Abstract

The slogan that criminal liability requires an ‘act’, or a ‘voluntary act’, is still something of a commonplace in textbooks of criminal law. There are, it is usually added, certain exceptions to this requirement— cases in which liability is in fact, and perhaps even properly, imposed in the absence of such an act: but the ‘act requirement’ is taken to represent a normally minimal necessary condition of criminal liability. Even offences of strict liability, for which no mens rea is required, require an act: thus to the familiar slogan that actus non facit reum nisi metis sit rea we can add the prior, more fundamental slogan that mens non facit reum nisi actus sit reus ; before we ask whether a defendant acted with mens rea or fault, we must ask whether he committed a criminal act at all