According to A.A. Luce, "It is a legal phrase; for the elenchus in Greek law was the refutation on the charge; and ignoratio elenchi means ignorance of, or ignoring, the charge to be refuted. The counsel who does not 'know his brief' or who ignores it, cannot refute the charge, and is reduced to spending time and eloquence in proving what no one denies, in proving irrelevant, or in 'abusing the plaintiff's attorney'. Similarly the disputant who does not, or will not, understand the matter in dispute, and who avoids or confuses the issue, or proves what is beside the point, or passes off some irrelevance for proof, is guilty of ignoratio elenchi." (A.A. Luce: Logic, Teach Yourself, The English Universities Press Ltd, London, 1956).