1 See J. d’Aspremont, Formalism and International Law: A Theory of the Ascertainment of Sources of Legal Rules (2011); J. von Bernstoff, The Public International Law Theory of Hans Kelsen: Believing in Universal Law (2010).

2 Ronald Dworkin's normative, interpretive theory of law, for example, is entirely internal from the ‘participant's point of view’, and in particular ‘from the judge's viewpoint’. R. Dworkin, Law's Empire (1986), 14.

3 See, e.g., J. Salmond, Jurisprudence (1924), 4 ‘Jurisprudence . . . is divisible into three branches, which may be distinguished as analytical, historical, and ethical’, cited in B. Tamanaha, ‘The Third Pillar of Jurisprudence: Social Legal Theory’, available at <http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2256622> (accessed on 27 January 2015).

4 I. Berlin, Montesquieu, Proceedings of the British Academy 41: 267, 289 (1955) (quoted in B. Tamanaha, Third Pillar, 8–9).

5 H. L. A. Hart, The Concept of Law (1994) 65, 146–7. The traditional reference is a quote from Holmes referenced as the bad man theory of law – ‘But if we take the view of our friend the bad man we shall find that he does not care two straws for axioms or deductions, but he does want to know what the Massachusetts or English courts are likely to do in fact. I am much of his mind. The prophecies of what the courts will do in fact, and nothing more pretentious are what I mean by the law’. Holmes, O. W., ‘The Path of the Law’, (1897) 10 Harvard Law Review 457Google Scholar, 460–1.

6 Leiter focuses on adjudication, although this is not the only interest of legal realists. See B. Leiter, Naturalizing Jurisprudence: Essays on American Legal Realism and Naturalism in Legal Philosophy (2007); J. Schlegel, American Legal Realism & Empirical Social Science (1995); and Nourse, V. and Shaffer, G., ‘Varieties of New Legal Realism: Can a New World Order Prompt a New Legal Theory?’, (2009) 95 Cornell Law Review 61Google Scholar.

7 Llewellyn, K., ‘Some Realism about Realism: Responding to Dean Pound’, (1931) 44 Harvard Law Review 1222CrossRefGoogle Scholar (legal realism as a ‘movement in thought and work about law’, and not a ‘school’).

8 See, e.g., Cohen, F. S., ‘Transcendental Nonsense and the Functional Approach,’ (1935) 35 Columbia L Review, 809CrossRefGoogle Scholar (referring to Holmes’ predictive theory).

9 Those taking such a latter position epistemologically, and who aim to explain law in scientific terms, have links with Scandinavian legal realism and what Mikael Madsen and Jacob Holtermann call New European Legal Realism. See J. Holtermann and M. Madsen, in this issue.

10 See, e.g., F. von Savigny, The Vocation of Our Age for Legislation and Jurisprudence (1981) (stressing law as a product of changing social forces); H. Maine, Ancient Law (1861) (noting the mechanisms used to close the gap between changes in society and outdated law, including the use of legal fictions and equity); R. von Jhering, The Struggle for Law (1879) (critiquing Savigny's focus on a ‘common consciousness’ as opposed to struggles between competing individuals and classes giving rise to law as a form of organized force); and E. Ehrlich, Fundamental Principles of the Sociology of Law (1937), 399 (‘The reason why the law is in a perpetual state of flux is that men, whose relations the law is designed to regulate, are continually posing new problems for it to solve’). Scandinavian legal realism is a distinct approach to law, but not one that influenced American legal realists.

