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Fuzzy Law: A Theory of Quasi-Legal Systems

  • Oren Perez


Our lives are permeated by various forms of legality, produced by multiple bodies - both statist and non-statist. The pervasive presence of non-statist, soft law schemes in the contemporary society poses a challenge for legal theory: how to conceptualize legal-like structures that evolve outside the boundaries of the state and are able nonetheless to exert significant normative power? Understanding this phenomenon requires, I argue, a new model of law that will not be bounded by the binary (either/or) structure of traditional jurisprudence and sociology of law. I respond to this challenge by developing a degree-theoretic model of legal-normativity which I term "fuzzy law". This model offers a new conceptual vocabulary for thinking about soft law as a social phenomenon. The model draws on three main theoretical sources: the theory of complementary pairs, fuzzy-set theory, and defeasible reasoning. I examine the jurisprudential and sociological implications of the fuzzy law model through a discussion of the dialectics of reasoning with fuzzy rules and an exploration of the coordination dynamics of quasi-legal systems.



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1. Lars Chr Blichner & Anders Molander, ‘Mapping Juridification’ (2008) 14 Eur LJ 36.

2. See, e.g., the Global Reporting Initiative (GRI), Sustainability Reporting Guidelines G3.1 (2011), online:; International Standards Organization (ISO), ISO 14001: Environmental Management Systems (1996) [ISO 14001]; Forest Stewardship Council, Certification Scheme, online:

3. D Zaring, ‘Best Practices’ (2006) 81 NYUL Rev 294.

4. See, e.g., Walmart, Standards for Suppliers (January 2012), online: For further examples see McKague, Kevin & Cragg, Wesley, Compendium of Ethics Codes and Instruments of Corporate Responsibility (Toronto: York University, 2003).

5. See, e.g., American College of Emergency Physicians, Principles of Ethics for Emergency Physicians, online: ACEP; Australian Medical Council, Good Medical Practice: A Code of Conduct for Doctors in Australia, online:

6. See, e.g., Indiana University Bloomington, Code of Academic Ethics, online:∼vpfaa/academicguide/index.php/Policy_I-1.

7. The conference took place on 9-10 January 2014 and was hosted by IBEI (Institut Barcelona d’Estudis Internacionals) and ESADEgeo-Center for Global Economy and Geopolitics.

8. See, e.g., Thomas W Merrill, ‘Trespass, Nuisance, and the Costs of Determining Property Rights’ (1985) 14 J Legal Stud 13; Pascal Courty, ‘Some economics of ticket resale’ (2003) 17 J Econ Perspectives 85 and Solomon Philip Elias, The Law of Theater Tickets (San Francisco: WA Hiester, 1905), online:

9. Some cities have such codes. The codes are usually promulgated by the city authority and tend to regulate only the behavior of the musicians. See, e.g., Vancouver rules on busking, online: City of Vancouver; Draft Plan for St. Augustine Buskers, online: St. Augustine Government Further, see Paul Simpson, ‘Street Performance and the City: Public Space, Sociality, and Intervening in the Everyday’ (2011) 14 Space and Culture 415 at 423-26; Andrew Blankstein & Abby Sewell, ‘Judge blocks Venice boardwalk permit system’ (27 Oct 2010), online: Los Angeles Times

10. These codes tend to regulate only the performers’ behavior.

11. Oren Perez, ‘Purity Lost: the Paradoxical Face of the New Transnational Legal Body’ (2007) 33 Brook Int’l LJ 1; Sally Engle Merry, ‘Global Legal Pluralism and the Temporality of Soft Law’ (2014) 46 J Legal Pluralism 108.

12. See, e.g., Max Black, ‘Vagueness’ (1937) 4 Philosophy of Science 427; Roy Sorensen, ‘Vagueness’, The Stanford Encyclopedia of Philosophy (Winter 2013), Edward N Zalta, ed, online:

13. See Scott Kelso, JA & Engstrom, David A, The Complementary Nature (Boston: MIT Press, 2006); Dubois, Didier et al, ‘Fuzzy Sets: History and Basic Notions’ in Dubois, Didier & Prade, Henri, eds, Fundamentals of Fuzzy Sets (2000) 21; Jaap Hage, ‘A Theory of Legal Reasoning and a Logic to Match’ (1996) 4 AI & L 199, s 16.

14. See, e.g., Andrei Marmor, ‘Varieties of Vagueness in the Law’, USC Legal Studies Research Paper No. 12-8, online: SSRN (2012); Timothy Endicott, Vagueness in Law (Oxford: Oxford University Press, 2000).

