10 Positivism after Hart

(9.1) Introduction

HLA Hart made seminal contributions to the positivist philosophy of law. He broke away from classical positivism’s reliance on empiricism and the so-called ‘command theory’ of law, and instead postulated the idea of laws as rules, and transformed our perception of rules by highlighting their internal as well as external aspects. Furthermore, he classified rules as primary and secondary, the latter defined as rules about primary rules, and classified into three types, viz. rules of recognition, change, and adjudication. He then postulated that legal systems must have an ultimate rule of recognition, whose existence can be neither proved nor disproved, but only accepted as a rule by officials, through convention as it were. Not surprisingly, this provoked much controversy, particularly from Hart’s staunchest detractors such as Dworkin.

Interestingly, Hart’s insights have also served as a basis for much new thinking within the framework of positivism. These have emerged also as a response by adherents of positivism (largely though not exclusively students of Hart) to criticisms levelled by detractors. This lesson is dedicated to such developments, that is, developments within positivist thought undertaken in the wake of Hart’s seminal contributions. Here we discuss three selected such developments.

(9.2) Substantive and Methodological Positivism

(9.2.1) Perry’s Thesis

The term ‘methodological positivism’ has been prevalent for some time in other disciplines such as sociology.1 Its use in jurisprudence, however, seems to have originated with the theorist Stephen Perry. In a 1996 article2 that may be described as an extended review of WJ Waluchow’s Inclusive Legal Positivism,3 he makes the following claim: ‘Waluchow is, like H.L.A. Hart, both a methodological and a substantive positivist. (Also like Hart, he does not always distinguish as clearly as he might between these two types of positivist theory.)’4 Be that as it may, Perry himself does not specify here how the two are different. It is in another article, first published in 19985 and then subsequently included in the

1See e.g. G Steinmetz, ‘American Sociology beforeand after World War II: The (Temporary) Settling of a Disciplinary Field’ in C Calhoun (ed), Sociology in America: A History (University of Chicago Press 2007) 314, 316.

2SR Perry, ‘The Varieties of Legal Positivism’ (1996) 9 Canadian Journal of Law and Jurisprudence 361.

3WJ Waluchow, Inclusive Legal Positivism (OUP 1994). We shall discuss this work more extensively in Section 4 of this lesson.

4Perry (n 2) 362.

5SR Perry, ‘Hart’s Methodological Positivism’ (1998) 4 Legal Theory 427.

book Hart’s Postscript,6 that he outlines their difference. He defines substantive positivism as ‘the view that there is no necessary connection between morality and the content of law.’7 Methodological positivism, on the other hand, entails ‘the view that legal theory can and should offer a normatively neutral description of a particular social phenomenon, namely law’, that is, the claim that ‘there is no connection, necessary or otherwise, between morality and legal theory.’8 Perry also advances the claim that the respective claims of the two forms are ‘at least on the surface, logically independent’ and cites as examples Hobbes and Bentham who ‘employed normative methodologies to defend versions of substantive positivism … .’9 In other words, substantive positivism can be treated as a restatement of the separability thesis, viz. that there is no necessary connection between law and morality, while methodological positivism suggests that explanations of legal phenomena can be generated from without having to adopt any moral position.

In a way, this is a throwback to Hart’s own theoretical contributions, and how they may be observed to have changed over time. Back in 1961, in the Concept of Law as it originally stood, he had defined positivism in the following terms: ‘Here we shall take Legal Positivism to mean the simple contention that it is in no sense a necessary truth that laws reproduce or satisfy certain demands of morality, though in fact they have often done so.10 This is a clear enunciation of the separability thesis, that is, a separation between morals and law itself (and not the study of law), and hence can be understood as an expression of what Perry calls substantive positivism. On the other hand, in the postscript added to the 1994 second edition, he advanced the claim that ‘My aim in this book was to provide a theory of what law is which is both general and descriptive.’11 He characterised ‘general’ as ‘not (being) tied to any particular legal system or culture’ in its endeavour of generating an ‘explanatory and clarifying account of law’.12 By ‘descriptive’ he meant that his endeavour is ‘morally neutral and has no justificatory aims: it does not seek to justify or commend on moral or other grounds the forms and structures which appear in my general account of law …

.’13 Here his emphasis lies on the generation of a general and descriptive theory of law, that is, the study of law rather than law itself. In this sense, then, this perspective can be considered an expression of methodological positivism. Perry also agrees that this claim is ‘very good evidence that he meant to adopt a framework of methodological positivism.’14

6SR Perry, ‘Hart’s Methodological Positivism’ in J Coleman (ed), Hart’s Postscript (OUP 2001) 311 (subsequent references to this work are to this version).

