¹ A.W.B. Simpson, Reflections on The Concept of Law (Oxford 2011), 1.

² H.L.A. Hart, The Concept of Law (Oxford 1961). References are to the 2^nd edition, edited by P. Bulloch and J. Raz and published in 1994. The 2^nd edition reprints the 1^st edition with the addition of a posthumous Postscript based on material written but by Hart but not published in his lifetime. The book has been translated into 17 languages, and more than 50,000 copies of the 2^nd edition have been sold since 1998.

³ The separation thesis must be distinguished from the thesis that there is no necessary conceptual connection between law and morality. Hart did not subscribe to the “no necessary connection” thesis. Indeed, it is inconsistent with the separation thesis, which entails that state law is necessarily subject to moral evaluation. Hart also believed that there is a “naturally” necessary connection between law and morality, which is found in the minimum content of natural law (CL ch. 9). To mark the difference between the separation thesis and the “no necessary connection” thesis, some scholars now associate Hart with the “separability” thesis to the effect that law and morality are “separable” rather than separate. Concerning Hart's motivation in adopting the separation thesis see CL 207–212; see also Soper, P., “Choosing a Legal Theory on Moral Grounds” (1986) 4 Philosophy and Social Policy 32CrossRefGoogle Scholar; F. Schauer, “Fuller on the Ontological Status of Law” in W.J. Witteveen and W. van der Burg (eds.), Rediscovering Fuller: Essays on Implicit Law and Institutional Design (Amsterdam 1999); L. Murphy, “The Political Question of the Concept of Law” in J. Coleman (ed.), Hart's Postscript: Essays on the Postscript to the Concept of Law (Oxford 2001).

⁴ The leading modern exponent of this approach is John Finnis: J. Finnis, Natural Law and Natural Rights, 2^nd edn. (Oxford 2011).

⁵ E.g. N. Simmonds, Law as a Moral Idea (Oxford 2007); L.L. Fuller, The Morality of Law (New Haven 1964).

⁶ E.g. R. Dworkin, Law's Empire (London 1986), 93: “the most abstract and fundamental point of legal practice is to guide and constrain the power of government. Law insists that force not be used or withheld … except as licensed or required by individual rights and responsibilities flowing from past political decisions about when collective force is justified.”

⁷ According to Martin Stone, it is the first, rather than the second, of these assumptions that distinguishes the separation thesis from soft natural law: “Legal Positivism as an Idea about Morality” (2011) 61 University of Toronto L.J. 313. He argues that (to the extent that law and morality share common concerns) soft natural lawyers think of law as a “part of” (ibid., p. 341) or, perhaps, an extension or realisation or concretisation of morality; whereas separationists conceive of it as an instrument or application of morality. See also R Dworkin, Justice for Hedgehogs (Cambridge, Mass. 2011), ch.19; concerning Kant's similar view see A. Ripstein, Force and Freedom: Kant's Legal and Political Philosophy (Cambridge, Mass. 2009), 223–5, 255–6. In Stone's account, for soft natural lawyers, morality is incomplete without law. By contrast, for separationists, morality is self-sufficient or, as he puts it, “self-standing” (ibid., p. 319). Stone particularly associates the separationist view of morality with the development of utilitarianism as a comprehensive moral theory and decision-procedure. The idea that morality can be fully understood without taking account of law pervades modern moral philosophy.

⁸ The topic falls between two stools: most philosophers who discuss the nature of morality are uninterested in law while legal theorists are typically more concerned with the normative relationship between law and morality than with the descriptive relationship.

⁹ Hart actually refers to “secondary” rules that empower the officials rather than to officials. But the significance of secondary rules is that they create and empower the institutions that administer the regime of primary rules.

¹⁰ Of course, there are many types of social institutions in addition to those identified by Hart as characteristic of law. In this paper, the terms “institutional” and “institutionalised” refer only to characteristically legal institutions. Ironically, Hart showed very little interest in actual legal institutions and how they operate in practice: Lacey, N., “Analytical Jurisprudence versus Descriptive Sociology Revisited” (2006) 84 Texas Law Review 945Google Scholar; “Out of the ‘Witches’ Cauldron'? Reinterpreting the Context and Reassessing the Significance of the Hart-Fuller Debate” in P. Cane (ed.), The Hart-Fuller Debate in the Twenty-First Century (Oxford 2010).

