This book addresses current practices in customary law. It includes contributions by scholars from various legal systems (the USA, France, Israel, Canada et cetera), who examine the current impacts of customary law on various aspects of private law, constitutional law, business law, international law and criminal law. In addition, the book expands the traditional concept of the rule of law, and argues that lawyers should not narrowly focus on statutory law, but should instead pay more attention to the (...) impact of practices on "real legal life." It states that the observation of practices calls for a stronger focus on usage, customs and traditions in our legal systems - the idea being not to replace statutory law, but to complement it with customary observations. (shrink)

In constitutional scholarship, legal sanctions and customary law seem to be opposed to each other: customary law is often defined precisely as law without sanctions. Applied to the constitutional field, it is possible to better define those two elements of discourse: constitutional sanctions are essentially procedures of constitutional review of legislation, while customary law is more frequently referred to as constitutional conventions. While insisting on the presence of the element of sanction is typical of the normative discourse (...) attributed to Hans Kelsen, stressing the importance of constitutional conventions implies different strategic goals. Those goals are related to the definition of constitutional law and its specificity compared to other –less political– legal fields. (shrink)

Although many modern philosophers of law describe custom as merely a minor source of law, formal law is actually only one source of the legal customs that govern us. Many laws grow out of custom, and one measure of a law's success is by its creation of an enduring legal custom. Yet custom and customary law have long been neglected topics in unsettled jurisprudential debate. Smaller concerns, such as whether customs can be legitimized by practice or by stipulation, stipulated (...) by an authority or by general consent, or dictated by law or vice versa, lead to broader questions of law and custom as alternative or mutually exclusive modes of social regulation, and whether rational reflection in general ought to replace sub-rational prejudice. Can legal rules function without customary usage, and does custom even matter in society? The Philosophy of Customary Law brings greater theoretical clarity to the often murky topic of custom by showing that custom must be analyzed into two more logically basic concepts: convention and habit. James Bernard Murphy explores the nature and significance of custom and customary law, and how conventions relate to habits in the four classic theories of Aristotle, Francisco Suarez, Jeremy Bentham, and James C. Carter. He establishes that customs are conventional habits and habitual conventions, and allows us to better grasp the many roles that custom plays in a legal system by offering a new foundation of understanding for these concepts. (shrink)

This paper examines the extent to which dispute resolvers in customary law systems provide widely understandable justifications for their decisions. The paper first examines the liberal-democratic reasons for the importance of publicity, understood to be wide accessibility of legal justification, by reviewing the uses of publicity in Habermas’ and Rawls’ accounts of the rule of law. Taking examples from Sierra Leone, the paper then argues that customary law systems would benefit from making local dispute resolution practices, such as (...) “begging” from elders, witchcraft, and customary law judgments, more widely accessible. The paper concludes that while legal pluralism is usually taken to be an analytical concept, it may have a normative thrust as well, and that publicity standards would also apply to formal courts in developing countries, which are also typically “defective” along this dimension. (shrink)

Some legal rules are not laid down by a legislator but grow instead from informal social practices. In contract law, for example, the customs of merchants are used by courts to interpret the provisions of business contracts; in tort law, customs of best practice are used by courts to define professional responsibility. Nowhere are customary rules of law more prominent than in international law. The customs defining the obligations of each State to other States and, to some extent, to (...) its own citizens, are often treated as legally binding. However, unlike natural law and positive law, customary law has received very little scholarly analysis. To remedy this neglect, a distinguished group of philosophers, historians and lawyers has been assembled to assess the nature and significance of customary law. The book offers fresh insights on this neglected and misunderstood form of law. (shrink)

The main goal of this article is to analyse the current status of the precautionary principle in international law and outline the tendencies of its development into a rule of customary law. The methods of comparative and systematic analysis were used in this paper. The article concludes that there is sufficient state practice and opinio iuris to support the position of the European Communities that the precautionary principle has already crystallized into a general customary rule. Evidence may be (...) found in international legally binding and non-binding documents, domestic law, and the jurisprudence of national and international courts and tribunals. (shrink)