7ibid 311.

8ibid.

9ibid.

10HLA Hart, The Concept of Law (2nd edn, OUP 1994) 185-86.

11ibid 239.

12ibid.

13ibid 240.

14Perry (n 6) 312.

The story does not end there. Perry identifies two varieties of methodological positivism, namely what he terms the ‘descriptive-explanatory method’ and the ‘method of conceptual analysis’.15 He then claims that only the first amounts to a positivist (that is, morally neutral) theory; the second he contends is nothing but a form of Dworkin’s interpretive approach.16 But first, what are these two forms of methodological positivism?

Perry begins by postulating that there are two possibilities how we may identify a social phenomenon as law. The first is to study it from an external, objective point of view, that is, something like a scientist observing a natural phenomenon. This is what he calls the descriptive-explanatory approach. The second possibility involves us analysing ‘our own concept of law’, that is, what we as participants inside a legal system understand by the term ‘law’. This entails examining our own social practices and how we categorise some as law, and so on.17 Such an approach seems akin to the hermeneutic or ‘internal-viewpoint’ approach Hart advocated in his rejection as ‘useless’ of a science-derived empirical methodology for the study of law.18

As such Perry agrees that Hart’s method is not of the descriptive-explanatory type, though he does discern elements of the latter in Hart’s philosophy (such as his use of the term ‘descriptive sociology’ to characterise his theory of law).19 Hence he ultimately classifies Hart’s methodology as ‘conceptual analysis’ of a singular type, that is, conceptual analysis from an external rather than internal point of view. This appears to pose a problem. Perry acknowledges that a purely descriptive-explanatory approach can be ‘general’ i.e. normatively neutral in character. But, he asks, ‘What does it mean to say that legal theory is general when your methodology is some form of conceptual analysis?’20 Perry’s response is to indicate that Hart’s theory is not really as general as it is claimed to be.

To start with, Hart distinguishes ‘modern municipal’ legal systems from more primitive ones. But what is the basis on which he does so? Perry points out that Hart invokes for this purpose the English legal system and others ‘which are broadly similar in structure in spite of important differences.’21

From this he infers that Hart’s theory is ‘local’ (as opposed to ‘general’) in a way similar to Dworkin’s theory is, and concludes from there that Hart’s and Dworkin’s methodologies ‘lose the appearance of an unbridgeable gulf.’22 Perry next characterises as an ‘evaluative claim’ Hart’s view that Hart’s opinion that a regime exclusively made of primary rules has defects which are removed by

15ibid.

16ibid 312-13.

17ibid 313-14.

18HLA Hart, Essays in Jurisprudence and Philosophy (OUP 1983) 13.

19Perry (n 6) 314-15.

20ibid 315.

21ibid 316-17, referring to Hart (n 10) 3.

22ibid 317.

incorporating secondary rules particularly the rule of recognition.23 This is not entirely without precedent. Stephen Guest, for example, contends (somewhat tenuously) that Hart’s distinction between primitive and modern municipal legal systems implies that it is in some sense good, i.e. morally good, to understand the second to be superior to the first.24

But how does Perry substantiate his contention that Hart’s external conceptual analysis approach is inadequate? To cut a long story short, he does so by first claiming that ‘Viewed in methodological terms, then, Hart’s project appears to be to clarify, from an external perspective, our shared concept of law, focusing in particular on the idea that law purports to bind us through authoritative acts.’ He then identifies three related parts in which such a theory can be divided, namely

(a) a ‘general account of obligation’; (b) legal concepts such as authority, state, legislation etc., and finally (c) analysis of the concept of law itself.25 Next he takes up each concept separately, and examines how Hart treats it. In each case, he finds Hart’s treatment to be inadequate. For example, Hart’s account of obligation cannot really be considered an analysis. This is because ‘It does not offer a normative account as to when, if ever, social rules do really create obligations, as opposed to the perception of obligations.’26 Hart’s observations about people regarding themselves as obligated does not elucidate whether or not they are in fact obligated. Hence since Hart’s account of obligation is merely a descriptive statement that some members of a group at certain times regard themselves as obligated, it ‘cannot be regarded as a proper analysis’. Perry concludes by saying that ‘This statement [i.e. about members of a group regarding themselves as obligated] uses rather than analyses the concept of obligation.’27 Hart’s accounts of the other parts are also similarly scrutinised and found to be inadequate. For example, ‘As in the case of Hart’s account of obligation, it is not clear that his account of the concepts of authority, validity, and so on is in any significant sense properly designated an analysis. This is so, at least, as long as he insists on sticking with an external, purely descriptive theoretical perspective.’28

