Robert Alexy’s Theory of Legal Principles

This article concerns Robert Alexy’s conception of legal principles, which conception he builds on the basis of an analysis of constitutional norms. The main assumption of his conception of rights is that in this field it is necessary to use the theory of principles as the basis. He created his own theory of principles as norms which require realization to the greatest extent possible in the light of legal and actual possibilities. Consequently, he defines principles as optimisation commands, capable of different degrees of realization depending on the actual and legal possibilities. The dimension of the legal possibility depends on the contrasting principles and rules. R. Alexy treats rules and principles as reasons of different kinds. While principles are always prima facie reasons, rules are definitive reasons until an exception to them is provided for. R. Alexy claims also that the nature of principles implies the existence of the principle of proportionality in the sense that the principle of proportionality with its three “sub-principles”: adequacy, necessity and proportionality in the strict sense, logically follows from the nature of principles and can be inferred from them