This article refines our understanding of the fourth-century Athenian democracy by examining the extent to which the rule of law checked the power of the popular Assembly. Although the concept of the rule of law may take on various meanings in different contexts, when used in this article the phrase ‘rule of law’ refers to the idea that the Assembly should be subject to, and act in accordance with, written law. The conclusions presented in this study are based on a systematic analysis of the legal arguments delivered in graphai paranomon and graphai nomon me epitedeion theinai, which were the primary vehicles in the fourth century for enforcing the rule of law. The graphe paranomon allowed the courts to annul any Assembly decree (psephisma) that ran contrary to standing law, while the graphe nomon me epitedeion theinai permitted a similar review of new statutes (nomoi). I will argue that despite the aggressive legal reforms enacted in 403/2 BC to bring the popular Assembly under the rule of law, the rhetoric of the graphe paranomon and graphe nomon me epitedeion theinai speeches shows that these reforms were likely to have imposed only a weak restraint on the sovereignty of the Assembly. Ultimately, this study provides new grounds for concluding that the Athenian democracy of the fourth century was no less radical than that of the fifth century.