Non faciat malum, ut inde veniat bonum - "Not to do evil that good may come." Performing some illegal action is not excused by the fact that a positive result came therefrom. Often used to argue that some forms of expression, such as graffiti or pornographic films, cannot be given the protection of law (e.g. copyright) as they are or may be considered illegal or morally reprehensible.⏎
Par in parem non habet imperium - Equals have no sovereignty over each other.⏎
Nullum crimen, nulla poena sine praevia lege poenali - There can be neither crime nor punishment unless there is a penal law first.⏎
Prior tempore potior iure - "Earlier in time, stronger in law". A legal principle that older laws take precedence over newer ones. Another name for this principle is lex posterior.⏎