Explaining what made ancient Greek law unusual, Michael Gagarin observes that most premodern legal cultures “wrote extensive sets of laws for academic purposes or propaganda but these were not intended to be accessible to most members of the community and had relatively little effect on the actual operation of the legal system.” This article addresses the implications of writing for customary or regional law in South and Southeast Asia. The textual tradition of Dharmaśāstra, which canonizes a particular model of (...) Brahmin customary norms, can certainly be called a “scholarly” exercise, and it was also intended as propaganda for the Brahmanical cosmopolitan world order. But it also formulated a procedural principle to recognize the general validity of other, even divergent, customary norms, though for the most part such rules remained lex non scripta. On the other hand, inscriptions provide evidence that writing was used for diverse legal purposes and offers glimpses of actual legal practice. In these records, customary laws are sometimes laid down as statutes by decree of a ruler or community body, or are simply invoked as long-established customary rules. But even when Dharmaśāstra texts are not directly cited, their influence over the longue durée is discernable in the persistence of śāstric legal categories and terms of art. This influence is even more evident in Java, where legal codes on the Dharmaśāstra model were composed in Javanese, and where the inscriptions came to exhibit a closer connection with śāstric discourse than is found in India. (shrink)

The present essay addresses the conceptual structure of customary law, understood as a set of customary rules. More specifically, it deals with the core question of what opinio juris entails as a constituent element of customary law. The work will begin with an analysis of samples of common strategies in contemporary legal theory that deal with opinio juris when analyzing the structure of customary law. Subsequently, following Hart’s notion about what constitutes social rules, and introducing explanatory (...) features from Game Theory applied to social philosophy and some insights from Behavioral Economics, the goal of the present study is to propose a different conceptual path for analyzing and identifying customary law with what could be understood as “opinio juris”, given the conceptual necessity of finding the normative element that lies within the usus, or social practices. (shrink)

The Russian conquest of Central Asia marked the beginning of record-keeping for Qazaq arbitrators and customary law. It remains obscure how bīs complied with the colonial regulations obliging them to record their court proceedings. I approach this issue first by questioning the utility of extra-judicial sources crafted in Russian at the instigation of colonial bureaucrats; hence, I argue that the comparison alone of ’ādat-related judicial records written in Turki with šarī’a court certificates allows situating the legal terminology applied by (...) Qazaq arbitrators within the discursive tradition of Islamic law. By way of illustrating my approach, I offer a close reading of a report of a murder case adjudicated according to Qazaq customary law in the vicinity of Khiva in 1895. My commentary on the summary of the trial sheds light on the interplay of customary and Islamic law in the region. In addition, it challenges earlier interpretations of the use of the exculpatory oath among the Qazaqs. (shrink)

RESUMEN: La labor del Tribunal Penal Internacional para la Ex-Yugoslavia tuvo un momento importante en la compresión del principio de legalidad, como principio básico en la garantía de los derechos humanos, al enfrentar no sólo el derecho consuetudinario como fuente de derecho sino también diferentes modos o enfoques en la identificación de este derecho consuetudinario. Esta relación debe ser analizada a la luz de las limitaciones que tiene el derecho internacional y, sobre todo, de los procedimientos de creación de normas. (...) No resulta fácil exigir responsabilidad en el cumplimiento del derecho internacional humanitario y de los derechos humanos. La práctica de este Tribunal abre una vía para la reflexión con la finalidad de asegurar el respeto de los derechos humanos en cualquier circunstancia, incluso de aquellos que llevaron a cabo la comisión de graves crímenes contra la comunidad internacional.ABSTRACT: The work of the International Criminal Tribunal for the former Yugoslavia was important for understanding the principle of legality as a key principle on the guarantee of Human Rights. The former was due to the Tribunal’s work on having faced the customary law as a source of law using different perspectives for its identification. The link between customary law, principle of legality and human rights has to be analyzed taking in account the limits of International law and the procedures for creating legal norms. It is not easy to invoke responsibility in the fulfillment of international humanitarian law and international law of human rights. The practice developed by this Tribunal provides an avenue for thinking about ensuring the respect of the human rights in any case including the commission of grave crimes against international community. PALABRAS CLAVE: derecho internacional de los derechos humanos, principio de legalidad, derecho internacional humanitario, costumbre internacionalKEYWORDS: international law of human rights, principle of legality, international humanitarian law, international custom. (shrink)

The paper presents a novel take on the character of South Africa’s governance structure. It argues that, insofar as it constitutionally recognises traditional authorities, figures who rule in accordance with idiosyncratic and localised customary laws, as well as instigate a cheek-by-jowl existence of an asymmetrical property law (where in the urban setting land is nominally bought or transferred for sale, but in traditional rural areas granted by the chief), manifest in the differentiated land laws brought about by the Communal (...) Land Rights Act of 2003, is more akin to, and necessitates a definitional alignment with, the federal system of government than a unitary one – or at least a weak “federalism with South African characteristics.”. (shrink)

