How does one prove the law? If your neighbor breaks your window, the law regulates how you can show your claim to be true or false; but how do you prove that in breaking your window your neighbor has broken the law? American jurisprudence devotes an elaborate body of doctrine-and an equally elaborate body of accompanying scholarly commentary-to worrying about how to prove facts. It establishes rules for the admissibility of evidence, creates varying standards of proof, and assigns burdens of proof that determine who wins or loses when the facts are unclear. But the law is shockingly inexplicit when addressing these issues with respect to the proof of legal claims. Indeed, the entire language of evidentiary proof, so sophisticated when it comes to questions of fact, is largely absent from the American legal system with respect to questions of law.