Perry then concludes by making the important claim that issues of the law’s authority etc. can be resolved either by taking a sceptical point of view, that is, by claiming the law does not and cannot give rise to obligations, or by attributing a function to law and then examining how these functions could provide those within the legal system certain reasons for actions that they would otherwise not have.29 But this effectively amounts to Dworkin’s interpretivist attitude outlined

23ibid 323.

24Stephen Guest, ‘Two Strands in Hart’s Concept of Law: A Comment on the Postscript to Hart’s The Concept of Law’ in Stephen Guest (ed) Positivism Today (Dartmouth Publishers 1996) 29, 29-30.

25ibid. 331.

26ibid. 334.

27ibid. 334-35.

28ibid. 336.

29ibid. 348.

in Law’s Empire.30 Which in turn connects to Dworkin’s famous characterisation of ‘justification’ as ‘concerning how to make the best possible moral sense of a practice, from the participants’ point of view.’31 In other words, internal conceptual analysis of these legal notions from a non-sceptical perspective compels taking into account the purpose of law, and interpreting it in the ‘best possible moral sense’.

(9.2.2) Positivist Responses to Perry

Not surprisingly, this assertion provoked much debate, and much controversy. Leighton Moore’s extensive rebuttal32 contends that Perry misunderstood Hart’s objective: ‘The main problem with Perry’s argument, as I see it, is that it too hastily rejects the possibility that Hart’s primary intention was to describe legal institutions rather than to make explicit what we already subjectively understand by terms such as “law” and “legal system.”’33 He also claims that Perry’s appreciation of internal conceptual analysis is both different from34 and narrower than Hart’s.35 More interestingly, Hart himself laid down the foundations for a rebuttal. While his rejection of empiricism and scientific method has already been referred to,36 in the postscript to The Concept of Law he distinguished between describing an evaluation (including a moral evaluation) and endorsing it.37 Hence it is entirely possible for a theory to take into account Dworkin’s functions of law etc., and still remain general, that is, not committed to any specific normative position.

Perhaps much of the controversy attaching to this issue can be attributed to a conflation between what is desirable and what is moral. Guest could be said to be a prime culprit in this regard.38 Julie Dickson expresses disagreement with what she perceives as Perry’s thesis, namely that conceptual-analysis perspectives on the law’s normativity necessitates moral evaluation.39 She contends instead that a process of ‘indirect evaluation’ can be used to analyse the notion Perry alludes to. By this she means that an ‘indirectly evaluative proposition such as ‘X is important” does not entail a directly evaluative proposition that this same X is good.’40 She takes the example of an agnostic observing a Roman Catholic mass.41 Such an observer may evaluate which rituals are important or desirable in the light of the mass’s purposes and objectives. But this will not amount to endorsing

30R Dworkin, Law’s Empire (Harv UP 1986) 47.

31See Perry (n 6) 349.

32L Moore, ‘Description and Analysis in the Concept of Law: A Response To Stephen Perry’ (2002)

8 Legal Theory 91.

33ibid 93.

34ibid 94.

35ibid 96.

36See n 18 and accompanying text.

37Hart (n 10) 242.

38See n 24 and accompanying text.

39J Dickson, Evaluation and Legal Theory (Hart Publishing 2001) 37.

40ibid 64.

41ibid 67-68.

any such ritual as morally desirable or undesirable, or otherwise good or bad. Indeed, the observer is free to not adopt any position on this.42

Brian Leiter tackles the desirable/moral conflation by making a distinction between epistemic and moral values: the first category entails norms like evidentiary adequacy, simplicity, explanatory consilience and other ‘truth-conducive desiderata’ which are desirable not because of their moral content but because they help us acquire knowledge.43 According to him, understanding notions like obligation and authority in terms of these epistemic values is enough, and any middle-ground between descriptive and normative (such as Dickson’s indirect evaluation) is not really necessary or called for.