The ethical authority carried in the conventions of fairness and human well-being has been widely adopted under the idea of “moral economy,” forming an eclectic and interdisciplinary debate. Significant, though external to this debate, is a corpus of medieval thought which exhibits a fundamental interest in legitimate market protocols, and the political rights and obligations of agents in relation to the common good of the community. This article asserts the imperative status of a customary basis for understanding not just (...) the analytic version of moral economy but the legacy contained in what might be termed the “the moral economy of Aquinas.”. (shrink)

Assisted migration (AM) is a translocation of the representatives of species to areas outside their natural habitats as a response to climate change. This article seeks to identify how customary norms and general principles of international environmental law could guide the development of regulation of AM maximizing the benefits of using AM and minimizing AM-related risks. Among the customary norms and principles of international environmental law discussed in the article and relevant to the regulation of AM are the (...) permanent sovereignty over natural resources, the principle of cooperation, the no-harm rule, the precautionary principle, the principles of prevention, due diligence, and obligation to conduct environmental impact assessment (EIA), the principles of integration and intergenerational equity, common but differentiated responsibilities, and the polluter pays principle, the principles of non-regression, progression, resilience, in dubio pro natura, the principle of ecological proportionality, and the principle of access to information, public participation, and access to justice in environmental matters (principle of good governance, environmental democracy). (shrink)

After the French Revolution, the codification movement led to the introduction of the Dutch Civil Code and the Commercial Code of 1838. These codifications were generally regarded as the bedrock of a dogmatic system in which little space was left for customs and customary law. Mercantile jurists, such as Holtius and Levy, were opponents of the legalistic approach of the new codifications. They tried to separate mercantile law from civil law in order to protect mercantile law from excessive legalistic (...) influences. According to them, mercantile law was characterised by internationality, custom as its main source of law, continuity through an extended mercantile legal history and by good faith and mutual trust between the merchants. Out of these, the historicity and homogeneity of a strong community of merchants are particularly in line with a traditional and conservative view on society. Holtius and Levy, however, had little in common with their Christian-conservative contemporaries. On the one hand, they rather seemed to foreshadow the kind of liberal-conservatism as expressed by Hayek during the 20th century. On the other hand, their ideas have much in common with different lex mercatoria –traditions developed by authors as Goldman and Schmitthoff. On the aspects of historicity and internationality Holtius and Levy seem to have much in common with Hayek whereas concerning communality and the legal nature of customary law there are more similarities with the lex mercatoria-traditions. (shrink)

Law wrangles with setting and applying standards for the practice of medicine in many different arenas. One of the most prominent is medical malpractice litigation in which the trial process examines a physician's performance and measures it against the standard of care. The profession's prevailing custom, with some substantial tolerance for “respectable minority” views, has been the gold standard for scrutinizing physician practice and treatment decisions in the malpractice context. Using the profession's custom as the measure against which a physician's (...) performance is judged defers to the expertise of medicine. Deference to the medical profession is attractive as a tool for reining in law. Reliance on customary practice is criticized, however, for driving physicians to the relative safety of the middle of the herd. Creating such a strong incentive for compliance with customary practice can dampen medical innovation and the diffusion of new clinical knowledge. The safety of the herd can also deprive individual patients of the best care in their particular circumstances.Several current trends are strengthening claims that professional practice patterns are an inappropriate tool for distinguishing between high‐quality and substandard care. In particular, advocacy for evidence‐based medicine aggressively asserts that the traditional way of making medical treatment decisions is largely untethered from scientific method or data, rendering professional judgment, even in the aggregate, suspect. (shrink)

Superior responsibility has been a widely recognised form of responsibility for omission in both treaty and customary international law. Superiors are held responsible for the acts of their subordinates when they fail in fulfilling their duties to prevent or punish crimes of subordinates. Duties to prevent and punish arise only after the superior knows about the subordinate’s crimes or has a reason to know about it. ‘Has a reason to know’ is a form of constructive knowledge and could be (...) defined as absence of actual knowledge about subordinates’ crimes where that knowledge should exist because of information available to the superior from the content of which it could be easily concluded that there is a possibility that subordinates intend to commit, are committing or have already committed crimes and the lack of that knowledge is a cause of willful disregard of his duties or at least disregard based on gross negligence. (shrink)

