Ignorantia juris non excusat - "Ignorance of the law is no excuse." Not knowing that one's actions are forbidden by the law is not a defense.⏎
Inadimplenti non est adimplendum - "One has no need to respect his obligation if the counter-party has not respected his own." This is used in civil law to briefly indicate a principle (adopted in some systems) referred to as the synallagmatic contract.[3]⏎
Fiat justitia et pereat mundus - "Let there be justice, though the world perish." Often used as a motto, notably by Ferdinand I, Holy Roman Emperor.⏎