Jean d’Aspremont is concerned with the effects of the Babel syndrome created by legal pluralism. He is bewildered that international scholars ‘talk past each other’: the impression that international legal scholarship has become “a cluster of different scholarly communities, each using different criteria for the ascertainment of international legal rules” (3). This is the justification for his impressive intellectual effort to present a ‘theory of the ascertainment of legal rules’ and engage in the politics of formalism (29).
His theory is rooted in Herbert Hart’s famous source and social theses, which are reinterpreted by d’Aspremont to fit international law. In d’Aspremont’s theory, “law-ascertainment in international law must be conceived independently of article 38 [of the ICJ Statute], which was not only conceived to serve another purpose, but also leaves too much room for non-formal law-ascertainment”(150). He favours the use of written linguistic indicators (formal law-ascertainment is only possible for rules enshrined in a written instrument) to guarantee formal law-ascertainment in international law and move away from intent-based systems to determine international legal rules.
D’Aspremont affirms that his proposal amounts to “a complete reversal of our theoretical perspectives which allows the ascertainment of treaties and other international legal acts to do away with the speculations inherent in the establishment of intent and makes it exclusively dependent on the use of linguistic indicators” (192). The source thesis, by which rules are ascertained through their pedigree, is completed by the social thesis, which provides the foundations for the formal law-ascertainment of rules in the social practice of law-applying authorities. That is, in a nutshell, D’Aspremont’s recipe to secure true common legal language in “an age of pluralized normativity” (221), a goal that cannot be achieved by other techniques of law identification based on impact, compliance, process, or intent.
A blog post is, of course, not the ideal medium to review in detail the many interesting points raised by d’Aspremont in his encyclopedic, often complex, but absolutely remarkable piece of scholarship. I would rather advance three interconnected comments on some of the more controversial aspects of his book.