Within the period so called renovatio, many principles contained in the Roman legal sources have been explained in a new and innovative way, influencing the history of juridical thought and contributing to the development of the European legal experience. In fact, the principle "Rei publice interest it crimina remaneant impunita" (mentioned in two decretals of Innocent III: i.e. the Inauditum in 1199 and i.e. the Ut famae in 1203) has an essential role in the development of the conceptual system of modern criminal law. The content of this study will be, on the one hand, the detailed study of historical iter by which this principle has been consolidated and has been embraced by canonical experience and, more generally, in the Western one; on the other hand, it will analyse both from a technical and a metagiuridico point of view the origin of such formula and on the contribution that Christian theology might have given by clarifying and specifying its meaning. Therefore, it’s clear the importance of this principle in the development of the European
legal system and, broadly, in the Western legal experience.


Keywords: Criminal law; Public interest; St. Augustine; Ius commune; Juridical Trial.