Iura novit curia, commonly translated as “the judge knows the law”, is a fundamental principle of legal procedure. An early reference to this maxim appears already in Aristotle’s Rhetoric. Reflecting upon the multiple uses of rhetoric, Aristotle argued:
It is not right to pervert the judge by moving him to anger or envy or pity - one might as well warp a carpenter’s rule before using it. Again, a litigant has clearly nothing to do but to show that the alleged fact is so or is not so, that it has or has not happened. As to whether a thing is important or unimportant, just or unjust, the judge must surely refuse to take his instructions from the litigants: he must decide for himself all such points as the law-giver has not already defined for him.
Aristotle hence advocated a system in which the role of the parties was limited to adducing the relevant facts, while it was incumbent upon the judge to make his own legal assessment. A similar allocation of responsibilities between parties and judges emerged as a legal principle in Roman law. The Latin dictum “da mihi factum, dabo tibi ius” – give me the facts, I will give you the law – reflected this.
Over time, the principle iura novit curia spread among various civil law jurisdictions. This development gained momentum with the increase of legally trained decision-makers across continental Europe.