General Principles

Author: Craig Eggett

Required knowledge: Sources of International Law; others?

Learning objectives: To understand the background to article 38(1)(c) ICJ Statute; how general principles can be identified; what general principles (can) do in international law.

A. Introduction

Article 38(1) ICJ Statute’s list of generally-accepted sources of international law concludes with sub-paragraph (c)’s ‘general principles of law’. This source of law has received considerably less attention than treaties and customary law. For example, article 38 (1)(c) has never been explicitly relied on by the Court as a basis of a decision, being referenced in only a handful of proceedings. Further, academic discussion on this source of law had, until rather recently, been rather sparse. The discourse on general principles received a significant boost when, in 2017, the ILC decided to include the topic on its programme of work. Since then, the Commission has produced three reports and a set of draft conclusions on general principles and there has been a notable increase in scholarly attention on the topic. This chapter aims to provide an overview of the core aspects of the ongoing discussion on general principles in international law. To that end, it is structured around three main questions: (1) what kind of norms are general principles? (2) how are they ascertained? and (3) what functions do they perform? These questions overlap to an extent, yet they provide a basic logical structure to examine general principles and their place in the international legal system.

B. The Nature of General Principles

There has been considerable theoretical disagreement as to what exactly is meant by ‘general principles of law’. In other words, what exactly is it that we are talking about when we refer to the norms in article 38(1)(c) ICJ Statute? This question has implications for the identification and functioning of general principles, in addition to touching upon some fundamental aspects of the international legal system as such. To add further complexity to this question, it is also the case that the term ‘general principles’ is used in a more rhetorical sense to underline the importance or general scope of application of these norms. So, as an initial point, it is important to clarify that this chapter is concerned with general principles in the technical sense of article 38(1)(c) ICJ Statute.

That being said, the range of positions and perceived importance of general principles vary greatly. These norms could be seen as fundamental building blocks of the international legal system, as technical procedural norms, or merely as a tool for the interpretation of treaties and customary law. The ILC’s first draft conclusion provides a starting point for this question. It reads: ‘The present draft conclusions concern general principles of law as a source of international law.’ As indicated in the previous sub-chapter, authors may disagree as to what exactly it means to refer to a ‘source’ of law. Yet, this draft conclusion, as the ILC explains, confirms the legal nature of general principles of law. The following sections examine this legal nature by considering, first, the historical background of general principles in the international legal system and, second, the conceptual aspects of the normative classification of general principles and their relationship with other norms and concepts.

C. History and Origins of General Principles in International Law

Indeed, both the wording and history of the ICJ Statute confirm that general principles, whatever they may be, have a role as applicable law in the settlement of disputes. The drafting of article 38 ICJ Statute is based on the corresponding provision of the PCIJ Statute, which contains identical wording in relation to general principles, noting that ‘[t]he Court shall apply general principles of law recognized by civilized nations’. This wording – shall apply – confirms the role of general principles as an applicable source of law. The notion that general principles of law are a source available to judges in adjudicating a dispute has a history extending further back than the drafting of even the PCIJ Statue. For example, references to ‘principles’ as a source of applicable law were included in the Arbitral Procedure Regulations 1875, the First Hague Convention establishing the PCA, and the Convention Relative to the Creation of an International Prize Court 1907. While differing in their precise construction, the references to ‘principles’ illustrates that early practice recognised a role for a source of international law beyond treaties and custom.

Further, early arbitral practice suggests a role for general principles in international law. For example, in the Walfish Bay Boundary case, the arbitrator was required to determine the applicable law in the proceedings due to the absence of such a provision in the compromis. In doing so, the arbitrator explained the approach taken and noted that the issues at hand ‘must be solved in conformity with the principles and positive rules of public international law, and, where they fail, in conformity with the general principles of law’. As an example of the consideration of a specific general principle, in the Pious Fund case, the Tribunal was required to consider a previous decision rendered by the Mexico-United States Mixed Claims Commission. In doing so, the Tribunal found that the principle of res judicata (Latin: ‘a matter judged’), which has its origins in domestic systems and Roman law, was applicable in international law and so governed the decision in question.

