This paper reflects on the modest role fulfilled by general principles of law in contemporary international legal thought and practice. It submits that the tepidity with which international lawyers have resorted to general principles of law in practice and legal thought — and especially in their expansionist enterprises — is the result of the inability of general principle of law to operate a source of international law. In particular, it is argued here that the miserable fate of general principles of law can be traced back to a choice by early 20th century international lawyers to locate and organize the prevention of non liquet as well as analogical reasoning within the sources of international law. The following will show that the doctrine of sources of international law may not have proved the most adequate framework for the prevention of non liquet and gap-filling function that was bestowed upon general principles of law. It is only once general principles of law come to be construed and deployed in international legal thought and practice as an argumentative technique of content-determination (i.e. a mode of interpretation) and thus not as a source of international law that they have a chance to play a meaningful role in international legal argumentation.