15. Not to be confused with John Austin the jurist who worked in the 19th century (1790-1859).

16. Austin, JL, How to do Things with Words (Oxford: Oxford University Press, 1955, 1975) at 3, 5. Examples of performatives are the acts of marrying, betting, bequeathing, christening at 19, 33.

17. Ibid at 14-15.

18. One of the prominent examples Austin gives for infelicitous execution is when a conventional procedure (e.g., marrying) is performed either incorrectly or incompletely (conditions B.1 and B.2 to his classificatory scheme): ibid at 15.

19. Ibid at 16. Austin does not deny that infelicitous performatives can have real implications in the world but he insists that they will remain void (talking about the act of marriage): “Two final words about being void or without effect. This does not mean, of course, to say that we won’t have done anything: lots of things will have been done—we shall most interestingly have committed the act of bigamy—but we shall not have done the purported act, viz., marrying. Because despite the name, you do not when bigamous marry twice. (In short, the algebra of marriage is BOOLEAN.) Further, ‘without effect’ does not here mean ‘without consequences, results, effects’”: ibid at 17.

20. Ibid at 34, 23.

21. Ibid at 17.

22. Austin, supra note 16 at 94-103. See also, John R Searle, ‘Austin on locutionary and illocutionary acts’ (1968) Philosophical Rev 405 at 405-06.

23. Austin, ibid at 135-37, 147. A similar binary conceptualization can also be found in the work of John Searle on speech acts. See Searle, John R, Speech Act Theory: An Essay in the Philosophy of Language (Cambridge: Cambridge University Press, 1969), Searle, John R & Vanderveken, Daniel, Foundations of Illocutionary Logic (Cambridge: Cambridge University Press, 1985) at 1-26, and John R Searle, ‘A classification of illocutionary acts’ (1976) 5 Language in Society 1 at 14.

24. Martinich, Aloysius P, The Philosophy of Language (Oxford: Oxford University Press, 1990) at 22–26.

25. S Shapiro, ‘What is the rule of recognition (and does it exist)?’ (2009) Yale Law School, Public Law Working Paper No. 184, online: SSRN at 6, 11 [Shapiro (2009)]; Shapiro, Scott J, Legality (Oxford: Oxford University Press, 2012) at 85 [Shapiro (2012)]; J Dickson, ‘Is the Rule of Recognition Really a Conventional Rule?’ (2007) 27 Oxford J Legal Stud 373 at 377.

26. See also John M Rogers & Robert E Molzon, ‘Some Lessons about the Law from Self-Referential Problems in Mathematics’ (1992) 90 Mich L Rev 992 at 998.

27. This formula would have the following structure: SL(x) {x | x has properties (A1, …, Am)}, where x is a normative statement; Shapiro (2009), supra note 25 at 5.

28. The rule of recognition differs from the law’s other rules in that it “validates but is not itself validated”; it is a reflection of social convention. Shapiro (2012), supra note 25 at 84.

29. Joseph Raz, ‘The Problem of Authority: Revisiting the Service Conception’ (2006) 90 Minn L Rev 1003 at 1022.

30. Raz, Joseph, Between Authority and Norms: On the Theory of Law and Practical Reason (Oxford: Oxford University Press, 2009) 7. Raz emphasizes that the considerations which establish that a rule is binding do not turn on the desirability of the acts for which the rule is a reason. The insightfulness and subtlety of a novel Raz argues are reasons for reading it because they show why reading it is good. But the considerations which show why a rule is binding, i.e., why it is a reason for complying with its prescription, turn on the desirability of having the affairs of the community being ordered by a legal institution; Joseph Raz, ‘Reasoning with Rules’ (2001) 54 Curr Legal Probs 1.

31. Philip Selznick, ‘Sociology and Natural Law’ (1961) 6 Natural Law Forum 84 at 99 [my emphasis].

32. Searle, supra note 23 at 123. William Edmundson has described this feature of legal reasons as their ‘because I said so’ quality; William Edmundson, ‘Because I Said So’ (27 October 2012). Georgia State University College of Law, Legal Studies Research Paper, online: SSRN

33. Raz (2006), supra note 29 at 1022. A protected reason to ϕ then is a “first order reason to ϕ and an exclusionary reason not to fail to ϕ for a certain range of excluded reasons”. Joseph Raz, ‘On Respect, Authority, and Neutrality: A Response’ (2010) 120 Ethics 279 at 298.

34. SJ: {x | x is a jazz piece}.

35. G Tzanetakis & P Cook, ‘Musical genre classification of audio signals’ (2002) 10 Speech and Audio Processing, IEEE Transactions 293 at 300.

36. This view is consistent with degree-theoretic approaches to truth. See Cook, Roy T, ‘Vagueness and Meaning’ in Ronzitti, G, ed, Vagueness: A Guide (Berlin: Springer, 2011) at 83, 86.