¹¹ For a suggestive discussion of the relationship between habit, custom and law see J.B. Murphy, “Habit and Convention at the Foundation of Custom” in A. Perreau-Saussine and J.B. Murphy, The Nature of Customary Law: Legal, Historical and Philosophical Perspectives (Cambridge 2007). For the criticism that Hart's account of custom is purely structural see A.W.B. Simpson, Reflections on The Concept of Law, p. 175.

¹² Hart contrasted ideals with duties (CL 182), aspiration and supererogation with obligation. It is not clear why he thought it important to include personal ideals in his account of morality since they have no clear analogy in his account of law, which is social, not personal, and rooted in obligation, not aspiration. Nor is it clear why he limited idiosyncratic, personal morality to ideals. An individual might, for instance, consider vegetarianism an obligation for themselves but not for others. Perhaps more importantly for present purposes, it is not clear whether or to what extent personal morality shares with positive and critical morality the four characteristics listed later in this paragraph – more especially, the last two. Social ideals have an important place in some concepts of law and certain accounts of the normative relationship between law and morality. See, e.g., the work of Simmonds and Fuller cited note 5 above. See also C.A.J. Coady, Messy Morality: The Challenge of Politics (Oxford 2008), 67–70.

¹³ R. Dworkin, Taking Rights Seriously (London 1977), 53–58. See also G.J. Warnock, The Object of Morality (London 1971), ch. 5.

¹⁴ See also R.B. Brandt, A Theory of the Right and the Good (Oxford 1979), 172. It does not follow, of course, that social practices and institutions do not play a part – indeed, a very important part – in the formation of individuals' convictions and even their “personal ideals” (see e.g. P.F. Strawson, “Social Morality and the Individual Ideal” in G. Wallace and A.D.M. Walker, The Definition of Morality (London 1970)).

¹⁵ See also N. Cooper, “Two Concepts of Morality” in The Definition of Morality, esp. pp. 84–88. According to James Wallace, the philosopher John Dewey considered customary morality to be prior to critical morality: J.D. Wallace, Moral Relevance and Moral Conflict (Ithaca 1988), 73–6.

¹⁶ In Hart's revised view, the “social rule” or “practice” account of norms fails to provide “a sound explanation of morality, either individual or social” (CL 256). The extent to which “morality” consists of “rules” is an ongoing topic of debate amongst philosophers that Hart does not address.

¹⁷ See P. Devlin, The Enforcement of Morals (Oxford 1965) (the Maccabaean Lecture is reproduced in Chapter 1); H.L.A. Hart, Law, Liberty and Morality (Oxford 1963).

¹⁸ As Bob Goodin neatly puts it: Goodin, R.E., “An Epistemic Case for Legal Moralism” (2010) 30 Oxford Journal of Legal Studies 615CrossRefGoogle Scholar.

¹⁹ According to Hart, Devlin later reverted to the view that “the law [on homosexuality] ought to be altered”: Sugarman, D., “Hart Interviewed: HLA Hart in Conversation with David Sugarman” (2005) 32 Journal of Law and Society 267, 285CrossRefGoogle Scholar.

²⁰ Following Hart's lead, in most jurisprudential discussions of the concept of law, morality is identified by its “form” as opposed to its “substance”. The substance of morality plays a larger role in theoretical discussions of particular areas of the law, such as criminal law and contract law.

²¹ Hart said much about what he called “the minimum content of natural law” (CL ch 9). He argued that as a matter of “natural necessity”, both morality and law address certain obstacles to successful social life. The claim that morality is partly a function of human physical and mental characteristics and the natural environment in which we live is, no doubt, relatively uncontroversial; but how much of morality can be explained in this way certainly is not. For an expansive view see J. Finnis, Natural Law and Natural Rights, 2^nd edn (Oxford 2011). This is a key question in contemporary evolutionary and cognitive science. See e.g. R.A. Hinde, Why Good is Good: The Sources of Morality (London 2002); J. Mikhail, “Plucking the Mask of Mystery from Its Face: Jurisprudence and HLA Hart” (2007) 95 Georgetown Law Journal 733.