In this paper, I first discuss the concept of ‘Grotian Moment’ in the context of the capacity of international organizations to contribute to the formation and identification of customary international law. Afterward, I apply three levels to discuss the time element of the formation of custom. At the micro-level of the institutional practice, the time required to form a customary norm may depend on whether each form of practice is directed to the institutional or to the international dimension. (...) At the level of the organ, I reflect on the difference played by the presence or absence of member States in the institutional organ that adopts the practice relevant for custom formation. At the macro-level of the characteristics of the organization, I distinguish between so-called supranational and functional organizations. In general, I exclude the relevance of speaking in terms of a ‘Moment’ that produces a paradigm shift, and I stress the continuous change to which international law is subject. (shrink)

As traditionally conceived, the creation of a new rule of customary international law requires that states believe the law to already require the conduct specified in the rule. Distinguishing the process whereby a customary rule comes to exist from the process whereby that customary rule becomes law dissolves this chronological paradox. Creation of a customary rule requires only that states come to believe that there exists a normative standard to which they ought to adhere, not that (...) this standard is law. What makes the customary rule law is adherence by officials in the international legal system to a rule of recognition that treats custom as a source of valid law. Confusion over this distinction arises because in the international legal system the same agents whose beliefs give rise to a customary rule are the legal officials whose adherence to the rule of recognition leads them to deem that rule legally valid. The proposed solution to the chronological paradox employs H.L.A. Hart’s analysis of the concepts of law and a legal system, and in particular, the idea of a rule of recognition. Yet Hart famously denies the existence of a rule of recognition for international law. Hart’s denial rests on a failure to distinguish between the ontological and authoritative resolution functions of a rule of recognition, however. Once such a distinction is drawn, it can be argued that customary international law rests on a rule of recognition that serves the ontological function of making customary norms legal, though not the authoritative resolution function of settling disputes over the alleged legality of particular norms. (shrink)

Africa, before European colonization, knew no other form of legal system outside customary arrangements. Based on secondary sources and a primary survey conducted between 2009 and 2010 on the situation of women and land rights in anglophone Cameroon, this paper examines the grounds for discrimination in customary laws against women's rights to land in the context of legal pluralism, and discusses the implications of this custom of gender discrimination. In drawing from Cameroon as an exemplar, it concludes that (...) the strong influence and impact of customs on current land tenure systems have global implications on women's land rights, food security and sustainable development, and that gender equality in land matters can be possible only where the critical role of ethics is recognized in pursuit of the economic motive of land rights. (shrink)

This volume offers a critical analysis and illustration of the challenges and promises of ‘stateless’ law thought, pedagogy and approaches to governance - that is, understanding and conceptualizing law in a post-national condition. Confronting the ‘transnational challenge’ posed to the traditional theoretical and institutional structures that underlie the teaching and study of law in the university, the book brings new insight to the ongoing and crucial conversation about the future shape of legal scholarship, education and practice that is emblematic of (...) the early twenty-first century. (shrink)

In many parts of Africa three different systems of laws are concurrently applied – the imported "Colonial" law, the indigenous customary law and Islamic law. In some countries the customary and the Islamic law are kept separate and distinct, while in others they are fused into a single system. This volume represents a unique survey of the extent to which Islamic law is in fact applied in those parts of East and West Africa which were at one time (...) under British administration. It examines the relevant legislation and case law, much of which has never appeared in any Law Reports; the judges and courts which apply it and the problems to which its application give rise. (shrink)

A theory of customary international law -- Case studies -- A theory of international agreements -- Human rights -- International trade -- A theory of international rhetoric -- International law and moral obligation -- Liberal democracy and cosmopolitan duty.

Demonstrating that a developing norm is not yet well established in international law is frequently thought to show that states are not bound by the norm as law. More precisely, showing that a purported international legal norm has only limited support from well-established international legal sources is normally seen as sufficient to rebut an obligation on the part of subjects to comply with the norm in virtue of its legal status. I contend that this view is mistaken. Nascent norms of (...) international law (e.g., crystallizing norms of customary law) can be binding in much the same way as better-established doctrine. This point becomes perspicuous, I argue, once we get a clear sense of the plausible options for grounding the moral authority of international law generally. -/- This result is interesting in its own right, but it also reveals two other features of the character of state responsibility under international law. First, the distinction between legislation and compliance is less pronounced compared to domestic law. Consequently, the virtues of good governance will frequently be pertinent to determining the content of states’ obligations under international law. Second, normally more powerful and influential agents will be more strongly bound by international law than other subjects. This is an attractive result, addressing a concern that motivates many international lawyers to view international law as absolutely binding. An absolutist view international legal authority is unnecessary for showing that the most powerful and dangerous states are strongly bound by the terms of much existing law. (shrink)