37. See, e.g., Jacob E Gersen & Eric A Posner, ‘Soft Law’ (2010) 61 Stan L Rev at 573, 575 (noting the fact that congressional soft law, despite of its lack of formal legal status, can ultimately have a real effect) and Andrew T Guzman & Timothy L Meyer, ‘International Soft Law (2010) 2 J Legal Analysis 171 at 179-83 (noting the increasing use of soft law instruments at the transnational domain).

38. Oren Perez, Yair Amichai-Hamburger & Tammy Shterental, ‘The Dynamic of Corporate Self-Regulation: ISO 14001, Environmental Commitment, and Organizational Citizenship Behavior’ (2009) 43 Law & Soc’y Rev 593 and Teubner, Gunther, Constitutional Fragments: Societal Constitutionalism and Globalization (Oxford: Oxford University Press, 2012).

39. And “if something is not legally binding, it cannot be softly legally binding either”; Jan Klabbers, ‘Redundancy of Soft Law’ (1996) 65 Nordic J Int’l L at 167, 181; Jan Klabbers, Reflections on Soft International Law in a Privatized World, (CITY: PUB, 2006) at 4, online:; see also Prosper Weil, ‘Towards Relative Normativity in International Law?’ (1983) 77 Am J Int’l L 413 at 415, 417-18.

40. Kenneth W Abbott et al, ‘The Concept of Legalization’ (2000) 54 International Organization 401.

41. The term ‘crisp’ is borrowed from the literature on fuzzy sets in which it is used to distinguish between crisp and fuzzy sets; see: Lotfi A Zadeh, ‘Toward a Theory of Fuzzy Information Granulation and its Centrality in Human Reasoning and Fuzzy Logic’ (1997) 90 Fuzzy Sets and Systems 111 at 113.

42. Here is a common statement of this view “A systematic reconstruction of the law needs to identify set of properties that a norm must exhibit to be part of a certain legal system…. These properties are often called ‘criteria of validity’” Pablo E Navarro & Jorge L Rodriguez, Deontic Logic and Legal Systems (Cambridge: Cambridge University Press, 2014) at 118.

43. The either/or frame represents two different frames because it can be interpreted as valorizing one side of the distinction (e.g., legal/illegal, good/bad) which brings the different possible interpretations of a complementary pair to four; Kelso & Engstrom, supra note 13 at 50.

44. See Kelso & Engstrom, ibid at 51.

45. David A Engstrøm & JA Scott Kelso, ‘Coordination Dynamics of the Complementary Nature’ (2008) 30 Gestalt Theory 121 at 123.

46. Kelso & Engstrom, supra note 13 and JA Kelso, ‘The Complementary Nature of Coordination Dynamics: Toward a Science of the In-Between Uncertainty and Surprise in Complex Systems’ in R McDaniel & D Driebe, eds, Uncertainty and Surprise in Complex Systems: Questions on Working with the Unexpected (Berlin: Springer, 2005) 77.

47. Kelso & Engstrom, supra note 13 at 73.

48. The coordination dynamics associated with complementary pairs is informational in nature, which means that information is actively used to coordinate things. Engstrøm & Kelso, supra note 45 at 125.

49. Kelso & Engstrom use their framework to the study the brain and their detailed model cannot therefore be applied as such to the legal context.

50. See Lotfi A Zadeh, ‘The Birth and Evolution of Fuzzy Logic’ (1990) 17 International Journal of General Systems 95.

51. See Lotfi A Zadeh, ‘Is There a Need for Fuzzy Logic?’ (2008) 178 Information Sciences 2751 at 2753.

52. For a similar application in the medical field, see, e.g., Rudolf Seising, ‘From Vagueness in Medical Thought to the Foundations of Fuzzy Reasoning in Medical Diagnosis’ (2006) 38 Artificial Intelligence in Medicine 237.

53. Thus, for example, police officers commonly draw on the following generalization in making judgments about guilt: “fleeing from the crime scene indicates consciousness of guilt”. However, this general statement can be defeated if in a particular instance the police officer finds out that the suspect was an illegal immigrant who wanted to avoid the police fearing deportation. See Prakken, H & Sartor, G (2009). A logical analysis of burdens of proof. In Kaptein, H, Prakken, H & Verheij, B, eds, Legal Evidence and Proof: Statistics, Stories, Logic 223 at 237 (Aldershot: Ashgate, 2009).

