Following precedents is a requirement of human practical rationality. In law,arguments from precedents are present in all legal cultures and constitute one of the most important sources of legal norms and decisions. Here I argue in favour of a universal method to interpret and apply judge-made rules. This method is supported by discourse theory, which provides the basis for the development of specific directives aimed at rationalizing the process of reasoning from precedents in legal disputes. The ratio decidendi, which is the binding element of a case law rule, can be reconstructed with the help of a syllogistic model which reveals the normative premises referred to in the decision taken as a paradigmatic precedent. It is this ratio decidendi that is going to be applied in order to resolve the concrete problems that are going to happen in the future. But it is not enough to discover this rule, since it is necessary to take a step further and enter a discourse of justification where it is settled not only the content of such rule, but also its strength and scope, which will depend on institutional and non-institutional factors that interfere in the obligation to consider judicial precedents. In addition, it is always possible (even when there is a consensus about the validity of a judicial ruling) that some problems of application justify the inapplicability of the consequences of these rules in particular cases. This kind of problem, which is not infrequent in legal argumentation with precedents, can be overcome by the techniques of distinguishing (which involves the teleological reduction and the argument e contrario) and analogy.