Abstract
The common law doctrine of mistake of fact or civil law works as denial of offending, but dishonesty works as one of the definitional elements of crimes such as theft and fraud. It is argued in this article that the rulings in R v Barton [2020] 3 WLR 1333 and Ivey v Genting Casinos (UK) (trading as Crockfords Club) [2018] AC 391 do not change the doctrine of mistake of fact or civil law but do change the law in respect of mistakes about what is honest. A defendant whose conduct is taken as dishonest according to community standards may well avoid criminal liability if he was genuinely mistaken about a fact or civil law right. It is submitted that since the doctrine of mistake of fact or civil law is already provided for, the law is not expanded greatly by the rulings in Ivey and Barton which merely bring back the objective test of dishonesty that had long been established before the Ghosh test. The decision in Barton is substantively welcome, even though the change in the law arose from a civil law case where dishonesty was not an issue before the court.