ABSTRACT
Recourse to concepts such as equity, fairness, justice or natural law becomes necessary in the absence of clear and precise rules of the positive law. In international law, the term equity has undergone a real renaissance. The traditional perception of the concept of equity in international law is rooted in Aristotelian thought, where equity is defined as the corrective of law. In the 19th and early 20th centuries, references to equity and the equitable powers of international arbitral tribunals appeared frequently. Equity is used as a gap filler when international law is silent. Equity against the law comes close to the traditional concept of equity in common law. Recourse to equity in traditional international law is usually distinguished from the power of courts to decide ex aequo et bono. In international environmental law, the principle of equity is both more important and more clearly defined than in general international law.
