Balancing of Legal Principles and Constraint Satisfaction

Robert Alexy is one of the main advocates of the so-called Rules and Principles Theory (hereafter: RPT). According to the RPT, legal norms can be divided into legal rules and legal principles. One of the main criteria for this distinction is - Alexy argues - that legal rules are applied by means of the Subsumption Formula, while legal principles - by means of the so-called Weight Formula (hereafter: WF). The WF offers an important insight into the structure of the process of balancing in legal reasoning. Alexy's proposal leads to many doubts and questions, however. The aim of the paper is to examine the appropriateness of the WF and the problem of balancing in legal reasoning from the perspective inspired by the constraint satisfaction theory of coherence, developed by Paul Thagard. My claim is that this theory enables us to elucidate many problematic features of the WF and to recast the structure of legal balancing in more transparent and efficient manner. The existing workable algorithms designed for computing other kinds of coherence-based reasoning (for instance, explanatory reasoning or analogical reasoning), make possible to adopt the programs employing these algorithms for computation of coherence in balancing of principles. However, the analysis presented here is mainly conceptual and it has only preparatory character in relation with the possible computational implementations in the future.