We international legal scholars perceive the world as being growingly complex and intricate. Much of that perception, of course, can be traced back to the fact that our binary legal categories do not fit the world as we have come to see it. It is this very perception that has brought many of us to devise a wide range of innovative approaches to save international law from irrelevance, among them being constitutionalism, global administrative law, new legal realism, legal pluralism, and so on. It is against this backdrop that the question with which this panel grapples should be understood: Could international legal positivism (ILP) constitute a useful tool to approach and understand what we perceive as a growing complexity of this world?
I acknowledge that in the land where legal realism was born, such argument might sound either provocative or naively backward, especially since legal positivism-bashing has become an argumentative convention in our professional community, as well as a starting point of many of our scholarly inquiries. Indeed, very often ILP is seen as the very source of our inability to capture and cognize the complexity of the world. This epistemic prejudice toward ILP is what, in my view, has prevented us from seriously addressing the question of what we can expect from legal positivism in our attempts to comprehend and capture the problems of the complex world we live in.
To that question, my answer is three-fold. First, it is a qualified yes: we need positivism, but only to the extent that it is assigned a few very limited functions. This is the idea of reductionism. Second, positivism should be stripped of all the straw men that are commonly attached to it: voluntarism, state-centricism, rigid and static theories of sources, theories of interpretation and techniques of content determination, etc. This is the idea of emancipation. Third, if restricted to one particular function and emancipated from such approximations, legal positivism can prove to be a useful approach to international law that complements--and can be complemented by--other existing approaches, and which, in that sense, does not claim any monopoly on the cognition of international law. This is the idea of ecumenism. Reductionism, emancipation, and ecumenism are the three prerequisites without which it is not possible to make sense of ILP at all, and short of which ILP cannot make sense of our complex world. They simultaneously constitute three steps that ought to be taken in order to move away from the straightjacket of classical legal positivism. I will say a few words about each of them.
I advocate a reductionist understanding of ILP construed as a theory of identification of international legal rules based on a theory of sources. ILP proves most useful, in my view, if restricted to a theory of legal rules. In that sense, ILP should be geared toward providing criteria of determination of the pedigree of rules, i.e., the membership of norms to the legal system. Nothing less and nothing more. This means that ILP does not claim to provide a tool for the cognition of all international law, but just one aspect: ascertainment. That also means that ILP should not make a claim for authoritative determination of the content of rules and should not encapsulate a theory of interpretation.
Such a reductionism is not unprecedented. Unsurprisingly, I owe such a reductionist take on legal positivism to Hart (even though the argument could be made that the New Zealander John Williams Salmond, before him, had advocated such a social-fact approach to jurisprudence). It would be of no avail to discuss Hart here. I only deem it relevant to highlight one single point. Despite Hart's oversimplified reading of international law, a Hartian perspective is relevant for the very reason that it helps us restrict ILP to a mechanism of determination of the mode of existence of norms--that is, validity. …