Principles derived from Roman law, which held that some legal principles were "natural" or self-evident and did not require a statutory basis. A word used to refer to situations where the two basic legal safeguards of "audi alteram partem" (the right to be heard) and "nemo judex in parte sua" (no person may judge their own case) apply. These rules govern all decisions by judges or government officials when they take quasi-judicial or judicial decisions.