In the drafting of the PCIJ Statute, the Advisory Committee of Jurists discussed the draft of article 38, including the phrasing of what would eventually become article 38(1)(c) ICJ Statute. The original draft of article 38 proposed by the Chair of the Advisory Committee, Baron Descamps, referred to ‘the rules of international law as recognised by the legal conscience of civilized nations’. This formulation suggests a more concrete category of norms – rules – derived from domestic systems, representing a departure from some earlier references to ‘principles of justice and equity’. In their discussion of Descamps’ draft, the members of the Advisory Committee debated the role that this third source of law would play and the powers that it would grant to the Court. Positions on the nature and operation of this source differed greatly, with a primary concern being the degree of discretion that would be given to the Court to develop international law. There was opposition to the idea that the Court could take an active role in the development of new international law rules in the absence of state consent, despite Descamps himself viewing the provision as a limit on such discretion. The formulation was changed into to its final form following a proposal by Root and Phillimore at the 15th Meeting of the Advisory Committee. Throughout the discussions of the Advisory Committee, there was broad agreement that the purpose of this provision was to make available to the Court a source of applicable law that could be relied upon in the absence of any applicable treaty or customary rules. The legal nature of general principles as a source of applicable law was apparent from the outset.

D. General Principles, Rules, and other Norms

The debates of the Advisory Committee on the formulation of the general principles provision point towards a more conceptual issue: that of the normative classification of general principles. From the initial starting point that general principles are a source of applicable law, questions arise as to how exactly these norms may be used. A central issue is whether general principles, in and of themselves, can be a source of obligations in international law. Further, following from the notion that general principles typically apply in the absence of treaties and custom, there is frequently a conflation between general principles and other categories of norms or concepts in international law.

On the question of whether general principles can be a direct source of obligation, the decision by the Advisory Committee to use the term ‘principle’ in place of the original ‘rule’ could suggest that general principles are different kind of norm, distinct from concrete rules of law. Indeed, there are authors who argue that general principles are broader and vaguer norms that do not impose direct obligations by provide a more general framework for the interpretation and application of rules and discretion to judges. In a similar vein, some would argue that general principles have natural law overtones and links to broader values or moral considerations. Conversely, some authors would argue that general principles, like the other sources of law, are capable of granting rights and imposing obligations. There are others, still, that view general principles as some sort of in-between; as a type of transitory norms between values and concrete rules or as a form of ‘inchoate custom’. Despite these contrasting positions, it seems clear that international courts and tribunals view themselves as being capable of recognising rights and obligations beyond treaties and customary law. A prominent example of this is the development of many procedural rules of international law, which courts and tribunals have frequently recognised as general principles owing to their presence in domestic law and foundation in certain established ‘legal maxims’.

Advanced: Rules and Principles in International Law

International lawyers will frequently debate whether something is actually part of international law; that is, whether it is a legal norm that regulates a given situation or dispute. In doing so, they deploy a range of terms to help delineate the different kinds of norms at play. ‘Rules’ and ‘principle’ are two of the most common such terms. While these terms may mean slightly different things to different people, and indeed the Court saw no relevance to the terminology at all in Gulf of Maine, these terms can be used to draw a distinction between concrete norms that impose rights and obligations (rules) and those that underlie the system and influence the interpretation of rules (principles). If such a distinction is accepted, it may be more accurate to describe general principles in the sense of article 38(1)(c) as a category of rules of international law.

As a category of norms of general international law, it can be a challenge to demarcate general principles from custom, as well as from jus cogens (Latin: 'peremptory norms') and other notions, such as values, equity, and justice. The distinction between general principles and custom can be particularly difficult to draw. Both are unwritten sources of (typically) general application. Further, it seems perfectly possible that there could exist customary rules and general principles that have similar or identical content, as has been recognised in the case of treaty and customary rules. Indeed, the ILC confirms this in its draft conclusion 11 on general principles, which reads:

1. General principles of law, as a source of international law, are not in a hierarchical relationship with treaties and customary international law.

