There are books that one can like or dislike but definitely not ignore. Roland Portmann's Legal Personality in International Law has all the qualities to be ranked among such books. It revisits one of the oldest and most classical concepts of international law: that of international legal personality. Yet, it looks at this concept from such an innovative, original, and interesting perspective that no one interested in the fundamental categories of international law can afford to ignore it – even less so since the book is the first comprehensive treatment of the topic available in English. Moreover, the perspective it adopts is so logical and appropriate that when reading it, one can hardly stop wondering why it has taken so long for somebody to present the topic in this way.

The book makes two claims. First, it asserts that legal personality in international law could be and traditionally has been conceptualized in five distinctive ways. The five conceptions do not differ so much in their view on what legal personality means. They all more or less agree that ‘the notion . . . is used in international law to distinguish between those social actors the international legal system takes account of and those being excluded from it’ (p. 5) – independently of the concrete terms (persons, participants) used to denote the notion. The real bones of contention between the conceptions relate to how and on what grounds personality is attributed and which entities may aspire to possess it. Viewed from that angle, the book is not so much about legal personality as it is about legal persons, though the two concepts are obviously closely linked, and it is not possible to inquire into one without casting some light (or shadow) upon the other.

While the first claim is descriptive and analytical, the second, though not devoid of such elements either, is primarily of a different nature. Portmann declares that, out of the five conceptions of legal personality, only two stand on assumptions that are compatible with the general premises of current international law. Those two conceptions, or rather a combination thereof, should therefore be promoted. Description turns into prescription here, and it has to be acknowledged that, despite the ideological sympathy one may feel for his thesis, Portmann gets far less convincing in this second area. His recommendations seem to reflect more his subjective preferences than any objective trends he claims to detect. Yet, one cannot deny that, even with this caveat, there is still merit in trying to place the concept of legal personality into a broader normative context and to reflect upon the way in which this concept is, and should be, shaped by changes in international law in general.

Throughout his book, Portmann aptly manages to dissipate several myths that are often attached to international legal personality. The first myth pretends that this topic is simple and unsophisticated. Indeed, most textbooks of international law, if they discuss it at all, do not spend more than one or two pages on it;Footnote ¹ and there are very few publications (especially in English) devoted to it.Footnote ² Yet, as Portmann reveals, legal personality is a complex phenomenon that gives rise to many interesting and intricate questions. The second myth claims that the topic is uncontroversial. When pronouncing upon personality, judicial organs often proceed as if there were a well-settled and universally shared theory on what personality implies and how it is attributed. Portmann is clear in showing that such a theory is unavailable, though he himself seeks to design one.

The third myth asserts that an inquiry into legal personality is an abstract exercise devoid of practical relevance. A practitioner himself, as a collaborator of the Swiss Ministry of Foreign Affairs, Portmann knows that this is not so. He demonstrates it in four practical issue areas: those of the direct effects of international treaties on individuals, the responsibility of international organizations, the rights and duties of non-state actors under customary international law, and the law applicable to so-called state contracts. In all these areas, the practical solutions are directly determined by the theoretical assumptions towards legal personality one assumes. Tracing the contours of the areas at the outset of the book, Portmann takes care to return to them at its very end. He does so not only to confirm the plurality of outcomes to which the application of his five conceptions leads, but also to explain what these outcomes would and should be, if his two preferred conceptions were adopted.

The book consists of three parts, which are rather unbalanced in terms of their length (24, 214, and 41 pages, respectively). Part I presents the definition of ‘personality’ quoted above and introduces the five theoretical conceptions and the four practical issue areas. Part II, though primarily devoted to the five conceptions, begins with a short historical excursion into the origins of the concept of legal personality in the premodern era. Considering the publication of Vattel's textbook in 1758 as a milestone in the evolution of international law at that time, the book looks at legal personality as it existed in international law before Vattel, in his time, and after Vattel. The account, albeit interesting, is neither complete nor thorough. This, however, is not a major problem, for Portmann uses it merely to set the scene for his further analysis, which is focused on modern international law. Moreover, J. E. Nijman has meticulously traced the history of international legal personality in her 2004 monograph.Footnote ³ The two studies could even be seen as complementary. Reviewing Nijman's book, R. Kolb wrote:

Portmann's book is undoubtedly the most solid answer to this query given so far.