54. Prakken & Sartor, ibid at 229. See also Robert Koons, ‘Defeasible Reasoning’, The Stanford Encyclopedia of Philosophy (Spring 2014), Edward N Zalta, ed, online:

55. See Jeremy Waldron, ‘Vagueness and the Guidance of Action’ NYU School of Law, Public Law Research Paper No. 10-81, online: SSRN (2010). See also Marmor, supra note 14 and Endicott, supra note 14.

56. See HLA Hart, ‘Positivism and the Separation of Law and Morals’ (1958) 71 Harv L Rev 593 at 606-15. This inexactness reflects, first, the fact that the linguistic conventions that determine the meaning of words are not fully determinative. Second, law creates further semantic puzzles by superimposing its (potentially conflicting and inexact) principles on general linguistic conventions. See Frederick Schauer, ‘A Critical Guide to Vehicles in the Park’ (2008) 83 NYUL Rev 1109. It is possible to distinguish in this context between transparently vague concepts, such as sorites predicates and extravagantly vague concepts such as the criminal offence of neglecting a child. Extravagantly vague concepts are more complex because “they designate a multidimensional evaluation with incommensurable constitutive elements”; see Marmor, supra note 14 at 4. Due to their underlying multidimensionality extravagantly vague concepts are much more resistant to precification.

57. Marmor, supra note 14.

58. This type of predicates produces the famous sorites paradox. Dominic Hyde, ‘Sorites Paradox’, The Stanford Encyclopedia of Philosophy (Winter 2011 Edition), Edward N Zalta, ed, online:

59. Other types of linguistic inexactness, which I will not discuss here, are ambiguity (which refers to terms that have multiple meanings, e.g., “bank,” “cut,” “park”) and generality (which refers to terms that can be applied to a variety of situations and whose meaning may vary with context, e.g., “car,” “property”). See JA Goguen, “The Logic of Inexact Concepts” (1969) 19 Synthese 325 at 345.

60. Michael Spence & Timothy Endicott, ‘Vagueness in the Scope of Copyright’ (2005) 121 Law Q Rev 657.

61. Marmor, supra note 14 at 10. Leo Katz notes similarly, that “however unsure we are whether a defendant has acted in good faith or bad, reasonably or negligently, the law will eventually classify his actions in one of those two bins, good or bad faith, reasonable or negligent. It won’t split the difference”; Katz, Leo, Why the Law Is So Perverse (Chicago: University of Chicago Press, 2011) at 144. See further Twining, William & Miers, David, How to Do Things with Rules: a Primer of Interpretation, 5th ed (Cambridge: Cambridge University Press, 2010) at 169-71.

62. (June 24, 2010) 130 S Ct 2896.

63. Ibid at 2907.

64. Ibid at 2927.

65. Ibid at 2929.

66. Ibid at 2931. Drawing on this revised interpretation of §1346 the Court has affirmed the Fifth Circuit’s ruling on Skilling’s fair-trial argument, vacated its ruling on his conspiracy conviction, and remand the case for proceedings consistent with this opinion. Ibid at 2935. For further discussion of this case see: Justin Weitz, ‘The Devil is in the Details: 18 U.S.C. § 666 after Skilling v. United States’ (2011) 14 NYUJ Legis & Pub Pol’y 805.

67. The capacity of law to resolve meaning disputes in concrete cases does not prevent future meaning conflicts because of the indeterminate nature of analogical reasoning. As Cass Sunstein notes: “The method of analogy is based on the question: Is case A relevantly similar to case B, or not? … To answer such questions, one needs a theory of relevant similarities and differences. By itself, analogical reasoning supplies no such theory. It is thus dependent on an apparatus that it is unable to produce”; Cass R Sunstein, ‘On Analogical Reasoning’ (1993) 106 Harv L Rev 741 at 773-74.

68. This confusion is particularly apparent in the work of Abbott et al (supra note 40) which brings together obligation, precision, and delegation as three dimensions of legality.

69. Andrei Marmor similarly distinguishes between semantic and conversational vagueness. In his opinion, an expression can be vague (or precise) with respect to a specific conversation independently of any semantic vagueness. This form of vagueness can be dissipated only after exposing the particulars of the context. Marmor, supra note 14 at 7.

70. The deontic syntax is based on three basic forms: a prescriptive form (ought to, OB), a permissive form (may, PE), and a prohibitive form (impermissible that, IM). The obligatory form is commonly taken as basic and can be used to derive the other forms: PEp ↔ ∼OB∼p; IMp ↔ OB∼p. See McNamara, Paul, ‘Deontic Logic’The Stanford Encyclopedia of Philosophy (Summer 2010) Zalta, Edward N, ed, online: (2010). For a less formal discussion of the logic of rules, see Twining & Miers, supra note 61. The law includes additional types of norms, such as competence norms and determinative norms. Eugenio Bulygin, ‘On Norms of Competence’ (1992) 11 Law & Phil 201.