2. A general principle of law may exist in parallel with a rule of the same or similar content in a treaty or customary international law.

3. Any conflict between a general principle of law and a rule in a treaty or customary international law is to be resolved by applying the generally accepted techniques of interpretation and conflict resolution in international law.

It has been suggested that general principles could have a supportive relationship to customary rules, aiding in their formation and interpretation. Yet, there are key differences in both the ascertainment and functions of custom and general principles. While custom is anchored in the practice and views of states, the formation of general principles involves a more pronounced role for courts and tribunals in the examination of domestic systems and notions of legal logic.

As for jus cogens, it was acknowledged by the Special Rapporteur on the topic that the reference to ‘general international law’ in article 53 VCLT includes general principles in the sense of article 38(1)(c) ICJ Statute. Indeed, the ILC expressed support for the idea that general principles of law could attain jus cogens status. Given the nature of established jus cogens norms as clear prohibitions on certain conduct, this could be seen as further evidence that general principles are a source of concrete rights and obligations. While there may be a relationship between general principles and the notion of jus cogens, it should be noted that the label ‘jus cogens’ denotes a certain elevated status that can be assigned to a norm, regardless of its source, and not a source of law in and of itself.

Finally, it seems that there is a close relationship between general principles and notions such as equity, justice, and the values of the international community. It is commonly recognised that there exist certain basic values upon which the international legal system is built, such peace and security, respect for human rights and humanity, and sustainable development. These broad values, it has been argued, may lead to the creation of general principles of law. There appears to be a significant degree of interaction between general principles and the broader values of the international legal system. Indeed, it seems logical that support for a general principle may be evidenced by its consonance with the basic objectives of the system as a whole and with fundamental ideas of legal logic.

E. Identifying General Principles

Turning now to the more practical question of how to identify a general principle. The text of the ICJ Statute itself provides little guidance on this matter. It is broadly agreed that the term ‘civilized nations’ should be discarded. Indeed, the ILC has confirmed that the phrasing ‘is anachronistic and should no longer be employed. In today’s world, all nations must be considered to be civilized.’ Going further, in a Separate Opinion in North Sea Continental Shelf, Judge Ammoun asserted that the term “is incompatible with […] the United Nations Charter”. Once the term ‘civilised nations’ is discarded, we are left with the requirement that a prospective general principle must be ‘recognised’. From this rather unhelpful starting point, two issues arise: (1) whose recognition is relevant? and (2) how can it be determined that there is sufficient recognition of a general principle?

I. Recognition by ‘the community of nations’

The issue of whose recognition is relevant for the identification of a general principles touches upon a fundamental question in international law, namely: is the creation of international law solely the prerogative of states? Indeed, traditionally, international law concerned solely states. It was states that were seen as the only participants in international law, becoming bound by an international rule only when they had given their consent to it. The ILC seemed to stay broadly in line with this position with its second draft conclusion, which reads: ‘For a general principle of law to exist, it must be recognized by the community of nations’. Before settling on the formulation “community of nations”, the ILC considered a number of terms, including “international community” and “international community of States”. The Commission explained that it adopted this phrase because of its use in article 15(2) of the ICCPR, which, because of the widespread membership of this treaty, signifies broad acceptance of this terminology. How this term will be interpreted and what significance will be attached to it is yet to be seen, but it is clear that this formulation seeks to maintain the position of states as central actors in the creation of international law.

Advanced: A Prominent Role for Courts and Tribunals?

Many accounts of general principles put courts and tribunals at the centre of their identification. As will be seen in the work of the ILC, the assessment of a prospective general principle involved the consideration of a broad range of potential pieces of evidence, from domestic law, to international instruments, to basic notions of legal logic and the foundations of the international legal system. In practice, it would seem that it would be for courts and trentals to make conduct this analysis. While it may be that many of these pieces of evidence can be traced back to states, it could be legitimately questioned whether it is not international courts and tribunals that (will) do much of the heavy lifting when it comes to the ascertainment of general principles of law.