11 Grisé, J. E.et al., ‘Rudolf Von Jhering's Influence on Karl Llewellyn’, (2012) 48 Tulsa Law Review 93Google Scholar; Brock, B. J., ‘Modern American Supreme Court Judicial Methodology and Its Origins: A Critical Analysis of the Legal Thought of Roscoe Pound’, (2011) 35 Journal of the Legal Profession 187, 206Google Scholar (stating that Pound ‘heavily relied on von Jhering’); Tidmarsh, J., ‘Resolving Cases “on the Merits”’, (2010) 87 Denver University Law Review 407, 418Google Scholar (‘Roscoe Pound was deeply influenced by the work of the German legal philosopher Rudolf von Jhering’); Grechenig, K. and Gelter, M., ‘The Transatlantic Divergence in Legal Thought: American Law and Economics vs. German Doctrinalism’, (2008) 31 Hastings International and Comparative Law Review 295, 314Google Scholar (stating that the legal realists were ‘under the influence of the criticism of conceptual jurisprudence brought forth earlier by Jhering’); Simmonds, A., ‘Amah and Eved and the Origin of Legal Rights’, (2001) 46 South Dakota Law Review 516, 531, 606Google Scholar (‘Pound's view was in the tradition of the University of Berlin school of Savigny and Jhering’).

12 Holmes and Pound declared Ehrlich's work, respectively, ‘the best book on legal subjects by any living continental jurists’ (Holmes), and ‘the best thing that has been written lately’ (Pound). Even though they arguably misconstrued Ehrlich, they used his work to develop their theories in their own contexts. See Nelken, D., ‘Law in Action or Living Law? Back to the Beginning in Sociology of Law’, (1984) 4 Legal Studies 157, 157–74CrossRefGoogle Scholar; Nelken, D., ‘Erlich's Legacies: Back to the Future in the Sociology of Law?’, in Hertogh, M. (ed.), Living Law: Reconsidering Eugen Ehrlich (2009), 237Google Scholar (Llewellyn stated that he was ‘somewhat crushed in spirit’ given how much Ehrlich had done. Quoted in N. E. H. Hull, R. Pound, and K. Llewellyn, Searching for an American Jurisprudence (1997), 108–10.

13 See Ehrlich, E., ‘Judicial Freedom of Decision: Its Principles and Objects’, in Drake, J. H.et al. (eds.), Science of Legal Method: Select Essays (1969), 47, 78Google Scholar.

14 See discussion in Nourse and Shaffer, ‘Varieties of New Legal Realism’, supra note 6; W. de Been, Legal Realism Regained: Saving Realism from Critical Acclaim (2008).

15 See, e.g., Llewellyn, K., ‘Through Title to Contract and a Bit Beyond’, (1938) 15 New York University Law Review 159Google Scholar.

16 The conventional positivist definition of ‘methodology of legal research’ is the ‘ways to identify and locate primary and secondary sources’. See S. Rosenne, Practice and Methods of International Law (1984) (cited in Ratner, S. R. and Slaughter, A., ‘Appraising the Methods of International Law: A Prospectus for Readers’, (1999) 93 AJIL 291, 292CrossRefGoogle Scholar).

17 Grey, T., ‘What Good is Legal Pragmatism?’, in Brent, M. and Weaver, W. (eds.), Pragmatism in Law and Society (1991), 9, 12Google Scholar.

18 L. Fuller, The Morality of Law (1964). See also D. Dyzenhaus, ‘Accountability and the Concept of (Global) Administrative Law’, in (2009) Acta Juridica 3; Kingsbury, B., ‘The Concept of “Law” in Global Administrative Law’, (2009) 20 EJIL 23–57CrossRefGoogle Scholar.

19 R. Dworkin, Freedom's Law: The Moral Reading of the American Constitution (1997), 410–11. Dworkin's theory of law, in my view, is primarily an adjudicative theory of the principled, integrative way that judges should reason, and, subject to empirical study, a claim regarding the way they actually do reason. Ibid., at 411.

20 See J. Dewey, Essays in Experimental Logic (1916); Nourse and Shaffer, ‘Varieties of New Legal Realism’, supra note 6. For a more recent application in this vein, see A. Sen, The Idea of Justice (2009).

21 See further elaboration in Nourse, V and Shaffer, G., ‘Empiricism, Experimentalism, and Law: Toward a Dynamic New Legal Realism,’ (2014) 67 Southern Methodist University Law Review 101Google Scholar.

