Should Law Improve Morality?


Lawyers and philosophers have long debated whether law should enforce social morality. This paper explores whether law should improve social morality. It explains how this might be possible, and what sort of obstacles, factual and moral, there are to doing so. It concludes with an example: our law should attempt to improve our social morality of sexual conduct.

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  1. 1.

    J.S. Mill, On Liberty (London: Penguin, 2010 [f.p. 1859]); James Fitzjames Stephen, Liberty, Equality and Fraternity R.J. White, ed (Cambridge: Cambridge University Press, 1967 [f.p. 1873]; H. L. A. Hart, Law, Liberty and Morality (Oxford: Oxford University Press, 1968 [f.p. 1964]); Patrick Devlin, The Enforcement of Morals (Oxford: Oxford University Press, 1968 [f.p. 1965]; Ronald Dworkin, Taking Rights Seriously (Harvard: Harvard University Press, 1978), ch 10; Joseph Raz, The Morality of Freedom (Oxford: Oxford University Press, 1986) ch 14–15.

  2. 2.

    The Supreme Court of Canada made famous errors along these lines: see Leslie Green, ‘Men in the Place of Women, from Butler to Little Sisters,’ (2006) 44 Osgoode Hall Law Journal 1.

  3. 3.

    The results of deliberate intervention are also subject to less deliberate forms of law-creation, so the process is iterative.

  4. 4.

    Hart, Law, Liberty, and Morality 17–24.

  5. 5.

    Hart, Law, Liberty and Morality 24.

  6. 6.

    Devlin, The Enforcement of Morals 90–93.

  7. 7.

    H. L. A. Hart, The Concept of Law, 3rd ed, L. Green intro; P.A. Bulloch and J. Raz eds (Oxford: Oxford University Press, 2013), 175–178.

  8. 8.

    Ibid 175.

  9. 9.

    Ibid 173–180.

  10. 10.

    G. J. Warnock, The Object of Morality (London: Methuen, 1971).

  11. 11.

    And that would make for a fifth contrast between law and morality. The law does not necessarily present itself as correct, pace Robert Alexy. (See Robert Alexy, The Argument from Injustice: A Reply to Legal Positivism, R Paulson and S Paulson, trans (Oxford: Oxford University Press, 2002.) The law presents itself as morally binding whether or not it is correct. For discussion, see John Gardner, ‘How Law Claims, What Law Claims,’ in his Law as a Leap of Faith (Oxford: Oxford University Press, 2012), ch 5, esp 139–145.

  12. 12.

    Hart, Law, Liberty and Morality 22.

  13. 13.

    Hart, The Concept of Law, 255.

  14. 14.

    Hart, The Concept of Law, 56.

  15. 15.

    At Ibid 61 Hart suggests that acceptance can be shown in one’s acquiescence in a standard, but that is not consistent with ‘using’ it as a guide to conduct. This is probably a slip—at 117 the obedience of the masses is contrasted with acceptance, not offered as an example of acceptance.

  16. 16.

    E.g. Hart, The Concept of Law, 102. On this sort of condition see David Lewis, Convention (Cambridge MA: Harvard University Press, 1969). I put ‘common knowledge’ in scare quotes: it suffices for there to be nested mutual beliefs. They need not all be true, and thus what is common need not be knowledge.

  17. 17.

    See Hart, The Concept of Law, 114–117. On the moral significance of this feature of law see Leslie Green ‘Positivism and the Inseparability of Law and Morals,’ (2008) 83 New York University Law Review (2008) 1035, 1054–1058.

  18. 18.

    For evidence of a large gap between social morality and criminal law in the US, see Paul H. Robinson and John Darley, Justice, Liability, and Blame: Community Views and the Criminal Law (Boulder CO: Westview Press, 1995).

  19. 19.

    Albert Venn Dicey, Lectures on the Relation between Law and Public Opinion in England during the Nineteenth Century, Richard VandeWetering ed (Indianapolis: Liberty Fund, 2008). [f.p. 1905].

  20. 20.

    The raw data are available online at

  21. 21.

    Devlin, The Enforcement of Morals, 14–15.

  22. 22.

    This is the ‘necessary content’ or ‘minimum content’ thesis in general jurisprudence. I offer a defence of it in ‘The Morality in Law,’ in A. Dolcetti, L. Duarte d’Almeida and J. R. Edwards, eds, Reading HLA Hart’s ‘The Concept of Law’ (Oxford: Hart Publishing, 2013), forthcoming.

  23. 23.

    It may be necessary that it aim or attempt to regulate these things well, but it can attempt and fail. See Green, ‘The Morality in Law.’

  24. 24.

    Hart, The Concept of Law, 175.

  25. 25.