(9.3) Coleman’s Conception of Negative and Positive Positivism

Jules Coleman’s distinction between negative and positive positivism is important because in many ways it helps us understand later concepts like Waluchow’s inclusive positivism. The idea first appeared in a 1982 article,44 and was subsequently included in his book Markets, Morals, and the Law.45 Just like Perry developed his ideas by using Hart as a target, so did Coleman expound on his perspectives through a target, in this case his perception of Dworkin’s claims about Hart’s positivism.

Coleman begins from Hart’s rule of recognition. This he describes as ambiguous, since it features both epistemic and semantic senses. In its first sense, the rule is used as a standard to identify, validate or discover a law within a legal system. In the second sense, the rule specifies the criteria to be satisfied by a norm before being recognised as a law. He further advances the possibility that a rule may be a rule of recognition in one but not the other sense, since ‘the rule one employs to determine the law need not be the same rule as the one that makes law determinate.’46 Regrettably, he does not further dilate on this issue or provide any example.

Turning to the separability thesis, he points out that it needs to be distinguished from the claim that ‘the law of a community is one thing and its morality another.’ The latter he describes as ‘seriously ambiguous’, and construable in at least three different senses: (a) that there exists no convergence between a community’s law and morality; (b) that laws of a community can be identified without reference to morality; or (c) that in no community can a moral proposition be used as a truth condition for any proposition of law. The last he claims is one Dworkin is ‘anxious

42ibid 69.

43B Leiter, ‘Beyond the Hart/Dworkin Debate: The Methodology Problem in Jurisprudence’

(2003) 48 American Journal of Jurisprudence 17, 34-35.

44JL Coleman, ‘Negative and Positive Positivism’ (1982) 11 Journal of Legal Studies 139.

45JL Coleman, Markets, Morals, and the Law (OUP 1998) 3-27.

46ibid 5.

to ascribe to positivism’,47 and the validity of this ascription commands some prominence in Coleman’s exegesis.

Coleman characterises as negative positivism a form of positivism where the rule of recognition is ‘constrained’ by the separability thesis, that is, a belief that at least one legal system may be conceived where the rule of recognition does not entail any moral criterion. On the other hand, positive positivism, which forms Dworkin’s favourite target, involves construing the rule of recognition in terms of the belief that a moral condition cannot ever determine the legal validity of a norm. The point of this is, negative positivism is not threatened by Dworkin’s claims about principles counting as legal norms in hard cases. ‘Much of the debate between positivists and Dworkin appears rather foolish, unless there is a version of positivism that makes Dworkin’s criticism, if not compelling, at least relevant.’48

His contention is that a form of positive positivism may be devised that is capable of overcoming Dworkin’s objections. He begins from the suggestion that the rule of recognition can be framed so as to have one clause devoted to principles of morality. This is necessary because not all moral principles can be legally binding, for which some test or other mode to distinguish binding and non-binding moral principles must be identified. Coleman proposes a rule of

47ibid 5-6.

48ibid 8.

recognition stipulating that a rule is a legal rule if it possesses characteristic C, and a moral principle legally binding if it features characteristic C1.

The interesting thing about this rule of recognition is that ‘everything that Dworkin ascribes to positivism, other than the model of rules, survives.’49 (By ‘model of rules’ is meant here the thesis that that only standards possessing the right pedigree amounts to a law.) First, the rule of recognition in its semantic sense holds good, because the legality of a norm does not depend on whether it is a rule or a principle, but on whether it satisfies one or the other condition stated in the rule of recognition. The separability thesis also remains valid just so long as one conceivable norm in one conceivable system is validated as a law on satisfying a C clause rather than a C1 clause. Lastly, even Hart’s conjecture about judicial discretion in hard cases survives Dworkin’s challenge, because since only a determinate set of norms, both legal rules and moral principles, are accorded legal recognition, a case may well arise that is not covered by either a legal or moral standard, which will compel the judge to apply a non-legal standard in order to reach a decision.50

(9.4) Inclusive and Exclusive Positivism

The roots of the inclusive legal positivism thesis also lie in the philosophy of HLA Hart though, in common with several of the ideas discussed here, its development was undertaken by his students. WJ Waluchow is regarded as a leading proponent of this thesis, along with notables like Jules Coleman and Matthew Kramer. Other hand, Joseph Raz is known as a defender of exclusive positivism, as are Scott Shapiro and Andrei Marmor.