II. Methodology for the Recognition of General Principles

Many of the ILC draft conclusions on general principles are concerned with the approach to be taken when identifying these norms. The approach set out by the Commission is predicated on an initial distinction between two categories of norms. According to draft conclusion 3, ‘General principles of law comprise those: (a) that are derived from national legal systems; (b) that may be formed within the international legal system’. This distinction between general principles derived from domestic law and those that develop on the international level is consonant with previous accounts of general principles of law, and the ILC differentiates between the approaches to the ascertainment of each of these categories.

1. General Principles Derived From National Systems

Similar to previous attempts, the ILC sets out a two-stage approach to this category of general principles. Draft conclusion 4 reads:

To determine the existence and content of a general principle of law derived from national legal systems, it is necessary to ascertain:

(a) the existence of a principle common to the various legal systems of the world; and

(b) its transposition to the international legal system.

The first of these steps is anchored in the idea that comparative law serves as a foundation for the ascertainment of general principles in international law. With such a requirement, issues arise as to the scope and content of such an analysis. The ILC seeks to provide some guidance on this in the next draft conclusion, which explains that:

1. To determine the existence of a principle common to the various legal systems of the world, a comparative analysis of national legal systems is required.

2. The comparative analysis must be wide and representative, including the different regions of the world.

3. The comparative analysis includes an assessment of national laws and decisions of national courts, and other relevant materials.

In its explanation of this draft conclusion, the Commission explains that the comparative assessment need not involve the examination of every legal system of the world. Instead, the ILC proposed a more ‘pragmatic’ approach involving consideration of a representative sample of both the ‘different legal families and the regions’ of the world. Indeed, such an approach would be a welcome departure from the practice of courts and tribunals when engaging in comparative law, as there has typically been reliance on just a handful of predominantly European legal systems. It is of course crucial that a norm of general application find broad support in a range of legal traditions and different parts of the world.

Following the ILC’s approach, it is not sufficient to merely identify a norm common to domestic legal systems. Indeed, as was noted in the South West Africa Advisory Opinion, rules of domestic law are not transposed ‘lock, stock and barrel, ready-made and fully equipped’ into international law. Therefore, there is an additional step of transposition into international law. According to the ILC, ‘[a] principle common to the various legal systems of the world may be transposed to the international legal system in so far as it is compatible with that system’. In order to determine this compatibility, the Commission sets out that a prospective general principle must be compatible with the fundamental principles of international law, such as sovereignty or basic principles in certain fields like law of the sea. Further, the ILC explained that it is necessary that ‘the conditions exist to allow the adequate application of the principle in the international legal system. This serves to ensure that the principle can properly serve its purpose in international law, avoiding distortions or possible abuse’. This requirement seems logical given the fundamental differences in the nature and structure of international law – as a decentralised and horizontal legal system – when compared with national systems.

2. General Principles Formed Within the International Legal System

When it comes to the identification of general principles with origins in the international legal system, the ILC states that ‘it is necessary to ascertain that the community of nations has recognised the principle as intrinsic to the international legal system’. In its Second Report, the Commission explained that a general principles may be seen as intrinsic to the international legal system if (1) it is widely recognised in treaties and other international instruments, (2) it underlies a general treaty or customary rule, or (3) it is inherent in the basic features and fundamental requirements of the international legal system. The first two of these indicate a close relationship between general principles and the other sources listed in article 38 ICJ Statute, suggesting that the repeated reference to a norm in treaty law or custom can in turn create a general principle. As for the final alternative, the ILC provided examples such as uti possidetis juris (Latin: ‘as you possess under law’) or the requirement that states consent to jurisdiction.

