1 Baker v Canada (Minister of Citizenship and Immigration) [1999] 2 S.C.R. 817.

2 Suresh v Canada (Minister of Citizenship and Immigration) [2002] 1 S.C.R. 3.

3 R (on the application of Begum (by her litigation friend, Rahman)) (Respondent) v Headteacher and Governors of Denbigh High School (Appellants) [2006] UKHL 15.

4 Belfast City Council v Miss Behavin’ Ltd. [2007] 1 W.L.R. 1420.

5 Hart, H.L.A., “Positivism and the Separation of Law and Morals” (1958) 71 Harvard L.R. 593CrossRefGoogle Scholar; Fuller, Lon L., “Positivism and Fidelity to Law: A Reply to Professor Hart” (1958) 71 Harv.L.Rev. 630CrossRefGoogle Scholar.

6 Waldron, J., “The Core of the Case against Judicial Review” (2006) 115 Yale L.J. 1346CrossRefGoogle Scholar. Dworkin, R., Freedom's Law: The Moral Reading of the American Constitution (Harvard 1996)Google Scholar.

7 See the debates in Forsyth, C. (ed.), Judicial Review and the Constitution (Oxford 2000)Google Scholar.

8 A large and instructive exception is Summers, R.S., Form and Function in a Legal System: A General Study (Cambridge 2006)Google Scholar. Summers studies the “functional legal units” of a legal order and the formal features of each, such as the judiciary and the legislature, and the way the formal features structure both the operation of each and their interaction with each other. See Part One. My argument is much more limited, as it has to do only with the form of public law. Whilst I share much with Summers, in particular, the aim of showing the connection between form and substance (see pp. 61–63), I have a different view of the role of formalism in legal positivism and of the way in which law's compliance with criteria of form gives law a moral quality. In this second regard, I take more seriously than he does the wonderful quote from Jhering at p. 187 – “form is the twin sister of liberty, and the sworn enemy of the arbitrary” – as, unlike him, I think the idea in this quote is not only about constraining official power, but also about constituting the power that officials have. But the main difference is that, in my approach, the issue is not that legal positivism fails to notice the importance of legal form, but that it conceives form in a particular way because of the normative commitments of its tradition.

9 Weinrib, E.J., The Idea of Private Law (Harvard 1995)Google Scholar; Ripstein, A., Force and Freedom: Kant's Legal and Political Philosophy (Harvard 2009)CrossRefGoogle Scholar.

10 Allan, T.R.S., The Sovereignty of Law: Freedom, Constitution and Common Law (Oxford 2013), 128–31CrossRefGoogle Scholar.

11 Hart, “Positivism and the Separation of Law and Morals”, pp. 609–10.

12 Ibid.

13 Craig, P., “Formal and Substantive Conceptions of the Rule of Law: An Analytical Framework” (1997) P.L. 467Google Scholar.

14 Ibid., at p. 467.

15 Ibid.

16 Ibid., at pp. 468–69, emphasis in original.

17 Ibid., at p. 487.

18 Dworkin for much of his career hardly talked about the “rule of law” or “legality” and, when he did, it seemed to be little more than a synonym for “integrity”, where the integrity is a coherence constraint on what one should take the substantive morality implicit in the law of a particular system to be. See e.g. Dworkin, R., Law's Empire (London 1986), 93Google Scholar, and, for criticism, Dyzenhaus, D., “The Rule of Law as the Rule of Liberal Principle” in Ripstein, A. (ed.), Ronald Dworkin (Cambridge 2007), 56Google Scholar. Whilst I cannot go into this point here, I think that Dworkin's legal theory could be productively reconceived as a formal conception of the rule of law, thought this requires a rapprochement with Fuller which he always resisted. John Gardner argues that Craig is badly mistaken in supposing that theories of the rule of law can be divided between formal and substantive positions; “The Supposed Formality of the Rule of Law” in Gardner, J., Law as a Leap of Faith (Oxford 2012), 195, 198–204CrossRefGoogle Scholar. But Gardner fails to recognise the implications for his own legal positivist conception of the rule of law that follow from seeing the complex links between form, procedure, and substance, and, in these regards, Craig's analysis remains most helpful.

19 Raz, J., The Authority of Law: Essays on Law and Morality (Oxford 1979), 49–50CrossRefGoogle Scholar; Craig, “Formal and Substantive Conceptions of the Rule of Law”, p. 483.

