Introduction
The relationship between law and morality is one of the most enduring debates in legal philosophy. At its core lies a fundamental question: what is the proper function of law in a society? Should the law act as a moral guardian, enforcing a shared set of values to maintain social cohesion, or should its role be limited to maintaining order and preventing harm, leaving questions of personal morality to the individual? The proposition that law enforcing morality is an inherent ‘good’ suggests a preference for the former. This essay will critically discuss this notion by examining the main arguments for and against the legal enforcement of morality. It will draw on the classic debate between Lord Devlin and H.L.A. Hart, as well as key legal cases, to explore this tension. This essay will argue that while the law inevitably reflects certain core moral principles, the idea that it should be used as a general tool for enforcing a specific moral code is problematic. A pluralistic and free society should be cautious of using the coercive power of the law to regulate private moral choices, favouring an approach based on preventing harm rather than enforcing virtue.
The Argument for Legal Moralism
The view that law should enforce morality has deep roots in natural law theory, which posits that a necessary connection exists between law and morality. From this perspective, an ‘unjust law is no law at all’ (lex injusta non est lex), meaning that the validity of law is derived from its conformity with a higher moral order. While this is a broad tradition, the most prominent modern defence of legal moralism in English law came from the judge Lord Devlin. In response to the Wolfenden Report (1957), which recommended decriminalising homosexual acts between consenting adults in private, Devlin argued that society has a right to enforce its shared morality through law.
Devlin’s central thesis was that a shared public morality is the ‘cement of society’; without it, society would disintegrate (Devlin, 1965). He argued that just as the law protects a society from treason and sedition, it also has the right to protect itself from moral subversion from within. For Devlin, the standard for legal intervention was not whether an act caused harm to a specific individual, but whether it was regarded with ‘intolerance, indignation and disgust’ by the ordinary person (Devlin, 1965, p. 17). If a particular practice was viewed as grossly offensive to a society’s common morality, then the law could justifiably prohibit it, even if it occurred in private and between consenting adults.
The courts have, at times, adopted a similar stance. A key example is the case of Shaw v Director of Public Prosecutions [1962] AC 220. The defendant had published a ‘Ladies Directory’ which listed the contact details of prostitutes. As there was no specific offence covering this, he was convicted of the novel crime of ‘conspiracy to corrupt public morals’. In his judgment, Viscount Simonds declared that the courts have a “residual power… to conserve not only the safety and order but also the moral welfare of the State”. This decision exemplifies the Devlinite position: the court created a new offence to punish behaviour it deemed morally harmful to society, even in the absence of a clear victim in the traditional sense. Proponents of this view would argue this is a clear example of law acting as a force for good by upholding public decency and morality.
The Argument Against Legal Moralism
The opposing view, most associated with legal positivists, challenges the necessary link between law and morality. As the positivist John Austin argued, “The existence of law is one thing; its merit or demerit is another” (Austin, 1995, p. 157). This separation thesis suggests that law is valid because it has been created by a recognised authority, not because it is morally good. This provides the theoretical foundation for arguing that the law should not be a vehicle for moral crusades.
The classic liberal argument against legal moralism was articulated by John Stuart Mill in his 'harm principle'. Mill (1859) contended that "the only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others." An individual’s own moral or physical good is not a sufficient reason for the state to interfere with their liberty. Building on Mill’s work, the legal philosopher H.L.A. Hart mounted a powerful critique of Lord Devlin’s position. Hart (1963) questioned the very basis of Devlin’s argument, asking for evidence that a failure to enforce a shared morality would lead to social disintegration. He argued that Devlin confused the idea of a society's morality changing with the idea of that society collapsing.
Furthermore, Hart raised a crucial question for pluralistic societies: whose morality is the law to enforce? In a society with diverse beliefs, enforcing the majority’s moral view can lead to the oppression of minorities and the stifling of individual freedom. Hart advocated for a more limited role for the law, one which respects a private sphere where individuals can make their own moral choices without legal interference, provided they do not harm others.
This tension was starkly illustrated in R v Brown [1994] 1 AC 212, where a group of men were convicted for engaging in consensual sado-masochistic acts in private. The majority in the House of Lords refused to accept consent as a defence, with Lord Templeman stating it was not in the public interest for people to cause each other bodily harm for sexual gratification, describing it as a “cult of violence”. This was essentially a moral judgment, reflecting the court’s disgust at the men’s activities. However, the dissenting judgment of Lord Mustill powerfully echoed the arguments of Hart and Mill. He argued that these were private matters of sexual morality and that the criminal law should not "enter the bedrooms of private citizens" to enforce a particular code of conduct. The decision in Brown shows the danger highlighted by Hart: the use of law to punish behaviour that offends a judge’s sense of morality, rather than to prevent demonstrable harm to society.
Conclusion
The notion that law enforcing morality is a good that we should all aim for is an attractive but ultimately flawed proposition. It is clear that law and morality are not entirely separate; laws against murder, theft, and fraud are underpinned by a near-universal moral consensus. In this sense, the law does and should enforce fundamental morality to enable basic social cohabitation. However, the debate becomes contentious when considering matters of private morality, particularly in areas like sexuality and personal lifestyle choices.
Lord Devlin’s argument that society has a right to protect its shared morality has a certain appeal, but it rests on the unproven assumption that moral diversity leads to social collapse. As H.L.A. Hart argued, this approach risks creating an unnecessarily punitive and intolerant society that oppresses minorities and personal liberty. The harm principle articulated by Mill provides a more stable and defensible boundary for legal intervention in a modern, pluralistic society. Cases like Shaw v DPP and R v Brown demonstrate that when courts take on the role of moral guardians, they risk creating uncertainty and infringing on individual autonomy in ways that are difficult to justify.
Therefore, while the law cannot be entirely value-neutral, it is not a ‘good’ to aim for the law to become a comprehensive enforcer of a particular moral code. A better aim is for the law to provide a framework that protects individuals from harm, while allowing for the maximum degree of freedom for people to pursue their own conceptions of a good life. The law should protect citizens from each other, not from themselves.
References
Austin, J. (1995) The Province of Jurisprudence Determined. Cambridge University Press (originally published in 1832).
Committee on Homosexual Offences and Prostitution (1957) Report of the Committee on Homosexual Offences and Prostitution (Wolfenden Report), Cmnd. 247. HMSO.
Devlin, P. (1965) The Enforcement of Morals. Oxford University Press.
Hart, H.L.A. (1963) Law, Liberty and Morality. Stanford University Press.
Mill, J.S. (1859) On Liberty. John W. Parker and Son.
R v Brown [1994] 1 AC 212.
Shaw v Director of Public Prosecutions [1962] AC 220.