Assembling a series of voices from across the field, this book demonstrates how posthuman theory can be employed to better understand and tackle some of the challenges faced by contemporary international law. With the vast environmental devastation being caused by climate change, the increasing use of artificial intelligence by international legal actors, and the need for international law to face up to its colonial past, international law needs to change. But in regulating and preserving a stable global order in which (...) states act as its main subjects, the traditional sources of international law - international legal statutes, customary international law, historical precedents and general principles of law - create a framework that slows down its capacity to act on contemporary challenges, and to imagine futures yet to come. In response, this collection maintains that posthuman theory can be used to better address the challenges faced by contemporary international law. Covering a wide array of contemporary topics - including environmental law, the law of the sea, colonialism, human rights, conflict, and the impact of science and technology - it is the first book to bring new and emerging research on posthuman theory and international law together into one volume. This book's posthuman engagement with central international legal debates, prefaced by the leading scholar in the field of posthuman theory, provides a perfect resource for students and scholars in international law, as well as critical and socio-legal theorists, and others with interests in posthuman thought, technology, colonialism and ecology. (shrink)

Toward the end of the twentieth century, Highland Maya intellectuals and activists in Guatemala began to argue for the recognition of indigenous customary law, rooted in traditional Maya moral and ritual discourse. Such law is often in tension with the Western notion of rights that undergirds national and international treatises regarding indigenous peoples. This essay identifies three distinct but mutually engaged pairs of moral concepts—hot/cold, left/right, and favorable/not favorable—articulated through K'iche' Maya quotidian and ceremonial practices and speech. It also (...) identifies the extent to which they do not necessarily align with Western notions of good and bad. These three pairs of moral terms, specifically as conserved through the high-register of Maya discourse used by traditional ceremonial specialists, illustrate a normative means by which Highland Maya discern understandings of justice, and ground their advocacy for restorative justice. (shrink)

The paper examines the realignment of the legal sources in an information society, by considering first of all the differences with the previous system of sources, dubbed as the “Westphalian model”. The current system is tripartite, rather than bipartite, for the sources of transnational law should be added to the traditional dichotomy between national and international law. In addition, the system is dualistic, rather than monistic, because the tools of legal constructivism, such as codes or statutes, have to be complemented (...) with the rules of customary law and contracts. In light of the canonical version of the law as a set of commands enforced through the threat of physical sanctions, however, two further novelties must be stressed, namely the soft law-tools of governance as a source of the system and the aim to embed normative constraints into technology, in order to enforce the law through the use of filtering systems, self-enforcing technologies, etc. This latter approach impacts on functions and requirements of the system, by transferring the normative side of the law from the traditional “ought to” of legal commands to what actually is on the basis of automatic techniques, thus affecting the very notion of source. The overall aim of the paper is to show that rearrangements of the legal sources are intertwined with redistributions of power and hence, a normative standpoint is needed, so as to determine whether scholars can obtain the solution that best justifies the integrity of the law before its hard cases, or the answer is a reasonable compromise between many conflicting interests. (shrink)

International Law in Context is a pedagogy-forward textbook. It reflects the recent paradigm shift in legal education, which focuses more on what students actually learn rather than the material to which they are exposed. The text aims to prepare the next generation of U.S. lawyers to engage with our interconnected world and to critically evaluate the U.S.'s role within the international legal order. The work is divided into three parts that accomplish these goals. Part One lays a foundation. It covers (...) the various actors within the system, the theories that help explain their behavior, and the principles and sources of law they create. Part Two turns to the fora that define and support the international order, the historical and political contexts that impacted their design, and their efficacy. Part Three is a capstone section that asks students to weave together everything they have learned in Parts One and Two. Students will engage in normative development regarding climate change, including the existing international treaty regime and U.S. implementation options, and the law of war in the modern age. The cornerstone of this book is its organization. The text groups material into conceptual frameworks that promote understanding and retention. For example, rather than consider the various dispute resolution fora in isolation, Part Two asks students to consider them in the context of what types of disputes arise and what legal rules can be employed to resolve them in various international and domestic fora. The institutions also are presented in chronology. In this way, students are encouraged to chart the developmental progression and to make connections and comparisons between various institutions. The use of conceptual frameworks continues within each part. For example, Chapter Six covers the sovereign State as a conflict resolution forum. Under this umbrella, the author discusses (a) State Jurisdiction; (b) The Reception of International Law into the Domestic Sphere; (c) The Qualification as a State Forum or State Litigant (i.e., Recognition of States & Governments); and (d) Protections Afforded Within the Forum: Sovereign, Diplomatic, and Consular Immunity. A typical coursebook might locate this material in four different chapters. The conceptual framework approach, however, allows students to see the big picture and the relationship between concepts. In addition to the frameworks, there are several other innovative pedagogical devices that support student learning. There are Foundation Questions that initially direct readers through the material and cumulatively help students confirm whether they have grasped key takeaways from each section. There also are Assessment Sets in each section, which provide students with immediate opportunities to apply material and gauge their understanding, and "Why Is This Important (a/k/a WITI Moment)" prompts designed to delve deeper into the underpinnings and consequences of various rules. Finally, there are directed reading notes before some more complex readings and margin annotations to keep readers oriented. (shrink)

