ABSTRACT
This chapter explores the role played by logic in the legal domain. In legal history the Master System conception is naturally associated with the various codification movements, as well as with their successes and their failures. It is also associated with the rationalistic natural law school of the eighteenth century. The Master System conception has been designed to give satisfaction to the political ideals of security and formal equality, but it cannot guarantee other ideals, such as justice and equity. The interpretations of the Master Book should be empirical. The meanings attached to its linguistic elements must include reference to concrete situations of everyday life. Systemic problems (normative incompleteness and inconsistency) as well as linguistic indeterminacies (ambiguity, defeasibility and vagueness) make the use of evaluative considerations necessary in adjudication. It is clear that the objective and the subjective arguments may ground different and incompatible interpretations. Moreover, the same is the case with all interpretative arguments.