71. Institutionally-generated vagueness has both epistemic and metaphysical features. It is epistemic because it can be explained, in part, by our not knowing enough about the notion of legal bindingness and by the difficulty (as will be explained below) of articulating the social convention by which people relate certain institutional facts to levels of bindingness. But it also has a metaphysical feature because there is something intrinsically contingent about the idea of legal bindingness, as I elaborate below. For the distinction between epistemic and metaphysical vagueness see: Trenton Merricks, ‘Varieties of Vagueness’ (2001) 62 Philosophy and Phenomenological Research 145.

72. This point is also emphasized by Searle who notes that the force of declarations depends on extra-linguistic institutions and not just on linguistic conventions (although he makes this argument in the context of a crisp framework), see John Searle, Making the Social World: The Structure of Human Civilization (Oxford: Oxford University Press, 2010) at 111-14.

73. That is, observers that are not directly involved in the social interaction influenced by the rule.

74. See further on this point: Searle (2010), supra note 72 at 128-29.

75. While a judge in a moot court trial has some normative influence within that artificial process (e.g., she can declare one team as the winner), she has no influence beyond this process.

76. Charles Goodwin & John Heritage, ‘Conversation analysis’ (1990) 19 Annual Review of Anthropology 283 at 286 and Alfred Schütz, Collected Papers: The Problem of Social Reality Volume I § 1 (Berlin: Springer, 1982) at 11-12. The fact that a particular (fuzzy) rule may be disregarded in a particular interaction does not change its (fuzzy) normative value, although it may signal a change in collective expectations.

77. I will use the terms quasi-legal system and fuzzy legal system interchangeably to designate soft legal schemes.

78. The question of membership would be resolved through a conventional, sourced-based principle of legality, that is, whether the norm was created in accordance with a power-conferring norm that is part of the fuzzy system; See Navarro & Rodriguez,supra note 42 at 144.

79. As John Horty notes “some of the most important things we reason about, and reason about defeasibly, are the priorities among the very defaults that guide our defeasible reasoning”; JF Horty, ‘Reasons as Defaults’ (2007) 7 Philosophers’ Imprint 10. John Horty has developed a formal model of this process of meta-order reasoning: see Horty, JF, Reasons as Defaults (Oxford: Oxford University Press, 2012) 111. I doubt, however, whether Horty’s formal model can capture the implicit dynamic of fuzzy legal systems.

80. R Conte et al, ‘Manifesto of Computational Social Science’ (2012) 214 The European Physical Journal Special Topics 325 at 328; S Buckingham Shum et al, ‘Towards a Global Participatory Platform’ (2012) 214 The European Physical Journal Special Topics 109 at 142; F Giannotti et al, ‘A Planetary Nervous System for Social Mining and Collective Awareness’ (2012) 214 The European Physical Journal Special Topics 49 at 62.

81. Law authorizes the institutions (‘courts’) that resolve disputes about the meaning and application of rules. See Joseph Raz, ‘Sorensen: Vagueness has No Function in Law’ (2002) 7 Legal Theory 417.

82. Engstrøm & Kelso, supra note 45.

83. IB Turksen, ‘Measurement of Membership Functions and their Acquisition’ (1991) 40 Fuzzy Sets and Systems 5 at 8.

84. In other words, fA(x) represents the degree with which the use of the linguistic term A (tall) is compatible with the attribute V (height) of an element x ∈ X (a particular Tel-Aviv resident). Lotfi A Zadeh, ‘Fuzzy Sets’ (1965) 8 Information and Control 338.

85. This aggregation function would be composed in effect from multiple membership functions, one for each of the designated attributes of perfect legal system. The aggregation could be based either on arithmetic mean or on some weighted average (which could give more weight to some attribute, e.g., the level of independence of the court system). See Reid, Andrew & Frank, Richard, ‘Celerity in the Courts: The Application of Fuzzy Logic to Model Case Complexity of Criminal Justice Systems’ in Dabbaghian, Vahid & Mago, Vijay Kumar, eds, Theories and Simulations of Complex Social Systems (Berlin: Springer, 2014) 79 at 84–86.

