This chapter provides a definition of the contested concept of the rule of law and suggests that it consists of three components: legal supremacy, legal equality and legal certainty. The chapter further argues that the classical Athenian legal system valued all three components of this definition of the rule of law, but also sought to balance the good of legal certainty against a more context specific assessment of equity in particular cases. In making this compromise, the chapter suggests, the Athenians anticipated a tension that continues to exist even in modern legal systems.