²² E.g. T.M. Scanlon, What We Owe to Each Other (Cambridge, Mass. 1998), 171–2.

²³ “[I]t would be absurd to deny the title of morality to emphatic social vetoes” such as sexual taboos: CL 175. See also CL 182.

²⁴ But not Devlin: Law, Liberty and Morality (note 17 above), pp. 19–20.

²⁵ Ibid., pp. 22–4.

²⁶ Taking Rights Seriously (note 13 above), p. 255.

²⁷ Ibid., p. 248.

²⁸ Ibid., pp. 248, 250.

²⁹ C. McMahon, Reasonable Disagreement: A Theory of Political Morality (Cambridge 2009), 9.

³⁰ E.g. Simpson, Reflections, note 1 above, pp. 157–60.

³¹ B.Z. Tamanaha, A General Jurisprudence of Law and Society (Oxford 2001).

³² For a suggestive comment by Hart along similar lines see Sugarman, “Hart Interviewed” (n 19 above), 291. For a related point see Krygier, M., “The Concept of Law and Social Theory” (1982) 2 Oxford Journal of Legal Studies 155, 159–61CrossRefGoogle Scholar. By adopting a concept of morality as autonomous judgment, Neil MacCormick is able to establish a “conceptual” distinction between law and morality: N. MacCormick, Institutions of Law: An Essay in Legal Theory (Oxford 2007), ch. 14.

³³ For an extended argument along these lines see J. Shklar, Legalism: Law, Morals and Political Trials (Cambridge, Mass. 1986), 39–64.

³⁴ There are many versions and varieties of both moral realism and moral constructivism. My only concern here is with Hart's unwillingness to commit himself to any version of either. Christopher McMahon develops a view he calls “moral nominalism”, “intermediate” between realism and constructivism, to explain the important phenomenon of reasonable moral disagreement, to which Hart paid little or no attention and which, McMahon says, neither realism nor constructivism can adequately explain: McMahon, Reasonable Disagreement (note 29 above). Central to nominalism is the idea that moral ideas evolves and can change.

³⁵ Because this phrase appears in the Postscript to The Concept of Law, I assume that by “moral principles” Hart means personal moral convictions as opposed to conventional morality. Hard positivists need not and do not reject Hart's view that conventional norms can be part of the law if the rule of recognition so provides: CL 44–8.

³⁶ I assume for the sake of the argument that freedom of speech, equality, due process and so on are “moral” issues. However, it is arguable that framing the debate between hard and soft positivists in terms of the relevance of “morality” to the validity of law raises the stakes unnecessarily. Instead, the difference between the two positions might be said to concern whether the content of a law (as opposed to its source) can affect its validity. This reading of the debate is consistent with the argument made in the next paragraph below. In this light, a provision of the type we are considering would authorise judges, in assessing its validity, to take account of the content as well as the source of a law without raising any issue about the “status” of the relevant “substantive values”, for conformity with which the law is to be tested.

³⁷ Hart may have been attracted to soft positivism because it seems descriptively superior to hard positivism. As a matter of legal doctrine, when legislation is held unconstitutional it is invalidated with retrospective effect, not deprived of effect prospectively. On the other hand, hard positivism is likely to be normatively attractive to those who distrust judicial power or who think that citizens should be able to identify what the law is without recourse to substantive moral reasoning.

³⁸ Matthew Kramer is a soft positivist who commits himself to the view that there are objective moral truths and that it is such truths that the sort of provision we have been discussing incorporates into the law: M.H. Kramer, Where Law and Morality Meet (Oxford 2004), ch 2. However, he also accepts, of course, that judges are morally fallible. His view is that a judge who makes a mistake about what morality requires changes the pre-existing law while a judge who correctly identifies what morality requires applies the pre-existing law. Kramer argues that the interpretation of soft positivism I suggest here “can very easily be extended into an audacious form of rule-scepticism” in relation to the application as opposed to the ascertainment of law (ibid., 119). This conclusion seems to me to confuse moral reasoning with textual interpretation or, at least, to rest on a highly formal, rule-based understanding of morality.

³⁹ J. Waldron, “The Irrelevance of Moral Objectivity” in Law and Disagreement (Oxford 1999). MacCormick apparently makes a similar point when he argues that for realists, autonomy is morally rather than metaphysically relevant to their moral lives (MacCormick, note 32 above, p. 250). Unlike Hart, MacCormick appears to have committed himself to some version of constructivism.