86. For different attempts to define this matrix see, e.g., LP Feld & S Voigt, ‘Economic growth and judicial independence: cross-country evidence using a new set of indicators’ (2003) 19 European Journal of Political Economy 497; Abbott et al, supra note 40; Joost Pauwelyn, et al, Informal international lawmaking (Oxford: Oxford University Press. 2012); Martha Finnemore & Stephen J Toope, ‘Alternatives to “Legalization”: Richer Views of Law and Politics’ (2001) 55 International Organization 743; Sylvia I Karlsson-Vinkhuyzen & Antto Vihma, ‘Comparing the legitimacy and effectiveness of global hard and soft law: An analytical framework’ (2009) 3 Regulation & Governance 400 and James Melton et al, ‘On the interpretability of law: Lessons from the decoding of national constitutions’ (2013) 43 British Journal of Political Science 399 at 414. Feld and Voigt, for example, decompose the attribute of judicial independence into 12 de jure sub-variables and 8 de facto (sociological) variables, Feld & Voigt, ibid at 501-04.

87. Ibid at 501-03. This interpretation assumes that in the legal context typicality (goodness of example) and vagueness (gradedness of membership) can be used as interchangeable concepts. For such an argument see James A Hampton, ‘Typicality, Graded Membership, and Vagueness’ (2007) 31 Cognitive Science: A Multidisciplinary Journal 355 at 356 and Michael T Hannan, ‘Partiality of Memberships in Categories and Audiences’ (2010) 36 Annual Review of Sociology 159 at 164. One potential difficulty in this argument concerns the fact that soft legal structures may develop alternative forms of reflexivity which do not depend on central judicial institutions of the type found in traditional legal systems.

88. The following quote from Rosanne Keefe is instructive: “[T]he degree theorist’s assignments impose precision in a form that is just as unacceptable as a classical true/false assignment. In so far as a degree theory avoids determinacy over whether a is F, the objection here is that it does so by enforcing determinacy over the degree to which a is F… why should we suppose that propositions relate to the facts of the world in a neat infinite-valued way any more than in ‘a neat two valued way’?”.

89. For a more general response to Keefe’s argument see Nicholas Smith, Vagueness and Degrees of Truth (Oxford: Oxford University Press, 2008) and Nicholas Smith, ‘Fuzzy Logic and Higher-Order Vagueness’ in Petr Cintula, et al, eds, Understanding Vagueness: Logical, Philosophical and Linguistic Perspectives (College Publications, 2011) at 1-19.

90. JA Goguen, ‘The Logic of Inexact Concepts’ (1969) 19 Synthese 325 at 331-32 [emphasis in the original]; see also Smith (2011), ibid at 4.

91. Ibid.

92. For a description of musical notation schemes, see George Langley, ‘Musical Expression from the Performer’s Point of View’ (1911) 38 Proceedings of the Musical Association 1. The use of linguistic terminology rather than numerals to designate grades of legality is also consistent with the attempt to utilize fuzzy logic to enable word-based computation. Lotfi A Zadeh, ‘From Computing with Numbers to Computing with Words: From Manipulation of Measurements to Manipulation of Perceptions’ (2001) 929 Ann NY Acad Sci 221.

93. Smith (2011), supra note 89 at 8. Further support for the pluralistic argument can be found in the literature on the elicitation of fuzzy membership functions. See, e.g., Charles C Ragin, Fuzzy-Set Social Science (Chicago: University of Chicago Press, 2000) 165; T Bilgic & IB Turksen, ‘Elicitation of Membership Functions: How far can theory take us?’ (1997) Proceedings of the Sixth IEEE International Conference on Fuzzy Systems.

94. The argument for viewing the fuzzy theory of vagueness as a model is advanced by Roy T Cook, ‘Vagueness and Mathematical Precision’ (2002) 111 Mind 225 at 235-36; see further, Smith (2011), ibid at 5.

95. Oren Perez, ‘Regulation as the art of intuitive judgment: a critique of the economic approach to environmental regulation’ (2008) 4 Int’l J Law in Context 291 at 298.

96. See, e.g., ‘Civil Society Platform on Access to Culture: Policy Guidelines’ (Structured dialogue EU—Cultural Sector, 2009) at 7, online:

97. T Keren-Paz, ‘Egalitarianism as Justification: Why and How Should Egalitarian Considerations Reshape the Standard of Care in Negligence Law?’ (2003) 4 Theor Inq Law. The distinction between moral and legal reasons has a long history. In Donoghue v Stevenson, Lord Atkin noted that “acts or omissions which any moral code would censure cannot in a practical world be treated so as to give a right to every person injured by them to demand relief. In this way rules of law arise which limit the range of complainants and the extent of their remedy”: [1932] AC at 580, [1932] All ER Rep at 11. See also Home Office v Dorset Yacht Co Ltd, [1970] 2 All ER 294 at 307. John Kleinig makes a similar distinction between institutionalized and non-institutionalized desert claims; John Kleinig, ‘The Concept of Desert’ (1971) 8 Am Phil Q 71 at 71, 74.

