The activities of International Non-Governmental Organizations give rise to multifaceted questions of legality and legitimacy. The normative position of INGOs within the 'international community' has proved to be acutely controversial, demanding a fundamental reconsideration of the concepts of the nation-state and of international organizations of all kinds. There is manifestly a crying need for a comprehensive framework against which the capacity of international law to comprehend these complex issues can be measured. This book explores contemporary approaches towards INGOs, those based on criticism of the doctrine of international legal personality as well as those adopting a functional-constitutional perspective. It engages in a stimulating and thorough interdisciplinary evaluation of the theoretical and practical potential of these theories to generate solutions for the problems produced by the exercise of unregulated authority outside the state-system. The book investigates the main concepts put forward by international lawyers within 'postmodern' discourse, among them 'global civil society', 'globalization' and 'governance', and examines their consistency with existing institutional arrangements, and the century-old attempts to standardize the status of INGOs.