⁴⁰ See e.g. Balcombe, Lord Justice, “Judicial Decisions and Social Attitudes” (1994) 84 Proceedings of the British Academy 209, 229Google Scholar; Bingham, Lord of Cornhill, “The Judges: Active or Passive” (2006) 139 Proceedings of the British Academy 55Google Scholar, 70. For an extended scholarly argument to this effect see M.A. Eisenberg, The Nature of the Common Law (Cambridge, Mass. 1988).

⁴¹ Cane, P., “Taking Disagreement Seriously: Courts, Legislatures and the Reform of Tort Law” (2005) 25 Oxford Journal of Legal Studies 393CrossRefGoogle Scholar.

⁴² Johnson, C.D., “Moral and Legal Obligation” (1975) 72 Journal of Philosophy 315, 329–31CrossRefGoogle Scholar argues, with particular reference to promising, that in both law and morality importance is related to the level of abstraction and, conversely, specificity, at which their respective “requirements” are stated – the more abstract the more important, the more specific the less important.

⁴³ Note 17 above, p. 22.

⁴⁴ Ibid.

⁴⁵ “Throughout the history of philosophy, by far the most popular candidate for the position of the moral point of view has been self interest”: K. Baier, The Moral Point of View: A Rational Basis of Ethics (Ithaca, NY 1958), p. 187. See also, e.g., S. Scheffler, Human Morality (New York 1992), ch. 2; Leiter, B., “Nietzsche and the Morality Critics” (1997) 107 Ethics 250, esp. pp. 259–60CrossRefGoogle Scholar, 272.

⁴⁶ See, e.g., M. Timmons, Moral Theory: An Introduction (Lanham, MD 2002), 134–5.

⁴⁷ Hart treats this criterion inconsistently, in one place offering it as a point of similarity between law and morality, not difference: CL 172, where he summarises five “striking similarities between moral and legal rules of obligation”.

⁴⁸ For the suggestion that the legal principle that promises should be kept is just as immune to deliberate change as its moral analogue see Johnson, “Moral and Legal Obligation” (note 42 above), pp. 322–4. In Johnson's view, the important distinction is not between law (changeable) and morality (immune to change) but between fundamental principles (immune to change) and specific rules and obligations (changeable).

⁴⁹ Indeed, G.E.M. Anscombe famously argued that the concept of morality only makes sense within a religious framework: Ethics, Religion and Politics: The Collected Philosophical Papers of G.E.M. Anscombe, Volume Three (Oxford 1981, ch 4 (“Modern Moral Philosophy”). For a discussion of the role that authority might play in secular morality see S. Fleischacker, The Ethics of Culture (Ithaca, NY 1994), esp. chs. 3 and 4.

⁵⁰ G. Harman, The Nature of Morality: An Introduction to Ethics (New York 1977), 112.

⁵¹ Of course, judicial reasoning is substantively constrained by institutional factors in a way that the moral reasoning of individuals is not.

⁵² To similar effect: Warnock, The Object of Morality (note 13 above), pp. 49–50.

⁵³ More generally, this tendency may explain why philosophers deny the possibility of strict moral liability: Watkins, J., “Responsibility in Context” (2006) 26 Oxford Journal of Legal Studies 593CrossRefGoogle Scholar, 606.

⁵⁴ Wallace, Moral Relevance and Moral Conflict (note 15 above), p. 12. Wallace argues that solving moral conflicts requires active interpretation and adaptation of moral rules and principles in a way that changes existing rules and principles and generates new ones. Morality, he asserts, is “an intellectual and cultural achievement” (ibid, 53) and a matter of “learned dispositions” (ibid., p. 55).

⁵⁵ To similar effect: C.E. Larmore, Patterns of Moral Complexity (Cambridge 1987), 149–50.

⁵⁶ T. Honoré, “Can and Can't” (1964) 73 Mind 463; reprinted in T. Honoré, Responsibility and Fault (Oxford 1999). I am leaving aside the issue of causal determinism. Whatever the truth may be at the micro-level of physical processes, at the meso-level of practical reasoning and action there is no good reason to ignore the lived experience of freedom and control.