22 De Been, supra note 14.

23 See, e.g., Cohen, supra note 8, at 835 (‘A definition of law is useful or useless. It is not true or false’); Cook, W. W., ‘Scientific Method and the Law’, (1927) 13 American Bar Association Journal 303, 306Google Scholar (‘Any grouping . . . appears as at most a working hypothesis, to be tested by its consequences, and subject to revision in the light of further experience’). See Leiter, Naturalizing Jurisprudence, supra note 6. (reconstructing legal realism from the perspective of philosophical naturalism).

24 Pragmatists are not anti-scientific. See, e.g., S. Haack, Defending Science – Within Reason: Between Scientism and Skepticism (2003).

25 O. Holmes, The Common Law (1881), 1.

26 See Nourse and Shaffer, ‘Varieties of New Legal Realism’, supra note 6; Farber, D., ‘Toward a New Legal Realism’, (2001) 68 Chicago Law Review, 279, 279–303CrossRefGoogle Scholar; Broude, T., ‘Behavioral International Law’, (2015 forthcoming) 163 Pennsylvania Law ReviewGoogle Scholar.

27 See De Been, supra note 14 (arguing for a need to save legal realism from critical legal studies by focusing on legal realism's grounding in pragmatism).

28 For examples of critical work that call for a critical empiricism, see, e.g., Trubek, D., ‘Where the Action Is: Critical Legal Studies and Empiricism’, (1984) 36 Stanford Law Review 575CrossRefGoogle Scholar; Trubek, D. and Esser, J., ‘Critical Empiricism in American Legal Studies: Paradox, Program or Pandora's Box?’, (1989) 14 Law and Social Inquiry 3CrossRefGoogle Scholar; Harrington, C. and Yngvesson, B., ‘Interpretive Sociolegal Research’, (1990) 15 Law and Social InquiryCrossRefGoogle Scholar. For examples of work tending to eschew empirical study, see, e.g., Koskenniemi, M., ‘Law, Teleology and International Relations: An Essay in Counterdisciplinarity’, (2014) 26 International Relations 3CrossRefGoogle Scholar; Kelman, M., ‘Trashing’, (1984) 36 Stanford Law Review, Critical Legal Studies Symposium 293, 337–43CrossRefGoogle Scholar.

29 Shaffer, G. and Ginsburg, T., ‘The Empirical Trend in International Law’, (2012), 106 AJIL 1CrossRefGoogle Scholar.

30 The legal realists also were not very interested in comparative law approaches either. See Merryman, J. H., ‘Comparative Law Scholarship’, (1998) 21 Hastings International and Comparative Law Review 771, 781Google Scholar.

31 See, e.g., D. Held et al., Global Transformations: Politics, Economics, and Culture (1999), 14–28; A. Appadurai, Modernity at Large: Cultural Dimensions of Globalization (1996); and Michaels, R., ‘Globalisation and Law: Law Beyond the State’, in Banakar, R. and Travers, M. (eds.) Law and Social Theory (2013), 287Google Scholar.

32 The term transnational can be defined in different ways. Phillip Jessup defined transnational law as ‘all law which regulates actions or events that transcend national frontiers’, which includes public and private international law but extends beyond them. P. Jessup, Transnational Law (1956), 2. Following, but also differentiating from, Jessup, I have defined transnational law more broadly as the construction and flow of legal norms implicating persons, entities, and/or institutions in more than one nation-state. See G. Shaffer, Transnational Legal Ordering and State Change (2013).

33 On the rise and proliferation of international courts, see K. Alter, The New Terrain of International Law: Courts, Politics, Rights (2014).

34 Holmes, ‘The Path of the Law’, supra note 5, at 4.

35 See H. D. Lasswell and M. S. McDougal, Jurisprudence for a free society: studies in law, science and policy (1992); Reisman, M., Wiessner, S., and Willard, A., ‘Commentary: The New Haven School: A Brief Introduction’, (2007) 32 The Yale Journal of International Law, 575Google Scholar.

