Arden Rowell.
Do people know the law? On the one hand, it is a brocard, sometimes traced to Aristotle, that nemo censetur legem ignorare: “nobody is thought to be ignorant of the law.” The same intuition underlies the classic maxim that ignorance of the law is no excuse. The intuition behind these principles has both doctrinal and theoretical heft: it underlies important common law doctrines, including those of excuse and mistake, and informs theoretical accounts of law that presume that law guides behavior.