98. Prakken & Sartor, supra note 53 at 232.

99. For an attempt to analyse this cognitive process, see Searle, supra note 72 at 123-32 and Giovanni Sartor, ‘Defeasibility in Legal Reasoning’ in J Ferrer Beltrán & GB Ratti, eds, The Logic of Legal Requirements: Essays on Defeasibility, Oxford University Press, Oxford, EUI Law Working Paper No. 2009/02 1, n 3.

100. See Larry Alexander, ‘Scalar Properties, Binary Judgments’ (2008) 25 Journal of Applied Philosophy 85, 85 [emphasis added] and Larry Alexander, ‘Deontology at the Threshold’ (2000) 37 San Diego L Rev 893. This idea is also explored in Prakken and Sartor, supra note 53 at 232.

101. Note that under this model the substantive reasons that were used (or could have been used) to support P when it was originally enacted continue to be irrelevant to the resolution of the conflict.

102. See section B above.

103. E Millgram & P Thagard, ‘Deliberative Coherence’ (1996) 108 Synthese 63; P Thagard & K Verbeurgt, ‘Coherence as Constraint Satisfaction’ (1998) 22 Cognitive Science 1.

104. Dan Simon & Keith J Holyoak, ‘Structural Dynamics of Cognition: From Consistency Theories to Constraint Satisfaction’ (2002) 6 Personality and Social Psychology Review 283 at 284.

105. DAN Sperber et al, ‘Epistemic Vigilance’ (2010) 25 Mind & Language 359 at 376-77.

106. Perez, supra note 38.

107. In some cases state law can provide external support to CSR norms, changing their degree of bindingness. Veronica Besmer describes the attempt to enforce Nike CSR commitments, drawing on California unfair competition law, alleging that Nike committed negligent or intentional misrepresentation by providing misleading replies to allegations about labour exploitation in its sub-contractors’ facilities. These allegations, which eventually were proven as true, have been inconsistent with Nike’s self-prescribed commitments on this issue (codified in a memorandum of understanding signed with its sub-contractors in 1992); Veronica Besmer, ‘The Legal Character of Private Codes of Conduct: More than Just a Pseudo-Formal Gloss on Corporate Social Responsibility’ (2006) 2 Hastings Bus LJ (2006) 279 at 296-97.

108. Studies of CSR Codes have demonstrated the capacity of such codes to develop an autonomous dynamic that takes life of its own. Perez et al, supra note 38 at 617; Olivier Boiral, ‘Managing with ISO Systems: Lessons from Practice’ (2011) 44 Long Range Planning 197 at 212.

109. See, e.g., Paul Schiff Berman, Global Legal Pluralism: A Jurisprudence of Law Beyond Borders (Cambridge: Cambridge University Press 2012) and Oren Perez, ‘Private Environmental Governance as Ensemble Regulation: A Critical Exploration of Sustainability Indexes and the New Ensemble Politics’ (2011) 12 Theor Inq Law 543.

110. Indeed, even a developed institutional-legal structure does not necessitate the emergence of autonomous legal system. The former Soviet Union is a case in point. In that case the legal system constituted only a façade of legality, which was in realty completely controlled by the political party and its regime of power and fear. This point was nicely captured by Tom Rob Smith in his description of Lubyanka, the headquarters of the KGB: “An invisible borderline existed around the building … Crossing that line meant that you were either staff or condemned. There was no chance you could be found innocent inside these walls. It was an assembly line of guilt”. Tom Rob Smith, Child 44 (New York: Grand Central Publishing, 2008) at 79-80. See further on the KGB and its regime of terror, JM Waller, ‘Russia: Death and Resurrection of the KGB’ (2004) 12 Demokratizatsiya-Washington 333.

111. Niklas Luhmann’s distinction between normative and cognitive expectations is critical to this point. Normativity, Luhmann argues, means that certain expectations can be maintained even in the face of disappointment Niklas Luhmann, ‘Operational Closure and Structural Coupling: the Differentiation of the Legal System’ (1992) 13 Cardozo L Rev 1419 at 1426. See also Gunther Teubner, ‘The Two Faces of Janus: Rethinking Legal Pluralism’ (1992) 13 Cardozo L Rev 1443 at 1449-50.

112. For a detailed study of the emergence of such self-enforcing dynamic in the context of ISO 14001 environmental management system, see Perez et al, supra note 38.

113. Note that this process does not depend (at least not completely) on the capacity of fuzzy norms to change behavior.

114. Uslaner, Eric M, The Moral Foundations of Trust (Cambridge: Cambridge University Press, 2002) at 1.

115. J Giles ‘Internet encyclopedias go head to head’ (2005) 438 Nature 900; D Karpf ‘Open Source Political Community Development: A Five-Stage Adoption Process’ (2011) 8 Journal of Information Technology & Politics 323 at 329.