36 See, e.g., Dorsey, G., ‘Agora: McDougal-Lasswell Redux: The McDougal-Lasswell Proposal to Build a World Public Order’, (1988) 82 AJIL 41CrossRefGoogle Scholar, 49 (‘Julius Stone pointed out that in none of these studies did McDougal and associates make the comprehensive empirical investigation that they specify for the scholars who are charged with building the world public order.’ Citing J. Stone, Visions of World Order 29 (1984)); Young, O. R., ‘International Law and Social Science: The Contributions of Myres S. McDougal’, (1972) 66 AJIL 60CrossRefGoogle Scholar, 63 (‘[I]t is hardly surprising that McDougal is a great advocate, at least at the verbal level, of expanding the use of findings from the social sciences in legal analysis. What is somewhat surprising, however, is that McDougal's substantive contributions to the achievement of this objective are not particularly impressive and that the opportunities for introducing findings from the social sciences far outdistance their actual introduction in his own work.’).

37 See, e.g., Leiter, B., ‘American Legal Realism’, in Patterson, D. and Edmundson, W. A. (eds.), A Companion to Philosophy of Law and Legal Theory, (2010) 50, 61Google Scholar (‘Scholars at Yale (notably Harold Lasswell and Myres McDougal) propounded a watered-down version of Realism under the slogan of “policy science”. . . . “Policy science” is now, happily, defunct, since it had far more to do with rationalizing American imperialism than it did with science’); O’Connell, M. E., ‘New International Legal Process’, (1999) 93 AJIL 334, 350CrossRefGoogle Scholar (New Haven School's ‘policies and norms are those of its creators and that they were too closely tied to the interest of the United States to be the norms of the international community’. Citing A. Carty, The Decay of International Law? (1986)).

38 This context, in theory, could of course change, but it remains the context in which law operates and develops today.

39 See Shaffer, Transnational Legal Ordering, supra note 32; T. Halliday and G. Shaffer, Transnational Legal Orders (forthcoming 2015).

40 See Ratner, S. R. and Slaughter, A.-M., ‘Appraising the Methods of International Law: A Prospectus for Readers’, (1999) 93 AJIL 291CrossRefGoogle Scholar. They also cite Philip Allott for the proposition that ‘methods . . . refer to the structure of their argumentation, in particular its logical discourse’. Ibid., at 292.

41 See G. Shaffer and T. Ginsburg, Empirical Work in International Law: A Bibliographical Essay (2009), 8–9 available at <http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1444448> (accessed 28 January 2014) (providing data on publications on international law topics in flagship journals on international relations, law and society, and law and economics).

42 See, e.g., R. Bernstein, The Pragmatic Turn (2010); D. Davidson, ‘Truth Rehabilitated’ in Truth, Language, and History 3–18 (2005); H. Putnam, Pragmatism (1994); W. V. Quine, Two Dogmas of Empiricism, in From a Logical Point of View (1980); R. Rorty, Philosophy and the Mirror of Nature (1979); L. Wittgenstein, Philosophical Investigations (1953).

43 Quine, Two Dogmas of Empiricism, supra note 42, at 20 (1980); see also W. V. Quine, Epistemology Naturalized, in Ontological Relativity and Other Essays 69 (1969) (maintaining that our very thinking is constructed within a context from which it cannot be completely free).

44 See K. Llewellyn, ‘Some Realism about Realism’, supra note 7 (not a ‘school’).

45 H. Kelsen, Pure Theory of Law (1967), 87–8 (‘A legal norm is valid even if it is not wholly effective – it suffices if it is effective “by and large”, that is, if it is applied and obeyed to some degree’); H. L. A. Hart, The Concept of Law (1961), 235 (‘The rules of the simple structure [international law] are, like the basic rule of the more advanced system, binding if they are accepted and function as such’). Hart addressed validity at the system level for advanced legal systems, but noted that international law is analogous to the rules of a primitive society in which there is no rule of recognition.

46 See R. Steinberg, ‘Wanted: Dead or Alive – Realist Approaches to International Law’, in J. Dunoff and M. Pollack, Interdisciplinary Perspectives on International Law and International Relations: The State of the Art (2012), 153–4 (discussing different variants of IR realism and their claims).