As can be seen from the work of the ILC, evidence for the existence of a general principle can be found in a range of different instruments and other sources. Further, in its draft conclusions, the ILC specifically reiterated the role of the subsidiary means – judicial decisions and academic teachings – in the determination of general principles of both categories.

F. The Functions of General Principles

Already at the drafting stage of article 38, it was suggested that general principles would have primarily a role to play where there was no applicable treaty or customary rule. This ‘gap-filling’ function is also a prevalent feature of scholarly accounts on general principles. Indeed, in its first draft conclusion on the matter the ILC explains that ‘[g]eneral principles of law are mainly resorted to when other rules of international law do not resolve a particular issue in whole or in part’. The Commission confirmed that this ‘essential function’ of general principles was to avoid situations of non liquet (Latin: ‘it is not clear’).

In addition to this, the ILC emphasised that general principles contribute to the coherence of the international legal system, a function that has also been advanced in literature. The Commission elaborated that general principles, ‘may serve, inter alia: (a) to interpret and complement other rules of international law; (b) as a basis for primary rights and obligations, as well as a basis for secondary and procedural rules’. The first of these functions seems to follow logically from the references to the links between general principles and the other sources of law in the context of ascertainment. In this regard, the ILC makes explicit reference to the rules of systemic interpretation referred to in article 31(3)(c) VCLT, confirming that this provision’s reference to ‘rules of international law’ includes general principles. Finally, the ILC’s confirmation that general principles can form a basis for both primary and secondary rules is consonant with the aforementioned legal nature of general principles as source of international law. It should be noted that it is in the development of secondary procedural rules that general principles have been identified as the most relevant. Scholarly accounts of general principles couple them with ‘international due process’ and ‘procedural’ norms, and international practice confirms that courts and tribunals most frequently make reference to general principles when attempting to answer a procedural question not covered by treaty or customary rule.

Example for Pushing the Boundaries of International Law – Judge Cançado Trindade: The recognition that general principles can serve as a basis of primary rules indicates significant potential for general principles as a means to expand and modernise the international legal system. If courts and tribunals, particularly the ICJ, embrace this function, it could be that general principles of law serve as a basis of rights and obligations where treaty law and custom do not. The late Judge Antonio Augusto Cançado Trindade was a prominent advocate for such a rule of general principles, explaining that these norms could serve as a basis for the progressive development of international law to meet contemporary global challenges such as climate change and the protection of human rights.

G. Conclusion

This chapter has provided an overview of the basic conceptual aspects of general principles as a source of international law, in light of ongoing debates about their place in the international legal system. It is clear that general principles are a recognised source of international law and that there are many potential instruments and concepts that can be consulting during their ascertainment. It remains to be seen what exactly the full potential of these norms will be, but there is scope for greater reliance on general principles to enhance the functioning of the international legal system as a whole.

Summary

• General principles of law are recognised, alongside treaties and customary law, as a source in article 38(1)(c) ICJ Statute.
• The debate on general principles has intensified since being included on the ILC’s programme of work in 2017. The ILC has produced three reports and a set of draft conclusions on general principles.
• It is commonly argued that there is a distinction between general principles that arise from domestic law and those that emerge in the international legal system. The ILC proposes a different approach to ascertainment for these two categories.
• The principal and established function of general principles is to fill gaps in the law left by treaties and custom. Other functions, include fostering coherence in international law and developing (primarily) procedural rules of law.

Further Reading

• M Andenas, M Fitzmaurice, A Tanzi and J Wouters (eds), General Principles and the Coherence of International Law (Leiden: Brill/Nijhoff, 2019).
• B Cheng, General Principles of Law as Applied by International Courts and Tribunals (Cambridge: CUP, 1953).
• C Eggett, “The Role of Principles and General Principles in the ‘Constitutional Processes’ of International Law” (2019) 66(2) Netherlands International Law Review 197.
• I Saunders, General Principles as a Source of International Law: Article 38(1)(c) of the Statute of the International Court of Justice (Oxford: Hart, 2021).