    In an inversion of Hart’s argument, Neil MacCormick concludes that there must be informal rules of moral change, since there are rules of social morality and they plainly change. He seems driven to this conclusion by an artificially narrow idea of what social rules are (they must be crisp, clear, have canonical formulations, and so on) together with the implicit supposition that it would take a rule of change to change rules like that. Neither view is correct. See Neil MacCormick, H.L.A. Hart, 2nd edn (Stanford CA: Stanford University Press, 2008), 67–71.

  26. 26.

    Hart, The Concept of Law, 176.

  27. 27.

    Ibid, 177.

  28. 28.

    ‘Artificial’ is not a term of criticism; I use it in the economic sense. Copyright gives people monopolistic rights that do not arise by mechanisms of ‘natural monopoly’ such as barriers to entry or increasing returns to scale. Whether or not ‘information wants to be free’, continuing legal intervention seems to be needed to sustain these monopolies.

  29. 29.

    For the logo and mission of the Center, go to

  30. 30.

    Human Rights Watch, This Alien Legacy: The Origins of “Sodomy” Laws in British Colonialism (New York: Human Rights Watch, 2008), 5.

  31. 31.

    Paul H. Robinson & Robert Kurzban, ‘Concordance and Conflict in Intuitions of Justice’ (2007) 91 Minnesota Law Review 1829; Paul H. Robinson and John M. Darley, ‘Intuitions of Justice: Implications for Criminal Law and Justice Policy,’ (2007) 81 Southern California Law Review 1.

  32. 32.

    Devlin, The Enforcement of Morals, 87.

  33. 33.

    Paul H. Robinson and Robert Kurzban, ‘Concordance and Conflict in Intuitions of Justice’. And see further evidence of cross-cultural variation in Donald Braman, Dan M. Kahan, and David A. Hoffman, ‘Some Realism about Punishment Naturalism,’ (2010) 77 Chicago Law Review 1532.

  34. 34.

    And also drunk driving, alcohol, and drugs offences: Paul H. Robinson and Robert Kurzban, ‘Concordance and Conflict in Intuitions of Justice’.

  35. 35.

    Teenage boys are notorious for bullying gay youth, but this does not show they think homosexuality immoral. A more likely explanation is that they find it threatening to their emerging psycho-sexual identities. See Carissa M. Froyum, “‘At Least I’m Not Gay’: Heterosexual Identity Making among Poor Black Teens,” (2007) 10 Sexualities 603; and, more optimistically, Mark McCormack and Eric Anderson, “‘It’s Just Not Acceptable Any More’: The Erosion of Homophobia and the Softening of Masculinity at an English Sixth Form,” (2010) 44 Sociology 843.

  36. 36.

    On the loss of salience see Leslie Green ‘Sexuality, Authenticity, and Modernity,’ (1995) 8 Canadian Journal of Law and Jurisprudence 67. This shows, by the way, why disagreement about the law of abortion is radically different: neither those who favour a permissive regime nor those who favour a restrictive one regard control over pregnancy and child-bearing as ‘not a moral issue’.

  37. 37.

    Robinson and Darley, ‘Intuitions of Justice,’ 28. See also the seminal study by Nigel Walker and Michael Argyle, ‘Does the Law Affect Moral Judgments?’ (1963) 4 British Journal of Criminology 570; and, more recently, Eric A. Posner, Law and Social Norms (Cambridge MA: Harvard University Press, 2002), and the sources cited therein.

  38. 38.

    Gerald N. Rosenberg, The Hollow Hope: Can Courts Bring About Social Change? 2nd edn (Chicago: University of Chicago Press, 2008).

  39. 39.

    By ‘conservative’ I mean morality-conserving, not ‘right-wing’. As Karl Marx saw, many right-wing views are morally revolutionary. The first chapter of the Communist Manifesto memorably proclaims that as the bourgeoisie revolutionize production, ‘All fixed, fast-frozen relations, with their train of ancient and venerable prejudices and opinions, are swept away, all new-formed ones become antiquated before they can ossify. All that is solid melts into air, all that is holy is profaned, and man is at last compelled to face with sober senses his real conditions of life, and his relations with his kind.’

  40. 40.

    For moderate utilitarian, or at any rate consequentialist, views of this sort see Richard B. Brandt, A Theory of the Good and the Right (Oxford: Oxford University Press, 1979), 110–129; and Robert E. Goodin, Utilitarianism as a Public Philosophy (Cambridge: Cambridge University Press, 1995), 132–148.

  41. 41.

    Devlin, The Enforcement of Morals, 93.

  42. 42.

    Ibid. Here, ‘law-makers’ include judges who apply general rules to particular cases, and who settled doubtful points by the exercise of their discretion.

  43. 43.

    Robinson and Darley, ‘Intuitions of Justice.’

  44. 44.

    Ibid 28.

  45. 45.

    Ibid 43.

  46. 46.

    Understood here as fully adequate, not as barely adequate.

  47. 47.