47 See Shaffer and Ginsburg, ‘The Empirical Trend’, supra note 29.

48 See, e.g., Dewey, J., ‘Logical Method and Law’, (1924) 10 Cornell Law Quarterly 17, 26Google Scholar; K. N. Llewellyn, The Bramble Bush (1930), 70–5; K. N. Llewellyn, ‘Major Steadying Factors in our Appellate Courts’, in The Common Law Tradition: Deciding Appeals (1960), 19.

49 See Cook, supra note 23, at 308 (‘human laws are devices, tools which society uses as one of its methods to regulate human conduct’).

50 See De Been, supra note 14, at 21. See also Lang, this issue.

51 Nourse and Shaffer, ‘Empiricism, Experimentalism, and Law’, supra note 21.

52 This research was published in Shaffer, G., ‘The World Trade Organization under Challenge: Democracy and the Law and Politics of the WTO's Treatment of the Trade and Environment Matters’, (2001) 25 Harvard Environmental Law Review 1, 1–93Google Scholar.

53 For an example of how this work might inform interpretive choices, see G. Shaffer, ‘Power, Governance, and the WTO: A Comparative Institutional Approach’, in M. Barnett and B. Duvall, Power in Global Governance (2005), 130.

54 See J. Brunée and S. J. Toope, Legitimacy and Legality in International Law (2010) (applying a process-based approach building from Lon Fuller and his theories of social interaction which can also be viewed in social constructivist terms).

55 Llewellyn, K., ‘The Normative, The Legal, and the Law-Jobs: The Problem of Juristic Method’, (1940) 49 Yale Law Journal 1355CrossRefGoogle Scholar, at 1358–9 (referring to different forms of ‘incipient law’ which was not yet ‘imperative’. As he writes, ‘“the legal” under immediate discussion is a very bare-bones kind of legal stuff; pre-law ways, if you will’).

56 Shaffer, G. and Pollack, M., ‘Hard vs. Soft Law in International Governance’, (2010) 94 Minnesota Law Review 706Google Scholar.

57 See N. Duxbury, Patterns of American Jurisprudence (1997).

58 Singer, J. W., ‘Legal Realism Now’, (1988) 76 California Law Review 465, 505–8CrossRefGoogle Scholar. Hart and Sachs emphasized the role of institutions in the legal process, as opposed to a formalists’ focus on legal texts. See William N. Eskridge, Jr., and Phillip P. Frickey, ‘An Historical and Critical Introduction to the Legal Process’, in H. M. Hart, Jr. and A. M. Sacks, The Legal Process: Basic Problems in the Making and Application of Law, at lix–lxii (William N. Eskridge, Jr., and Phillip P. Frickey eds., 1994).

59 See, e.g., A. Chayes’ famous study of the Cuban missile crisis. A. Chayes, Cuban Missile Crisis (1974). See also Bodansky, this issue (applied to international environmental law). To adapt from Edward Rubin writing in a related theoretical frame, the New Legal Realism attends to ‘all the social forces, inequalities, and ideological [factors] that legal process theory ignored’. Edward L. Rubin, ‘Commentary: The New Legal Process, the Synthesis of Discourse, and the Microanalysis of Institutions’, (1996) 109 Harvard L. Review 1393, 1428.

60 On the transnational, see supra note 32.

61 See Shaffer, Transnational Legal Ordering, supra note 32; Halliday and Shaffer, supra note 39. For earlier characterizations of these transnational processes that are less social scientific and empirical in their focus, see Jessup, supra note 32; and Koh, H., ‘Transnational Legal Process’, (1996) 75 Nebraska Law Review 181Google Scholar.

62 Elkins, Z., Ginsburg, T., and Simmons, B., ‘Getting to Rights: Treaty Ratification, Constitutional Convergence, and Human Rights Practice’, (2013) 51 Harvard International Law Journal 201Google Scholar.

63 S. Merry Human Rights & Gender Violence: Translating International Law into Local Justice (2006).

64 See their respective chapters in Halliday and Shaffer, supra note 39.

65 One does not need to take a conceptual position regarding whether non-state law constitutes law to see Erlich's relevance for assessing the interaction of international law with other forms of normative ordering in the broader transnational context. See Nelken, ‘Erlich's Legacies’, supra note 12 (2009) (noting different reconstructions and appropriations of Ehrlich in the current context).

