Course-focused and comprehensive, the Textbook on series provides an accessible overview of the key areas on the law curriculum. This chapter discusses the meaning of negligence, arguments for and against negligence as a basis for criminal liability, the meaning of strict liability, the origins of strict liability, justifications for strict liability, identifying offences of strict liability, the presumption of mens rea in offences of strict liability, defences to strict liability, and strict liability and the European Convention on Human Rights. A Law in Context feature examines critically the use of strict liability as the basis for liability in the offence of paying for the sexual services of a person who has been subject to exploitation.