This Article deals with legal transfer during the first decades after the foundation of the Bulgarian state in 1878, starting from the premise that law is based on communicative distinction rather than separation from society. Foreign law may therefore affect not only the native law, but also the form in which the latter is related to society. Thus legal transfer can also stimulate the evolution of law. The verification of this hypothesis is the aim of a greater project of which (...) the present Article is a part. The Bulgarian state relied a great deal at first on traditional practices of self-government and partly upon the modern Ottoman law, both of which were acknowledged by the Provisional Russian Rule in Bulgaria. Subsequently, Western law was eclectically imported at the expense of local traditions. It seems, however, that the "precious cargo" of modern Western law was relegated at first to the periphery of society, and the courts, for the most part consisting of elected laymen, experienced great difficulties in dealing with it, when it came to their knowledge at all. This is evidenced by customary law, and by some examples related to legal reasoning and legal critique, which may suggest both the persistence of traditional structures and their irritation through the transfer of foreign law. (shrink)

Can the concept of law be indiscriminately extended to times and places in which it did simply not exist? Such an extension is at best useless and at worst misleading. Producing an intelligible jurisprudence of the concept of law means keeping it within the reasonable boundaries of its contemporary common-sense understanding: positive law. Parallel to Western societies in which it firstly emerged, the concept of positive law developed in many places, including countries characterized as Muslim. There, it faced other existing (...) normativities, like customs and the Sharia. This book aims, from the Muslim world's perspective, to clarify the uses of the concept of law and the ways of studying it, to describe some of its historical developments, including the ideas of constitutional law, customary law and forensic evidence, and to describe present-day practices, including reference to law sources, rules and interpretation. (shrink)

The present paper addresses the mutual relationship between society and law in shaping women’s law in Islam from the perspective of the sociology of law. It analyzes the role of pre-Islamic social, political, and economic structures in the Arabian Peninsula in modeling women’s law and highlights some customary laws which were rejected or revived and integrated in Islamic jurisprudence. In this regard, the paper reviews issues such as polygyny, rights to inheritance, marriage, the process of testimony and acceptable forms (...) of evidence in legal matters, diyya, the exclusion of women from the judiciary and the system of issuing fatwa, natural right of guardianship of underage children after divorce, and regulations related to the veil. Finally, referring to the manner of the Prophet of Islam, the paper suggests that ʿurf can be considered as a source of Islamic legislation alongside other commonly known sources of fiqh. (shrink)

The purpose of this study seeks to analyze the problem of Unity in Diversity as a Source of Politics and Cultural Identity of the Indonesian Nation in Legal Formation. In general, the process of establishing customary, national, regional and international law in various parts of the world no one knows even uses Bhineka Tunggal Ika as the source of legal formation. However, often the formation of law in Indonesia refers to the philosophical meaning of Unity in Diversity. The formulation (...) of the research problem: 1) What are the markers of Unity in Diversity in Legal Formation?; 2) Why is Bhineka Tunggal Ika so important in the Formation of Law in Indonesia?; 3) Is there a contribution of Bhineka Tunggal Ika in the formation of customary law? This research was completed using qualitative methods. All data in this study are descriptive which have been collected directly or indirectly. Data acquisition is optimized through a literature study. All data were analyzed qualitatively to solve the research problem. The results showed that: 1) Unity in Diversity can be a marker of Indonesian national cultural identity in Legal Pluralism; 2) Bhineka Tunggal Ika in the formation of state law is considered relevant as a political source that is able to accommodate Customary Law and Religious Law into State Law; 3) Unity in Diversity as the identity of Indonesian Nation Culture, as well as political sources, has contributed in the spirit of the formation of Customary Law in the midst of the times. (shrink)