20 Raz, The Authority of Law, pp. 47–48.

21 Hart, H.L.A., Essays on Bentham: Jurisprudence and Political Theory (Oxford 1982), 252–53CrossRefGoogle Scholar.

22 Hobbes, T., Leviathan, in Tuck, R. (ed.) (Cambridge 1996), 176Google Scholar.

23 Hart, Essays on Bentham, at p. 254.

24 Hart implicitly recognised this point when he seemed to express his openness to “soft” or “inclusive” legal positivism in the Postscript to Hart, H.L.A., The Concept of Law, 2nd ed. (Oxford 1994), 250Google Scholar.

25 Hobbes, Leviathan, p. 110.

26 Ibid., at p. 183.

27 See Dyzenhaus, D., “Hobbes on the Authority of Law” in Dyzenhaus, D. and Poole, T. (eds.), Hobbes and the Law (Cambridge 2012), 186CrossRefGoogle Scholar.

28 Though Hobbes insists with other early modern thinkers that the principles are also those that God must be taken to have willed.

29 Dyzenhaus, D., Hard Cases in Wicked Legal Systems: Pathologies of Legality (Oxford 2010, revised edition), ch. 8Google Scholar.

30 Craig, “Formal and Substantive Conceptions of the Rule of Law”, p. 467.

31 J. Raz, “The Rule of Law and Its Virtue”, in Raz, The Authority of Law, p. 210.

32 Ibid., at pp. 213–14.

33 Ibid., at p. 221.

34 Ibid.

35 These are set out in detail in Fuller, L.L., The Morality of Law (New Haven 1969, revised edition), ch. 2Google Scholar.

36 Ibid., at pp. 157–59.

37 Raz, “The Rule of Law and Its Virtue”, pp. 224–26.

38 Ibid., at pp. 215–18.

39 For example, Jeremy Waldron says that “we radically sell short the idea of the Rule of Law if we understand it to comprise a list like Fuller's list … without also including something like the procedural list …”, which on his own account has 10 principles; see Waldron, “The Rule of Law and the Importance of Procedure” in Fleming, J. (ed.), Getting to the Rule of Law (New York 2011), 3, 6–7Google Scholar.

40 Ibid., at p. 8.

41 See Fuller, The Morality of Law, p. 81: “This congruence may be destroyed or impaired in a great variety of ways: mistaken interpretation, inaccessibility of the law, lack of insight into what is required to maintain the integrity of a legal system, bribery, prejudice, indifference, stupidity, and the drive towards personal power. Just as the threats towards this congruence are manifold, so the procedural devices designed to maintain it take, of necessity, a variety of forms. We may count here most of the elements of ‘procedural due process’.”

42 Fuller, L.L., “The Forms and Limits of Adjudication” in Winston, K.I. (ed.), The Principles of Social Order: Selected Essays of Lon L. Fuller (Oxford 2001), 101Google Scholar.

43 Waldron, “The Rule of Law and the Importance of Procedure”, p. 11.

44 Ibid., at p. 15; Fuller, The Morality of Law, p. 162. In the second sentence, Waldron quoted from Fuller the words omitted are “to him” in Fuller's “convey to him”. This omission does rather weaken the point Fuller is making – that justification has to be to the person affected by the law.

45 Waldron, “The Rule of Law and the Importance of Procedure”, p. 15.

46 Fuller, “The Forms and Limits of Adjudication”, p. 111, emphasis added.

47 Ibid.

48 Ibid., at p. 114.

49 Hart, “Positivism and the Separation of Law and Morals”, p. 603.

50 Waldron, J., “Positivism and Legality: Hart's Equivocal Response to Fuller” (2008) 83 N.Y.U.L.Rev. 1135Google Scholar.

51 Hart, The Concept of Law, pp. 206–07.

52 Ibid., at p. 193.

53 Ibid., at p. 194.

54 Ibid., at pp. 194–200.

55 Ibid., at p. 199.

56 Ibid., at p. 205.

57 Fuller, L.L., Anatomy of the Law (Westport, CT 1976)Google Scholar, first published in 1968.

58 See Stone, M., “Legal Positivism as an Idea about Morality” (2011) 61 University of Toronto L.J. 313CrossRefGoogle Scholar. Stone's diagnosis of the problem is, I think correct, but his Kantian antidote, which argues that morality is incomplete without the law, shares with legal positivists the mistake of making morality prior to both politics and law.

59 Hart, The Concept of Law, p. 173.

60 For the distinction between “critical” and “positive”, see Hart, H.L.A., Law, Liberty, and Morality (Oxford 1962), 20Google Scholar.

