‘Consistency’ and ‘completeness’ are age-old concepts which are traditionally related to logic and logical calculi. They have received a great elaboration and their mutual relations have been widely studied in the field of logic. They have also been extensively analyzed by legal dogmatics and analytical jurisprudence regarding their application to normative systems.
By contrast, ‘coherence’ is a relatively new concept, which has raised some issues in the epistemological and legal philosophical debate during the last decades. The intensional properties and the boundaries of this concept are quite blurry, and its relations with consistency and completeness are consequently uncertain.
The present paper, by elaborating on some notions of propositional calculus, aims at providing a basic reexamination of the notions of consistency, completeness, and coherence, when applied to the normative domain, and, on such a basis, elaborating on which mutual relations they have.