The major asset of Part II, and indeed of the whole book, lies in the chapters presenting the five conceptions of legal personality. These are: the states-only conception, the recognition conception, the individualistic conception, the formal conception, and the actor conception. All the chapters follow the same three-part structure. They start with a short exposition of the basic propositions of each conception. The next part explains the broader social, political, and intellectual contexts that informed these propositions and evokes the most representative international legal scholars adhering to them. The third part tracks the main manifestations of the conception in legal practice, particularly in the case law of international judicial and arbitration organs (PCIJ, ICJ, ECJ, etc.). The crucial features of the conceptions are neatly summed up in a table found on pp. 245–6.

The basic propositions of the five conceptions vary radically. The states-only conception is state-centric and voluntarist in nature. It ‘restricts the personal scope of international law to relations between states exclusively’ (p. 42), considering that the international community consists solely of states and international legal personality is thus synonymous with statehood. International law emanates from the common will of states, which are only bound by it if, and to the extent that, they expressly consent to it. The recognition conception stems from the states-only conception but modifies some of its premises; it is equally voluntarist but slightly less state-centric. States remain the primary subjects of international law, but they are not necessarily the only ones. Other entities may be endowed with legal personality, albeit in limited form, if (and only if) states recognize it. International law is still founded upon the consent of states, which now legislate both for themselves and for other actors.

The individualistic conception sees things differently. It is individual-focused and objectivist. It claims that, even at the international level, the only natural legal persons are individuals. All other entities, including states, derive their legal personality from them. International law does not stem from subjective will solely, but incorporates also some objective general principles that grant individuals certain fundamental rights and duties. The formal conception takes a rather liberal approach. There are no a priori legal persons and no a priori legal competences attached to legal personality. The system is open-ended and able to accommodate any entity addressed by international law to the extent that it is addressed. The actor conception is the only one to reject the notion of ‘persons’ altogether. It prefers to speak about ‘participants’, who, unlike persons, are allegedly defined not by the formal place assigned to them by abstract rules, but by the effective participation in the concrete authoritative decision-making process of international law. Despite a different terminology, the actor conception shares the formal conception's view that international law is open-ended and knows no a prioris, as far as participants and their roles are concerned.

It is interesting to note that, out of the five conceptions, three originated in central Europe, more specifically in Germany and Italy, in the nineteenth and twentieth centuries. Their differences mirror the debate led at the time between legal positivists favouring a strong and unified state (states-only conception: Triepel, Oppenheim, Anzilotti), sociologically oriented authors stressing the interplay between the state and society (recognition conception: Strupp, Schwarzenberger, Cavaglieri), and normativists interested in the construction of a coherent legal theory (formal conception: Kelsen). The fourth conception, the individualist one, could be added to the list as well, since it emerged in the context of a similar debate challenging the premises of legal positivism, which took place in the mid-twentieth century in France (Lauterpacht, Scelle, Krabbe). The actor conception is the only one born outside of Europe, in the intellectual milieu of the US legal realism (McDougal, Lasswell). One may wonder whether this imbalance might suggest that Europeans are more concerned with the conceptual clarity of international law than their US, or common-law, counterparts and, if this is the case, then what the current domination of common-law scholars implies for the future of international law.

Yet, the five conceptions of legal personality are not mere theoretical constructions. The cases that Portmann cites reveal that all the conceptions have been on various occasions used in legal practice. One may, moreover, note that cases in support of rival conceptions often come from the same period and sometimes even from the same organ. Thus, for instance, the PCIJ/ICJ have so far embraced at least three conceptions (states-only conception: Mavrommatis,Footnote ⁵ recognition conception: Reparation for Injuries,Footnote ⁶ formal conception: La Grand Footnote ⁷) and, with some care, elements of the other two could be found in their decisions as well (individualist conception: Nuclear Weapons?,Footnote ⁸ actor conception: Kosovo?Footnote ⁹). Portmann's synopsis also suggests that, while some conceptions are unsurprisingly more popular in certain areas of international law (individualist conception: human rights) or in certain types of conflict resolution (actor conception: arbitration) than others, the correlation is by no means inevitable.