66 See J. Goldsmith and E. Posner, The Limits of International Law (2006); E. Posner, The Perils of Global Legalism (2009); Steinberg, Wanted, supra note 46.

67 See also Madsen and Holtermann, this issue (on the conditional autonomy of law).

68 For examples and further explication, see Shaffer and Ginsburg, ‘The Empirical Trend’, supra note 29. (appraising the empirical trend in international legal scholarship using multiple methods, as a means to build conditional theory); and Nourse and Shaffer, ‘Empiricism Experimentalism, and Law’, supra note 21.

69 Dagan, H., ‘The Realist Concept of Law’, (2007) 57 University of Toronto Law Journal 607, 608CrossRefGoogle Scholar. Nourse and Shaffer, ‘Varieties of New Legal Realism’, supra note 6; Nourse and Shaffer, ‘Empiricism, Experimentalism, and Law’, supra note 21.

70 On legal reason as a form of practical reason, see Postema, G., ‘Law's Autonomy and Public Practical Reason’, in George, R. (ed.) The Autonomy of Law: Essays on Legal Positivism (1996)Google Scholar. On different variants of power, see Barnett and Duvall, supra note 53.

71 Dworkin, Freedom's Law, supra note 19, at 36 (‘They said there is no such thing as law’).

72 See Kelsen, supra note 45, at 353 (interpretation as politics and outside of his pure theory of law).

73 See Jhering, supra note 10.

74 See Llewellyn, The Bramble Bush, supra note 48, at 70–5; Llewellyn, ‘Major Steadying Factors’, supra note, at 48.

75 See Shaffer, Transnational Legal Ordering, supra note 32; Halliday and Shaffer, supra note 39. See also Holtermann and Madsen, in this issue (on law's symbolic power).

76 For other examples, see Shaffer, G., ‘New Legal Realism in International Law’, in Klug, H., Mertz, E., and Merry, S. Engle (eds.) Studying Law Globally: New Legal Realist Perspectives (Vol II), (2015)Google Scholar, as well as the other articles in this issue.

77 J. Trachtman, ‘The Jurisdiction of the WTO’, (2004) Proceedings of the 98^th Annual Meeting of the American Society of International Law 139.

78 See Pauwelyn, J., ‘How to Win a WTO Dispute Based on Non-WTO Law’, (2003) 37 Journal of World Trade 997Google Scholar.

79 See Shaffer and Pollack, ‘Hard vs. Soft Law’, supra note 56; Shaffer, G. and Pollack, M., ‘A Structural Theory of WTO Dispute Settlement: Why Institutional Choice Lies at the Center of the WTO Case’, (2008) 41 NYU Journal of International Law and Politics 1Google Scholar.

80 Shaffer and Pollack, ‘Hard vs. Soft Law’, supra note 56.

81 See, e.g., I. Venzke, How Interpretation Makes International Law: On Semantic Change and Normative Twists (2012) (giving a detailed example of the administrative context of the UNHCR).

82 See Shaffer and Pollack, ‘Hard vs. Soft Law’, supra note 56.

83 See T. Tyler, Why People Obey the Law (2006); and Halliday and Shaffer, supra note 39 (on the settlement of legal norms).

84 See, e.g., R. West, Normative Jurisprudence: An Introduction (2011)(providing a normative critique from within critical legal studies of the turn away from normativity in critical legal scholarship).

85 A. Huneeus, this issue; H. Dagan, ‘Lawmaking for Legal Realists’, in Legisprudence (forthcoming 2014); Nourse and Shaffer, ‘Varieties of New Legal Realism’, supra note 6; Nourse and Shaffer, ‘Empiricism Experimentalism, and Law’, supra note 21.

86 E. A. Purcell, Jr., The Crisis of Democratic Theory: Scientific Naturalism & the Problem of Value (1973), 82–5.

87 See Huneeus this issue (regarding why social science needs law as much as law needs social science).