I begin by saying that I am extremely grateful to the contributors to this book symposium for kindly having taken the time to read my book The Evolutionary Interpretation of Treaties, and to commit to writing their very stimulating views of it. Given the richness of the comments provided by my colleagues, it would I think be impertinent for me to do more, at this stage, than to try to set out the reflections that their comments have prompted with me.
In writing my book, one of the things I tried to do was to stress the striking interpretative potential with which the Vienna Convention rules are pregnant. It is worth remembering that when counsel for the United Kingdom in what Lord Hoffmann in Matthews  UKHL 4 at  referred to as ‘the great case of Golder’ tried to reign in the European Court of Human Rights, they did so by exhorting the Court that it was bound by the rules set out in Articles 31–33 of the Vienna Convention. It is safe to say that the strategy backfired.
The European Court was all too willing to rely on the Vienna rules, as they provided the Court with a roadmap to finding, by reliance on the principle of effectiveness to which the Vienna rules give expression, that if you claimed, under Article 6(1) ECHR, on arguable grounds to have a civil right, you had a right to have that question determined by a court. Ironically, in Golder, the former member of the ILC and international law generalist par excellence Judge Fitzmaurice felt bound in his dissenting opinion to refer to the Vienna rules as ‘factors external to’ the European Convention which had ‘little or no direct bearing on the precise point of interpretation involved’, ‘other than useful as straws to clutch at’: Golder v United Kingdom Dissenting Opinion Judge Fitzmaurice at .
Fitzmaurice’s vehement protest to the European Court’s reliance on the Vienna rules speaks to the, in the broad sense, evolutionary potential contained in the establishment of the objectivized intention of the parties through the reliance on interpretation in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose.
It is worth remembering in this connection that, as Judge Jessup observed in South West Africa (Second Phase) (Judgment)  ICJ Rep 6, 373, although many take a cynical approach to the signing of international conventions, sometimes ‘great charters of human liberties [are] signed and ratified and [become] binding on States’. It may be that, in such situations, it would be entirely wrong to think, as droits-de-l’hommistes sometimes do, that in treaty interpretation we should resist calls for establishing what the law of treaties calls the intentions of those parties. As cases such as Golder shows, nothing could be more emancipatory in such cases than insisting on straightforward application of the most traditional doctrines of treaty interpretation. Similarly, as I try to show in Chapter 5 of my book, had the European Court of Human Rights in the difficult cases on jurisdiction ratione temporis, such as Silih and Janowiec, simply applied the most traditional doctrines developed by the Permanent Court of International Justice and its successor, it would have been bound to reach a more radical result than it actually did, and a much more coherent one too.
The valuable point has been raised that my book ought to take a more theoretical approach to the topic of the evolutionary interpretation of treaties.
One such theoretical perspective that I considered taking whilst undertaking the research of which the book is the product is that of discourse analysis as a means of understanding the relation between legal knowledge and power. In order to understand the connection between knowledge and power, a concept which might be thought to have special pertinence is Michel Foucault’s concept of ‘discourse’. It is, in Foucault’s words, in discourse that power and knowledge are joined together: M Foucault, The History of Sexuality I (Vintage, 1990) 100. One superficial reason why the concept might seem a useful one to international lawyers is that a discourse is what makes us believe that the borders of a phenomenon, not unlike the borders of a state, are ‘given’ and ‘natural’. Foucault, therefore, wants us to see that these borders are functions of specific ways of thinking, liable to change and evolution—not natural or universal. In this way ‘madness’ is a function of discourses, as is ‘homosexuality’ or ‘criminality’; they are not given or universal entities.
This might be a good set of tools with which to approach the conundrum of the evolutionary interpretation of treaties.
I believe such an approach to the evolutionary interpretation of treaties works well in connection with the development of social mores over time and judicial interpretation as a function of those developing mores, especially within a relatively well-defined community such as the States Members of the Council of Europe. In the interest of full disclosure, I should say at this stage that I thought such a theoretical approach to cases such as Cossey and Goodwin—two examples given by Marko Milanovic in his post—would work so well that I wrote an article bringing to bear on these cases the type of theoretical perspective that Milanovic describes: E Bjorge, ‘Sexuality Rights under the European Convention on Human Rights’ (2011) 29 Nordic Journal of Human Rights 158.
My worry in writing The Evolutionary Interpretation of Treaties, however, was that such an approach to treaty interpretation before international courts and tribunals more generally might conceivably pose a number of problems. This leads me to four reflections.
First, it could be thought that whilst such a theoretical approach would work well in connection with developing mores and questions of morals, it might work less well in connection with legal concepts regulating, say, international borders and international trade.
Secondly, there may be a problem in relation to the interpretative community with which a work on treaty interpretation across the now broad spectrum of international courts and tribunals will have to engage. In his typically thoughtful chapter in A Bianchi, D Peat, and M Windsor (eds), Interpretation in International Law (OUP, 2015), Michael Waibel argues that, due to the specialization of international law, the ‘invisible college’ of international lawyers appears to be crumbling before our eyes. In the face of such developments, it would appear to be wrong-footed to apply theories which take for granted that a community exists between the actors or between those who have a stake in an interpretative process as that process is carried out before international courts and tribunals.
I wanted instead to focus on what, in my understanding, is common and shared as between the communities; that bien common I found to be the rules of treaty interpretation as set out in the Vienna Convention. As I have argued, these rules set out to do one thing, and I made that one thing the keystone of my book.
Third, the type of book one might have ended up writing were one to take the more philosophically orientated approach to treaty interpretation would certainly have been a much more theoretical one, and much less useful to practitioners. Highlighting philosophers and theorists on the one hand and downplaying the contributions of the ILC and of the International Court on the other might have much to recommend it, but it would also mean that certain audiences would have been less likely to engage with the work. It has been stimulating to see that the book has been referred to by counsel before international courts and tribunals; that might conceivably not have been the case had I taken the rather more theoretical approach that I could have taken.
Fourthly there is a more general point to be made. In relation to the topic of international law and the passage of time, the great German international lawyer Karl Doehring once made the point that whilst legal principles cannot change the laws of nature or rebut philosophic theorems, what they can do is autonomously to frame events and juridical facts as relevant or irrelevant: K Doehring, ‘Die Wirkung des Zeitablaufs auf den Bestand völkerrechtlicher Regeln’  Max Planck Jahrbuch 70, 70–1. It is certainly possible to say that our professional vocabulary does not possess the register or the idiom that is needed really to come to grips with certain issues on which philosophers and theoreticians have something to say. But is it not, equally, possible to say that we should, as international lawyers, do our level best to make sense of the problems that arise in our field applying our own analytical tools, our own register? That way, perhaps, we arrive at legal solutions to legal problems. If, under a broader perspective, the answers are deemed to be unsatisfactory, we may, to revert to Doehring, at least have framed events and juridical facts as relevant or irrelevant; we have, in other words, at least asked the right questions.