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 ruat caelum - "Let justice be done though the heavens fall." Also sometimes a motto, a legal maxim that justice must be done regardless of the result otherwise.⏎
Iura novit curia - The judge knows the law (technically, there is no need to "explain the law" or the legal system to a judge/justice in any given petition).⏎