debet esse iudex in propria - "No one shall be a judge in his own case." In the past it was thought that it included just two rules namely (1) nemo debet esse judex in propria causa (no one shall be a judge in his own case).⏎
Lex posterior derogat priori - "Later law removes the earlier." More recent law overrules older ones on the same matter.⏎
Lex specialis derogat legi generali - "A law governing a specific subject matter overrides a law which only governs general matters."⏎
Nemo judex in sua causa - "No one shall be a judge in his own case." Prevents conflict of interest in courts. Often invoked when there is really no conflict, but when there is even the appearance of one.⏎