    It is difficult to articulate, let alone defend, the view that I am hinting at here, and also in Leslie Green, ‘Law as a Means,’ in Peter Cane, ed. Hart-Fuller: 50 Years On (Oxford: Hart Publishing, 2009), 169–188. For an incomplete and speculative general argument for the sort of the conclusion I have in mind see G. A. Cohen, Finding Oneself in the Other, M. Otsuka, ed (Princeton NJ: Princeton University Press, 2012), ch 8.

  48. 48.

    I say a little more about a performative understanding of consent in Leslie Green, The Authority of the State (Oxford: Oxford University Press, 1990), ch 6. I caution the reader that not all features of, or justifications for, consent to political authority carry over to consent to sex. For another performative account, with which I agree in part, see Alan Wertheimer, Consent to Sexual Relations (Cambridge: Cambridge University Press, 2003).

  49. 49.

    And I do mean agreeing, not forming an agreement in the sense of striking a bargain. What I have in mind is recognized in English law: ‘a person consents if he agrees by choice, and has the freedom and capacity to make that choice.’ Sexual Offences Act 2003 (UK) s 74.

  50. 50.

    But this does not mean that consent must be ‘expressed through behaviour’ or that consent cannot be given in secret, as Douglas Husak seems to assume, in ‘The Complete Guide to Consent to Sex: Alan Wertheimer’s Consent to Sexual Relations’ (2006) 25 Law and Philosophy 267, 264–277. Under special conditions, silence can give consent. I return to this below.

  51. 51.

    J. S. Mill, On Liberty, ch 1.

  52. 52.

    Catharine MacKinnon, Towards a Feminist Theory of the State (Cambridge MA: Harvard University Press, 1989), 148. And more generally: Susan Estrich Real Rape (Cambridge MA: Harvard University Press, 1984), and Stephen J. Schulhofer, Unwanted Sex: The Culture of Intimidation and the Failure of Law (Cambridge MA: Harvard University Press, 1998).

  53. 53.

    All my comments in the Section are restricted to the heterosexual context. I do not deny that gay men, and women, are raped or sexually assaulted by people of the same sex, yet we do need to think differently about sexuality and its morality in homosexual contexts. I defend that view in Leslie Green, ‘Pornographies’ (2000) 8 Journal of Political Philosophy 27.

  54. 54.

    See Susan Estrich Real Rape (Cambridge MA: Harvard University Press, 1984), and Stephen J. Schulhofer, Unwanted Sex: The Culture of Intimidation and the Failure of Law (Cambridge MA: Harvard University Press, 1998).

  55. 55.

    Sexual Offences Act 2003 (UK).

  56. 56.

    Rae Langton, Sexual Solipsism: Philosophical Essays on Pornography and Objectification (Oxford: Oxford University Press, 2009). For some doubts see Leslie Green, ‘Pornographizing, Subordinating, and Silencing,’ in R. Post, ed., Censorship and Silencing: Practices of Cultural Regulation (Los Angeles: Getty Research Institute, 1998) 285–311.

  57. 57.

    Dan M. Kahan, ‘Culture, Cognition, and Consent: Who Perceives What, and Why, in Acquaintance-Rape Cases,’ (2010) 158 University of Pennsylvania Law Review 729. In an experimental setting what matters most in determining whether people will judge that ‘no’ can mean ‘yes’ is what Kahan calls their ‘cultural style’—roughly, how conservative and sexist they are. The results are as one would expect, except perhaps for the fact that older, sexist women are the group most likely to think ‘no’ sometimes mean ‘yes’.

  58. 58.

    Matthew Waites, The Age of Consent: Young People, Sexuality, and Citizenship (Basingstoke, Palgrave Macmillan, 2005).

  59. 59.

    And this affects teens themselves. The Sexual Offences Act forbids anyone under 16 any sort of sexual activity; not only sexual intercourse but also ‘sexual ‘touching’ (‘with any part of the body’ or ‘with anything else,’ and ‘through anything.’) Guidance to the Crown Prosecution Service, however, suggests that under-16s should not be prosecuted for consensual sex. The unenforced prohibition is therefore presumably supposed to ‘send a message.’ But what, and to whom?

  60. 60.

    Why ‘no longer?’ See Deuteronomy 22:28–29; Numbers 31:18, Judges 19:2. Why ‘not officially?’ That question answers itself, as tens of thousands of raped and sexually abused children could testify and, we may hope, someday will.


For comments I thank Michelle Dempsey, Antony Duff, Massimo Renzo, and especially Donald Dripps, whose question provoked me to write this paper.

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Correspondence to Leslie Green.

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Green, L. Should Law Improve Morality?. Criminal Law, Philosophy 7, 473–494 (2013).

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  • Social morality
  • Consent
  • Rape
  • HLA Hart
  • Patrick Devlin
  • Paul Robinson