Haughton v. Smith

Haughton v. Smith, [1973] 3 All ER 1109, [1974] 3 W.L.R. 1 is the House of Lords case dealing with attempted crimes in relation to actus reus. Lord Dilhorne's statment about the impossibility of crimes is often quoted at 19 (citing to All E.R..):

A man taking his own umbrella from a club, thinking it the property of someone else, does not steal. His belief does not convert his conduct into an offence. In my view, it matters not that the crime cannot be committed as a result of physical impossibility, e.g. the absence of the property he wants to steal, or of legal impossibility. In either case he cannot be convicted of an attempt when he could not be convicted of the full offence if he had succeeded in doing all that he attempted to do. Conduct which is not criminal is not converted into criminal conduct by the accused believing that a state of affairs exists which does not.

This case was subsequently overturned by statute. There is an in-depth discussion of the law of attempted crimes, in particular the debate about criminal liability in issues of impossible crimes.