Rules and theory of criminal law: the purposes of criminal law, the relationship between criminal law and morality and justice, fault, and the harm principle.

What this dot point is asking

AQA wants you to explain the purposes of the criminal law and the underlying theories, including fault, the harm principle, and how criminal law relates to morality and justice. This synoptic theme should be applied to the substantive offences and defences.

The purposes of criminal law

Fault

The level of fault affects both liability and sentence: intention is more blameworthy than recklessness, which is why murder (intention) is treated more seriously than constructive manslaughter. Strict liability offences, which need no proof of fault as to one element (Sweet v Parsley, R v G), are an exception justified by public protection.

The harm principle, morality and justice

The harm principle, set out by John Stuart Mill, holds that the law may restrict a person's freedom only to prevent harm to others, not merely to enforce morality or protect people from themselves. This was central to the Hart-Devlin debate, sparked by the Wolfenden Report (1957) on homosexuality and prostitution. Lord Devlin argued that society is held together by a shared morality and that the law is entitled to enforce that morality to prevent social disintegration, just as it suppresses treason. Professor Hart, drawing on Mill, replied that using the criminal law to enforce private morality is unjustified paternalism unless the conduct harms others, and that tolerance of difference is itself a public good.

The substantive law illustrates the unresolved tension. In R v Brown the House of Lords criminalised consensual sadomasochistic harm on public-policy and morality grounds, yet in R v Wilson a husband who branded his wife at her request was acquitted, a distinction many find hard to justify on the harm principle alone. The decriminalisation of suicide (Suicide Act 1961) and of consensual adult homosexual acts reflects the harm-principle view, while the continued criminalisation of drug possession reflects Devlin's. Criminal law aims at justice, but the legally correct result is not always the morally satisfying one: jury equity, as in R v Ponting (acquittal despite a clear breach of the Official Secrets Act), shows juries occasionally substituting their own sense of justice for the strict letter of the law.

How the theory theme is examined

The rules-and-theory content underpins the longer evaluative essays in the criminal module. Examiners reward candidates who treat it synoptically, linking abstract concepts such as fault and the harm principle to concrete offences and defences, and who build a clear argument supported by named theorists and cases rather than describing the theories in isolation.