Ex turpi causa non oritur actio - "From a dishonorable cause an action does not arise." A party cannot bring a legal action for consequences of his own illegal act.⏎
In claris non fit interpretatio - When a rule is clearly intelligible, there is no need of proposing a (usually extensive) interpretation.⏎
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]⏎
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).⏎