⁵⁷ Fuller's famous list of pathologies of rules includes “requiring conduct beyond the powers of the affected party”: L.L. Fuller, The Morality of Law, revised edn. (New Haven 1969), 39.

⁵⁸ At any rate, accounts of the morality of obligation as opposed to the morality of aspiration: see n 12 above. One exception that I know of is Bernard Gert's account of “common morality”, which he defines as “the moral system that most thoughtful people use, usually implicitly, when they make moral decisions and judgments”: B. Gert, Common Morality: Deciding What to Do (Oxford 2004), v. In Gert's scheme, the ultimate normative standard is “rationality” (ibid., pp. 91–5); and (he says) while it is never irrational to act morally, it may be rational to act immorally. Gert's view is explained by the fact that “common morality” is a substantive, not a formal concept. According to Gert, the basic principle of common morality is to “do no harm”. This understanding of morality also leads him to draw a distinction between religious principles about right and wrong, good and bad, virtue and vice on the one hand, and moral principles on the other (ibid., p. 4).

⁵⁹ Cf Scheffler, Human Morality (note 45 above), p. 12: “a shared reference point for the formulation and adjudication of challenges to existing institutions and practices more generally”.

⁶⁰ Or even that it is male or female: Criscuoli, G., “Is the Common Law Masculine or Feminine?” (1981) 1 Oxford Journal of Legal Studies 305CrossRefGoogle Scholar.

⁶¹ For this reason, amongst others, Hart resisted classification of international “law” as (international) morality: CL 227–32.

⁶² In the philosophical literature there is much discussion of a different question of whether and the extent to which moral reasons for action override or, on the contrary, accommodate reasons of self-interest (and, perhaps, some other types of “non-moral” reasons). See note 45 above. There is a similar debate about the relationship between moral reasons and reasons of public interest: P. Cane, Responsibility in Law and Morality (Oxford 2002), 276–7; see also Hart's discussion of the relationship between “justice” and “social/public/common good” (CL 166–7). The point I am making in the text assumes that the question of what reasons are moral reasons has already been answered. Under a theory that allows reasons of self-interest to trump moral reasons, legal reasons would presumably trump reasons of self-interest. One view of moral reasons for action is that they are “all-things-considered” reasons. So understood, morality would trump law as a matter of definition: Alexander, L. and Schauer, F., “Law's Limited Domain Confronts Morality's Universal Empire” (2007) 48 William and Mary Law Review 1579Google Scholar.

⁶³ This way of presenting the issue will not appeal to those who think that all genuine reasons for action are moral. They might prefer a formulation in terms of a conflict of the moral reasons provided by the law and moral reasons apart from the law. See note 6 above.

⁶⁴ Remember that this statement refers to the function of morality in individuals' practical reasoning. In a moral theory that distinguishes between conventional, positive morality on the one hand and individual, critical morality on the other, critical morality provides ultimate standards for assessing positive morality as much as other conventional normative systems.

⁶⁵ Honoré, T., “The Dependence of Morality on Law” (1993) 13 Oxford Journal of Legal Studies 1CrossRefGoogle Scholar.

⁶⁶ Even legal norms that are morally “arbitrary” in the sense that the norm chosen (e.g. drive on the left) is no more or less acceptable than some alternative (e.g. drive on the right) so that the choice between them is of “no intrinsic importance” (CL 229–30) may provide moral reasons for action. Hart believed that morality “logically” cannot be arbitrary in this sense (CL 229). However, if morality is understood not only to require and prohibit conduct but also to permit conduct that it neither requires nor prohibits, it is logically possible that in any particular situation several courses of conduct may be of equal moral value so that none is morally preferable to any alternative.

⁶⁷ I hope that this account of the relationship between law and moral reasoning, both “everyday” and “philosophical”, is an improvement on the account I gave in Responsibility in Law and Morality, which was fairly criticised by Watkins, Jeremy, “Responsibility in Context” (2006) 26 Oxford Journal of Legal Studies 593CrossRefGoogle Scholar.

⁶⁸ I am not sure whether Alexander and Schauer (note 62 above) go quite as far as this.

⁶⁹ Finnis, op. cit. note 4 above, p. 14.

⁷⁰ Simmonds, op. cit. note 5 above.