— Also termed ignorantia juris neminem excusat (ignorance of the law excuses no one); ignorantia legis non excusat; ignorantia juris haud excusat. [Cases: Criminal Law 32. C.J.S. Criminal Law §§ 56, 94.]
“Almost the only knowledge of law possessed by many people is that ignorance of it is no excuse (ignorantia juris non excusat). This maxim was originally formulated at a time when the list of crimes, broadly speaking, represented current morality (mala in se), but we now have many other crimes that are the result of administrative or social regulation (mala prohibita), which are equally governed by the maxim. The rule is, then, that whereas ignorance of fact can excuse, to the extent that it negatives mens rea or fault, ignorance of the law generally does not.” Glanville Williams, Textbook of Criminal Law 405 (1978).