61 For illuminating discussion of Hart's views about morality, see Cane, P., “Morality, Law and Conflicting Reasons for Action” [2012] C.L.J. 59CrossRefGoogle Scholar. And see more generally, Hart, The Concept of Law, pp. 167–84.

62 Hart, “Positivism and the Separation of Law and Morals”, pp. 60–61; Hart, The Concept of Law, pp. 27–29. For more detailed discussion, see Dyzenhaus, D. “Liberty and Legal Form” in Austin, L. and Klimchuk, D. (eds.), Private Law and the Rule of Law (Oxford 2014), 92Google Scholar.

63 Hart, The Concept of Law, p. 33.

64 Ibid., at pp. 28–33.

65 Hart, The Concept of Law, pp. 43–44, emphasis in original.

66 Ibid., at p. 43.

67 See Schmitt, C., Political Theology: Four Chapters on the Concept of Sovereignty, trans. Schwab, George (Cambridge, MA, 1988)Google Scholar and Loughlin, M., Foundations of Public Law (Oxford 2010)CrossRefGoogle Scholar.

68 Dworkin, R., Taking Rights Seriously, 3rd impression (London 1981), xiGoogle Scholar.

69 For a more elaborate argument to this effect, see Dyzenhaus, “Liberty and Legal Form”. In general, this kind of argument does presuppose the priority of the public law form and indeed might suggest that legal theory in general should be reconceived as a theory of public law along the lines of the German Staatsrechtslehre tradition. Instructive in this regard is Cane, P., “Public Law in The Concept of Law” (2013) 33 O.J.L.S. 649CrossRefGoogle Scholar.

70 Here I glide over a distinction between an individual's personal moral code and critical morality, where the latter seems to be in some sense public in that it has to do with standards that transcend any particular individual's personal code, without being reducible to convention. For discussion, see Cane, “Morality, Law and Conflicting Reasons for Action”.

71 Strictly speaking, this strategy works by interfering with procedural principles and that has the effect that legal subjects cannot access the law. But that effect removes the possibility of demanding that an official show a legal warrant for his action, which means that there is no law that binds him.

72 The leading account of this kind of Fullerian claim is Simmonds, N., Law as a Moral Idea (Oxford 2008)CrossRefGoogle Scholar. For exploration of similar ideas, see Waldron, J., “How Law Protects Dignity” (2012) 71 C.L.J. 200CrossRefGoogle Scholar and Rundle, K., “Form and Agency in Raz's Legal Positivism” (2012) 32 Law and Philosophy 767CrossRefGoogle Scholar.

73 See Williams, B., “Realism and Moralism” in Williams, B. (ed.), In the Beginning Was the Deed: Realism and Moralism in Political Argument (Princeton 2005), 1Google Scholar, at p. 5, emphasis in original.

74 Ibid., at pp. 1–3.

75 Ibid., at p. 3.

76 Ibid.

77 See his remarks about Habermas, ibid., at pp. 15–16.

78 For an insightful overview of Williams's position on politics and morality, see Freeman, S., “The Case against Moralism” (2014) 61 (12) New York Review of Books 50Google Scholar.

79 Raz, J., “Authority, Law, and Morality”, in Raz, J. (ed.), Ethics in the Public Domain: Essays in the Morality of Law and Politics (Oxford 1994), 194Google Scholar.

80 Hobbes, Leviathan, p. 194.

81 Ibid.

82 For example, in “Positivism and the Separation of Law and Morals”, p. 622, Hart mentions “the normally fulfilled assumption that a legal system aims at some form of justice colours the whole way in which we interpret specific rules in particular cases, and if this normally fulfilled assumption were not fulfilled no one would have any reason to obey except fear (and probably not that) and still less, of course, any moral obligation to obey”. He goes on to say that, if there were not some group that received the benefit of protection from the law, the system would “sink to the status of a set of meaningless taboos” and that “no one denied those benefits would have any reason to obey except fear and would have every moral reason to revolt”: ibid., at p. 624.

83 One important implication is that, when administrative officials perform the conversion process appropriately, the question for a reviewing court is not whether the court thinks the product is correct, but whether it is reasonable. In other words, judges must defer to reasonable decisions administrative decisions about what legality requires. See e.g. Dyzenhaus, D., “Dignity in Administrative Law: Judicial Deference in a Culture of Justification” (2012) 17 Review of Constitutional Studies 87Google Scholar.