Symposium : A Colloquium on International Law Textbooks in England, France and Germany

• Capps, P

Abstract

Within international law, theory is often considered peripheral to more pressing practical problems. In the first part of this article, it is argued that refusal to take account of theoretical and methodological issues entails that particular descriptions of international law lack validity, and, hence, rational reasons cannot be provided as to why one account should be considered preferable to any other. This problem of rational justification, which emerges in a variety of forms, is referred to as the incommensurability thesis. The argument is illustrated with respect to the ninth edition of Oppenheim's <it>International Law</it>. In part two, a methodology is advanced which demonstrates how a justifiable account of international law can be generated which avoids the incommensurability thesis. This methodology states, specifically, that international lawyers must develop (a) a coherent understanding of the kind of function international law performs in maintaining social order in the relations between states and (b) a substantive conception of social order. Therefore, in order for a particular account of international law to possess validity over rival accounts, international lawyers must take account of social theory and moral and political philosophy. The final part of this article discusses the concepts of international law offered by Weil and Kant, which can be understood as examples of the methodological approach offered in this article.