Parallel Reasoning by Ratio Legis in Contemporary Jurisprudence. Elements for a Dialogical Approach

Abstract

Nowadays, there is a quite considerable amount of literature on the use of analogy or more generally of inferences by parallel reasoning in contemporary legal reasoning and particularly so within Common Law. These studies are often motivated by research in artificial intelligence seeking to develop suitable software-support for legal reasoning. Recently, Rahman et al. (Inferences by Parallel Reasoning in Islamic Jurisprudence. Al-Shīrāzī’s Insights into the Dialectical Constitution of Meaning and Knowledge. Springer, Dordrecht, 2019) developed a dialogical approach in the framework of Constructive Type Theory to what in Islamic Jurisprudence was called qiyās or correlational inferences. In their last chapter the authors suggested that such an approach contributes to the study of patterns of reasoning by precedent cases within contemporary Common Law. In the present paper we will further motivate the deployment of the dialogical framework developed in Rahman et al. (2019) within Civil and Common Law. After a presentation of Scott Brewer’s take on analogy within Common Law, that has striking structural similarities to reasoning by precedent case rooted in ratio legis (known in Islamic Jurisprudence as qiyās al-‘illa or correlational inference by the occasioning factor), we will illustrate the implementation of the framework with a brief discussion of some cases of legal reasoning based on Spanish Civil Law but where the accent is put in the emerging ruling rather than in the existing of a case in Common Law. Moreover, quite surprisingly, the case under study suggests that even cases of Law interpretation fit the argumentation pattern of qiyās al-‘illa. A caveat: in the present paper we will focus mainly in discussing the dynamics of the meaning constitution involved rather than in setting the rules of the underlying dialogical framework, the latter is the subject of a follow-up paper.