At the heart of modern society and states is the concept of the rule of law as a fundamental principle. In the context of Stoicism, it is considered as a moral principle and Roman legal philosophy for removing arbitrariness from political judgments, practices, and processes. Accordingly, this article's main goal is to examine the phenomenon of modern states, which began in Europe but has since spread to many other regions of the world, in terms of the rule of law as this notion is the basis for all modern states (i.e., positive law). A comparative study is conducted in this regard in order to compare and contrast Western legal precedents such as Stoicism, Rechtsstaat [rule of law], also known as Etat de droit in French and Stato di diritto in Italian, with respect to its philosophical and historical development over time. The relevant literature was analyzed in order to determine the best method. In this framework, the study explores the notions of Rechtsstaat as the German, Etat de droit as the French, and Stato di diritto as the Italian philosophy of law.