The essay discusses the character of transnational legal expertise as a practice of making and unmaking of conceptual distinctions and moving between principles that reflect different institutionally embedded legal projects. At the same time, lawyers are trained also to carry out rhetorical performances that create the impression that these countervailing legalities may be stabilized through techniques of balancing. As a consequence, the transnational legal space appears both as a field of struggle and professional solidarity. Even as lawyers regard this as nothing other than a natural feature of the casuistry of the law itself, it alienates lay audiences that have drawn from lawyers’ constant disagreement the conclusion that legal expertise is just a species of elite opinion.

Law is an intensely historical practice. From Bodin to Savigny, from the veneration they have felt for the ‘ancient constitution’ at home to the energy with which they have embraced modernity and progress, lawyers have enlisted history to assist the power of what they have wanted to say. Law is, it sometimes feels (and is often said), precisely about the authority of the past over the present. This is true of international law as well. Working as a diplomat-lawyer, it often seemed to me that the professional service I was expected to render was to operate as the foreign ministry’s historical archive. Political decision-makers tended to feel that the situations they were faced with were new and unprecedented. The lawyers were to assist them by showing what ‘we’ did in analogous cases five, fifteen or fifty years ago. The decision then frequently came about as ‘Well, let’s do now what we did then’. There is a definite conservative wisdom in such practice. People have expectations about behaviour, based on the past, and it is often a good idea not to fail them. Indeed, much of (international) legal practice is about trying to figure out what those expectations are. In preparing a case in the International Court of Justice, counsel of the parties spend an inordinate amount of time in the archives so as to find out what agreements, understandings or patterns of behaviour may have emerged. Past facts and texts are collected into some narrative that pretends to authority, at least better authority than the story of the adversary.

It would be difficult to find a major figure in the history of European political thought who would not have attempted to say something about how authority emerges, or is justified and critiqued, in the world beyond the single polity. Quite frequently, that effort would have involved some idea about a legal order, or at least a set of rules or regularities applicable in that world. Thomas Hobbes was neither the first nor the last major thinker who believed that the ‘international’ realm was characterised by the independence of states existing ‘in the state and posture of gladiators’, thus apparently denying that legal rules or practices or legal thinking could have much relevance therein. Yet others believed, as Immanuel Kant did, that without a constitutional vocabulary not much that was meaningful could be said about the human pursuit of freedom, and that silence about the latter would not only constitute a moral failure but an intellectual and perhaps political mistake. For a long time, the idiom of natural law claimed to offer a universally valid frame for thinking about the nature of the political, as well as providing authority for lawyers’ speculations about the rules and principles governing the conduct of individuals and corporate bodies wherever they might move. The name of the relevant discipline at German universities from the late seventeenth century onwards – ius naturae et gentium, the law of nature and of nations – revealed the full scope of its ambition. That discipline may have died away (although that is a debatable proposition) but any political thinking worth its salt will today (perhaps especially in the twenty-first century) aim to say something about how authority emerges, is maintained or critiqued not only within but also outside the single state. The world of ‘nations’ or even ‘humanity’ is established as an important theme of political and legal speculation.

“… the organs are also prolongations of the tools”. According to one view, language works as an instrument for human intentions, including the imagining in which we engage in our lives. In this book I have taken the opposite to that perhaps commonsensical view, namely that the language we have determines for us the experience we have of the world, and in particular what alternatives for action we perceive therein. I have not adopted this view as a philosophical dictum. Like most such large dicta, I find it in the end too strong to be fully believable, even paradoxical. But in my life as an international lawyer, I have learned to rely on it as a very good rule of thumb when trying to understand the complexities of the governance of the international world. Why do well-educated professional women and men think and act the way they do? The technical or scientific language we have learned to master – law, development, human rights, security, environment, and so on – provides us both with an interpretation of the world as well as a recipe for dealing with its problems. Indeed, it outlines for us what those “problems” are in the first place. Having learned those languages, we attain positions of authority from which to tell people whom we address what they ought to believe or do. Professional languages have authority, and employing them we ourselves become authoritative, we become their prolongation. That is both an appealing and a problematic position in which to be. To exercise authority, we must adopt an authoritative language. But in immersing ourselves in that language, we lose critical distance from it.

The emergence of the English state in the 16th and 17th centuries was underwritten by two rival legal vocabularies: royal prerogative and the common law. These opened the two avenues through which successive Tudor and Stuart rulers tried to integrate the landowning nobility and the merchant elites in support of the crown’s policies. Each vocabulary had its biases. Prerogative powers were articulated by civilians whose Roman law training made them almost automatic supporters of absolutism. Common lawyers, by contrast, stressed the inviolability of the rights of property against the extractions of the king. Both idioms had their view also on the law of nations. Civilians focused on diplomacy and the rules of war and peace while common lawyers understood property as a natural right to wage commerce across the world. Sometimes the vocabularies came together as a specific lex mercatoria. A series of legal cases in the 17th century juxtaposed sovereignty and property rights in a way that inspired Thomas Hobbes to produce his powerful theory of the commonwealth as a protection/obedience pact in which all property rights were dependent on the decision of the sovereign.