Nulla poena sine lege

Nulla poena sine lege (Latin for "no penalty without law", Anglicized pronunciation: /ˈnʌlə ˈpnə ˈsn ˈl/ NUH-lə PEE-nə SY-nee LEE-jee) is a legal principle which states that one cannot be punished for doing something that is not prohibited by law. This principle is accepted and codified in modern democratic states as a basic requirement of the rule of law.[1] It has been described as "one of the most 'widely held value-judgement[s] in the entire history of human thought'".[2]