A dialética entre regras e princípios: uma aproximação ao raciocínio jurídico

This article examines the dialectic between legal rules and principles as a way of approximating the structure of legal reasoning in contemporary constitutional states. It challenges widespread commonplaces in neo-constitutional and anti-positivist scholarship that present principles as intrinsically anti-positivist and fundamental-ly distinct from rules. Drawing on debates since the late 1960s and on the practice of principle-based adjudication, the author argues that rules and principles are not mutu-ally exclusive categories but interact at multiple levels of interpretation, justification and application. Principles inform the interpretive construction of rules, for exam-ple through teleological and constitution-conforming arguments, while rules in turn constrain and structure the concrete balancing and realization of principles. From this perspective, the apparent opposition between “law by rules” and “law by princi-ples” conceals a more complex argumentative dynamic, in which principles and rules continuously shape each other within legal reasoning. The essay thus proposes a de-mystifying analytical framework aimed at better describing, controlling and critically assessing principle-based and rule-based legal argumentation.