Having presented his five conceptions, Portmann moves in Part III of his book to the critical assessment of these conceptions. More specifically, he wants to find out whether the assumptions underlying each of them are compatible with the general premises of contemporary international law. To identify these assumptions, the author resorts to four questions. He asks whether the conception views the state as a fact or a legal status, whether it makes the fulfilment of individual liberty conditional upon the existence of a state, whether it believes states may be bound by rules to which they have not consented, and whether it sees the factual ‘is’ and the normative ‘ought’ as two distinct spheres. The answers to these questions given by the five conceptions make Portmann conclude that the assumptions of the states-only, recognition, and actor conceptions ‘are discarded in contemporary international law’ (p. 248), whereas those of individualistic and formal conceptions ‘find considerable support in current international legal doctrine and practice’ (p. 248).

The book closes with a claim that ‘a frame of reference for personality in international law must combine principles of the individualistic and the formal conceptions’ (p. 271). This means that international law should be seen as an open system. There are no a priori legal persons, with the exception of individuals, to whom the presumption of the direct application of basic principles related to international crimes and fundamental human rights applies. For other entities, including states, personality follows from international norms addressing them. There are also no a priori legal consequences of personality, again with one exception, which relates to the ‘capacity to invoke responsibility and to be held responsible for international wrongful acts’ (p. 277). The other consequences are determined by norms addressing any concrete entity. To give some satisfaction to the supporters of other conceptions, the author admits that recognition ‘has considerable evidential value’ (p. 277) and the same applies to ‘effective actor status’ (p. 277).

These conclusions and, in fact, the whole of Part III of the book are not truly persuasive, nor well evidenced. They remain vulnerable to various sorts of objections, out of which two will be raised here. First, the alleged premises of contemporary international law, summarized on pp. 268–9, are identified in a way that would hardly withstand rigorous scrutiny. In fact, when ascertaining where international law stands with regard to the four questions mentioned above, Portmann does not delve into any comprehensive and meticulous analysis of recent international practice, which would be warranted in this case. Rather, he simply selects several cases, often not more than two or three, and declares them to reflect the current state of international law. While the conclusion itself may not necessarily be incorrect, the way it is evidenced is clearly insufficient. Moreover, Portmann, at times, seems to contradict himself in this context. In Part II, he spends much time showing that the five conceptions are concurrent paradigms that all manifest themselves in contemporary practice. Yet, in Part III, he suddenly claims that some of them are at odds with this very practice. In the absence of clear evidence demonstrating that some of the instances of practice are either marginal or obsolete – a claim explicitly made vis-à-vis the states-only conception solely – the contradiction is difficult to overcome.

Second, Portmann's preferred combination of the individualistic and formal conceptions seems somewhat artificial and theoretically unsound. Even if overcoming the general doubt as to whether the two conceptions, endowed with divergent underlying assumptions, can at all be safely combined, one is still left with more concrete questions relating to this particular combination. How can international law be a fully open system with no a prioris and yet accommodate such a strong presumption (hardly a rebuttable one) in favour of legal personality of individuals? Why should no automatic legal consequences be attached to legal personality except for the capacity to invoke responsibility and to be held responsible? What makes this capacity so unique and how is it expected to operate in a system whose actors are not necessarily endowed with primary rights and duties? Moreover, the way in which entities other than individuals acquire legal personality seems somewhat mysterious. This objection is directed as much against Portmann's proposal as it is, in fact, against the original formal conception. Both agree that international personality follows a posteriori from international norms addressing them. Yet, what are these norms and how are they to be identified? What does it mean to be ‘addressed’ by them? And, if there are no a priori legal persons, how did the very first norms (creating the very first legal persons) come into being? Such questions are not only theoretically interesting, but also practically relevant, and it is therefore regrettable that Portmann does not try to address them.

These critical remarks are not in any way meant to deny, or even to question, the general value of the reviewed book. Legal Personality in International Law is a piece of interesting, solid, and well-reasoned legal scholarship. Portmann has embarked upon an original and theoretically highly ambitious path. While a steady and self-confident march in the first, analytical part of the book is replaced by a less secure and slightly stumbling tramp in its second, evaluative part, the author still manages to stride through until the finishing tape. Those who decide to follow Portmann on his academic trek should have no problems keeping up with him: his marching gait is reasonable, and he sincerely endeavours not to lose anyone en route. Although one may have doubts about the direction he takes in the final part of his trek, it is still worth journeying with him to the very end – if for nothing else than to learn what obstacles lurk there, and also to observe whether, once at the post, Portmann would be awarded any medal – which, for his book, he would definitely deserve.