But what exactly are these theses? The central idea behind inclusive positivism is simple. It postulates that legal validity may depend on moral as well as formal considerations. Or to put it another way, the rule of recognition may feature moral criteria along with others. Several examples abound in the Indian Constitution. For example, after Maneka Gandhi v. Union of India it is well-settled that the right to life and personal liberty can be curtailed not by any procedure established by law, but only a procedure that is just, fair and reasonable. Hence when examining the validity of, say, a new preventive detention law, that part of the rule of recognition that is represented by Part III of the Constitution will take into account not only objectively determinable ‘social facts’ (such as whether it has been passed by both Lok Sabha and Rajya Sabha with sufficient numbers of members present and voting), but also moral criteria like whether it conforms to established standards of justness, fairness and reasonability. Indeed, some theorists have adopted an inclusivist position simply because they find it a more ‘natural position’.51 Waluchow, for example, describes the exclusive position as

49ibid 13.

50ibid.

51Danny Priel, ‘Farewell to the Exclusive–Inclusive Debate’ (2005) 25 Oxford Journal of Legal Studies 675, 679.

simply counter-intuitive: ‘It seems quite at odds with our ordinary understanding of a constitutional document like the Canadian Charter.’52

The exclusivist position is much more nuanced and complicated, and all the more so because it appears counter-intuitive, as we just discussed. Let us take Raz’s version. Before we start discussing it, it is essential that we familiarise ourselves at least briefly with his treatment of practical reasons. Practical reasons are nothing but reasons for doing or not doing something. For example, we may switch on a fan to get relief from hot weather. Likewise, when we do not need the fan we switch it off so as not to waste electricity. Now at times these reasons may clash. Suppose I feel like eating an ice-cream in hot weather even though I have little money to spare. Here the reason for spending money (namely the desire for ice-cream) clashes with reasons for not spending (that is, financial prudence), and ultimately whichever way I decide will depend on which reason I consider weightier. At times one or more such competing reasons may be moral in nature. An example is when I come across a red light when I am in a hurry. Considerations of civic sense and road safety dictate that I stop till the light changes. On the other hand, shortage of time may tempt me to jump the light. These reasons which compete with one another, and the weightier of which prevails over the others, is what Raz terms ‘first order reasons’. Some reasons, however, work in a different manner. The evening before an important examination, preparations will be the only think on my mind. In such cases, one reason for action (namely my exam performance) becomes so significant that it becomes ipso facto a reason not to act on other competing reasons, that is, a reason to exclude from contemplation all other practical reasons. If some friends try to tempt me into going out with them for dinner or a movie, I shall surely tell them to get lost! And why? Because my desire to do well in the next days exam is so strong as to be a reason not to do anything other than study. Such reasons, which act as reasons not to act on other reasons or exclude others from consideration, Raz terms ‘second-order’ reasons or ‘exclusionary’ reasons.

So how is this relevant to our discussion on positivism? The connection lies in this manner. According to Raz, laws are authoritative statements, that is, they claim authority unto themselves. Anything that claims authority must function as an exclusionary reason. Obeying or jumping a red light is not a matter merely of morality versus expediency. Let us not forget there is a legal consideration attached to the issue. And by rights, the mere fact that jumping a red light is illegal ought to exclude all other reasons from consideration, because it carries the authority of law. Now when a law incorporates morality qua morality, it does not replace the first order reason that already applies on us; it merely tells us to act on the first-order moral reason that was already imposed on us. This is manifestly inconsistent with the idea that law, in order to claim authority, has to provide exclusionary reasons for action.

52WJ Waluchow, Inclusive Legal Positivism (OUP 1994) 158-59.

According to Himma,53 Raz’s critique of inclusive positivism is based on three distinct theses. These include what he terms the Authority Thesis (i.e. that inclusive positivism is inconsistent with the nature of authority) and the Preemption Thesis (‘authority figures (or ought to figure) into practical deliberations by replacing the subject’s evaluation of the balance of reasons’, that is, that authority functions as a second-order or exclusionary reason).54 Additionally, Himma claims that Raz’s viewpoint also depends on a third thesis ‘that has gone largely unchallenged in the literature’: namely the Instantiation Thesis, or that ‘law cannot sincerely claim authority unless it is capable of instantiating authority.’55 In other words, it cannot be claimed that a particular body has authority unless it is capable of bearing authority in the first place.

(9.5) Conclusion

In this discussion, we encountered three new developments pertaining to positivism, all of which have directly or indirectly emanated from Hart’s contributions to jurisprudence. The first entails a distinction between substantive and methodological positivism. Substantive positivism is effectively the positivism we are familiar with, i.e. the separation of law and morals, so it involves little that is new to us. Hence little need exists for us to discuss it here. Methodological positivism involves the separation of morality from the study of law rather than the law itself. It presents to us certain new, unprecedented issues, which have spawned a considerable debate. Which is why it is expedient to address it in detail here.