116. Some scholars use the term ‘Healthcare Ethics Committees’.

117. Royal College of Physicians, ‘Ethics in practice—Background and recommendations for enhanced support: A report of the working party on clinical ethics’ (London: Royal College of Physicians, 2005) [Royal College of Physicians].

118. Gordon DuVal et al, ‘A National Survey of U.S. Internists’ Experiences with Ethical Dilemmas and Ethics Consultation’ (2004) 19 Journal of General Internal Medicine 251 and Royal-College-of-Physicians, ibid.

119. Royal College of Physicians, supra note 117.

120. Thaddeus Mason Pope, ‘Multi-institutional healthcare ethics committees: the procedurally fair internal dispute resolution mechanism’ (2008) 31 Campbell L Rev 257 at 257 and Anita J Tarzian & ASBH Core Competencies Update Task Force, ‘Health care ethics consultation: An update on core competencies and emerging standards from the American Society for Bioethics and Humanities’ Core Competencies Update Task Force (2013) 13 American Journal of Bioethics 3 at 3.

121. G McGee et al, ‘A national study of ethics committees’ (2001) 1 American Journal of Bioethics 60; AM Slowther et al, ‘Development of clinical ethics services in the UK: a national survey’ (2012) 38 Journal of Medical Ethics 210; Duval et al, supra note 118.

122. SAM McLean, ‘Clinical Ethics Committees: a due process wasteland?’ (2008) 3 Clinical Ethics 99 at 101.

123. V Larcher et al, ‘Core Competencies for Clinical Ethics Committees’ (2010) 10 Clinical Medicine, Journal of the Royal College of Physicians 30 at 32; see also Tarzian & ASBH Core Competencies Update Task Force, supra note 120 at 8.

124. See Slowther, supra note 121 at 213 (noting the low referral rate in the context of UK CECs); RF Wilson, ‘Rethinking the shield of immunity: should ethics committees be accountable for their mistakes?’ (2002) 14 HEC Forum 172 (arguing that CECs should function as adjuncts to the courts, providing case consultation reviewable by the judiciary; in his opinion, the courts should have final authority in patient care decisions).

125. Pope, supra note 120 at 316.

126. Tarzian & ASBH Core Competencies Update Task Force, supra note 120 at 6-8.

127. See Perez, supra note 109 and Roughan, Nicole, Authorities: Conflict, Cooperation and Transnational Legal Theory-Introduction (Oxford: Oxford University Press, 2013).

128. Matthew Potoski & Aseem Prakash, ‘Covenants with Weak Swords: ISO 14001 and Facilities’ Environmental Performance’ (2005) 24 Journal of Policy Analysis and Management 745; Richard Perkins & Eric Neumayer, ‘Geographic Variations in the Early Diffusion of Corporate Voluntary Standards: Comparing ISO14001 and the Global Compact’ (2010) 42 Environment and Planning A 347; D Berliner & A Prakash, ‘Signaling Environmental Stewardship in the Shadow of Weak Governance: The Global Diffusion of ISO 14001’ (2013) 47 Law & Soc’y Rev 345.

129. See, e.g., the work in Boiral, supra note 108 and Perez at al, supra note 38.

130. See Yuval Feldman & Oren Perez, ‘Motivating Environmental Action in a Pluralistic Regulatory Environment: An Experimental Study of Framing, Crowding Out, and Institutional Effects in the Context of Recycling Policies’ (2012) 46 Law & Society Review 405. In this paper one of the questions we studied was to what extent the source of a legal prohibition—we distinguished between the state and two organizational settings: firm and academic institution—influences subjects’ attitudes toward the act of recycling. See ibid at 421, 429-31.

I would like to thank Patrick Glenn, Michael Helfand, Gabriel Lanyi, Tim Meyer, David Schiff, and Gunther Teubner for helpful conversations on the ideas articulated in this article. The paper was presented at: the HiiL/NIAS Workshop on Multi Valued Law and Multivalent Logic, 17-18 June 2011; at a research seminar at the Centre de recherche en droit public (CRDP), Faculty of Law, Université de Montréal, 14 September 2011 at a faculty seminar at the Faculty of Law, Bar Ilan University, 9 April 2013; and at “The ‘Soft’ and the ‘Fuzzy’ in Public and International Law” conference at the Hebrew University of Jerusalem, 17-18 February 2015. I would like to thank those who commented at these occasions. Thanks also to CJLJ editorial team for helpful comments.


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Fuzzy Law: A Theory of Quasi-Legal Systems

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