ABSTRACT: We chose as a research topic for our study one of the most important components of society and the legal order: the “norm” and we propose an interdisciplinary analysis. For this reason, we stopped at the analysis of the legal norm in the period of ancient Rome and at the connection between jus (law), lex (law, legal norm), mos (custom, morality, morav) and fas (religious norm). The structure of our paper begins with the presentation of the meaning of legal norms in Roman law, the elements of the legal norm, their significance, and the effects that a legal norm (written or unwritten) produced in the ancient Roman world. Then we continued to analyze the classification of law (jus) and the connection between ius / jus and justice, re...