Dov Jacobs is the Senior Editor for Expert Blogging at the Leiden Journal of International Law and Assistant Professor of International Law at Leiden University] This post is part of the Leiden Journal of International Law Vol 25-2 symposium. Other posts in this series can be found in the related posts below. In the next couple of days, this second LJIL Symposium brings to you two exchanges on articles published in Vol 25(2) of the Leiden Journal of International Law, on Climate Change and Legal Pluralism. As recent discussions on Opinio Juris show, these are topical issues and we hope that the following few days will contribute to the fruitful debate on these topics. The first discussion revolves around Against Fairness? International Environmental Law, Disciplinary Bias, and Pareto Justice, the thought-provoking article by Mario Prost and Alejandra Torres Camprubi, with responses from Karin Mickelson and Eric Posner. While this constitutes the introduction to our symposium on Fairness in International Environmental Law (IEL), both authors raise issues that touch upon a number of considerations that are most relevant for international law in general. For one, they challenge the linguistic, and therefore ideological, biases of their colleagues. The rhetoric of progress and heroism that is in fact a mask on a patronizing view of the ‘other’, the ‘weak’ or the ‘victim’ is not specific to IEL. The fields of Human Rights and International Criminal Law are fueled in large part by such discourses and Manichean dichotomies of “good” Vs “evil”. The same is true of International Investment Law, which is structured by similar narratives on the greedy investor and the weak state representing the general public interest. It is therefore refreshing to see such self-reflection from the authors. Second of all, they discuss the role of fairness in IEL, specifically targeting its explicit exclusion by, among others, Eric Posner and David Weisbach in Climate Change Justice. Again, the question of what ‘fairness’ means as a philosophical and ethical concept, but most importantly its relevance as a legal norm, cuts across a number of fields of international law. The debate between the authors and Eric Posner illustrates the difficulty of approaching this issue. Indeed, while I agree with Prost and Camprubi that Posner, under the guise of pragmatism, is actually arguing another version of fairness, I would say that the substantial disagreement between them actually in itself proves Posner’s point. Because ‘fairness’ is not a monolithic concept in such a pluralist world, it will only be a relevant legal concept if some agreement can be reached on its content beforehand. Which brings us to our second discussion, relating to The Limits of Pluralism, the thoughtful Review Essay by Tom de Boer of Nico Krisch’s Beyond Constitutionalism, the Pluralist Structure of Postnational Law. We are delighted that Nico Krisch himself, as well as Daniel Halberstam, two eminent participants in this debate, have accepted to contribute to the symposium.