The Macro Level: The Structural Impact of General International Law on EU Law: The Court of Justice of the EU and the Vienna Convention on the Law of Treaties
Legal uncertainty is a universal feature of primary legal materials in all legal systems. The need for judicial interpretation arises from the fact of legal certainty in legal texts. In theory, judicial interpretation is a process which should be governed and constrained by legal methodology. The law must impose methodological constraint, because in the absence of methodological constraint the judicial process would be little more than arbitrary. The judicial process in national or domestic legal systems is governed by broad criteria and traditions specific to each system, although in practice there is considerable convergence as to the various approaches judges may apply. Formally Treaty Interpretation in international law is governed by the rules of the Vienna Convention on the Law of Treaties.1 Unfortunately, however, just as legal uncertainty can never be wholly eliminated in primarily legal materials whether in statutes or in treaties there is no legal system where the accepted rules of interpretation and those governing their application are not likewise subject to legal uncertainty. Judicial discretion therefore is a fact of judicial life. The academic literature nonetheless distinguishes between courts whose interpretative approach is primarily text based and those which more liberally draw on other alternative criteria, especially teleological and policy criteria. Courts of the former type seek to minimize judicial discretion, typically ideal for cases where the text itself is ambiguous, whilst courts of the latter type expand judicial discretion beyond the sphere of textual uncertainty and seek to interpret legal instruments with reference both to the text and its underlying objects and purposes, which may be construed narrowly or more widely, and not