In the light of the debate we examined earlier the question still remains, what can be said about the status of methodological positivism? Certainly in debates of this sort, an authoritatively correct answer is usually not possible. But we may at least recognise the following with some assurance. First, the distinction between substantive and methodological positivism appears to be insightful, to the extent that they entail separate undertakings and one does not follow from the other. Secondly, while Perry’s perceived inadequacies in Hart’s account of law can possibly sustain further investigation, his contention that conceptual analysis from the internal viewpoint must be undertaken either from a sceptical point of view or from a Dworkinian one appears debatable. This is because, as so many have pointed out, evaluation, even a moral evaluation, can be undertaken without endorsing some or the other moral position. Consequently, there is good reason to suggest that the idea of methodological positivism, that is to say engaging in a general, morally neutral, descriptive account of legal phenomena, may not necessarily be a futile quest. Moreover, this engagement will remain meaningful even if the substantive criteria of positivism are diluted to take into account

53KE Himma, ‘The Instantiation Thesis and Raz’s Critique of Inclusive Positivism’ (2001) 20 Law and Philosophy 61.

54ibid.

55ibid. 61-62.

norms of morality, such as what inclusive positivism, which we shall examine in detail later, contemplates.

Apart from this distinction, we also encountered the notion of negative and positive positivism. This was devised in response largely to Dworkin’s classic attack on positivism. Negative positivism involves ‘constraining’ the rule of recognition by the separability thesis, which carries the implication that all rules of recognition need not necessarily entail moral criteria. Positive positivism, on the other hand, entails the belief that no moral consideration can ever form a part of the rule of recognition; this position is conceptually similar to the exclusive positivism of Raz and Shapiro. Coleman then proposes a version of positive positivism, one where the rule of recognition uses criterion C to validate rules as legal, and criterion C1 to similarly validate moral norms as legally binding. As he claims, the advantage of this construct is that it satisfactorily deals with nearly all that Dworkin identifies as shortcomings of positivism.

Lastly, we explored the notion of inclusive and exclusive positivism. Conceptually inclusive positivism resembles Coleman’s negative positivism to a large extent, except that it is broader in ambit. It entails the belief that legal validity may depend on moral as well as formal considerations. Proponents of this theory find it attractive because it closely resembles the working of real-life constitutions. On the other hand, exclusive positivism explicitly rejects moral norms as criteria of legal validity. Raz’s argument in favour of exclusive positivism stems from his concept of the authority of law. This, to his mind, must provide to agents second-order or exclusionary reasons for compliance. And this requirement is frustrated when the law incorporates within it norms of morality qua morality.

These, in brief, are a sample of the kind of developments that have taken place within the framework of positivism as a direct consequence of Hart’s contributions. Certainly they are not exhaustive of such developments. Doubtless other theorists have also in their own ways taken off from Hart’s core philosophy and reached new conclusions. Considerations of space, however, compel us to limit ourselves to these three forms, arguably the more prominent among all others.

Learn More

1. JL Coleman, ‘Negative and Positive Positivism’ (1982) 11 Journal of Legal Studies 139.
2. JL Coleman, Markets, Morals, and the Law (OUP 1998).
3. J Dickson, Evaluation and Legal Theory (Hart Publishing 2001) 37.
4. Stephen Guest, ‘Two Strands in Hart’s Concept of Law: A Comment on the Postscript to Hart’s The Concept of Law’ in Stephen Guest (ed) Positivism Today (Dartmouth Publishers 1996) 29.
5. HLA Hart, The Concept of Law (2nd edn, OUP 1994).
6. KE Himma, ‘The Instantiation Thesis and Raz’s Critique of Inclusive Positivism’ (2001) 20 Law and Philosophy 61.
7. B Leiter, ‘Beyond the Hart/Dworkin Debate: The Methodology Problem in Jurisprudence’ (2003) 48 American Journal of Jurisprudence 17.
8. L Moore, ‘Description and Analysis in the Concept of Law: A Response To Stephen Perry’ (2002) 8 Legal Theory 91.
9. SR Perry, ‘The Varieties of Legal Positivism’ (1996) 9 Canadian Journal of Law and Jurisprudence 361.
10. WJ Waluchow, Inclusive Legal Positivism (OUP 1994).