The aim of the paper is to establish a relation between the cooperative principle formulated by H.P. Grice in pragmatics and the principle of sincere cooperation laid down in the founding Treaties on the European Union and interpretated by the Court of Justice of the European Union, intimately linked to the ethical imperative of cooperation, in a cultural framework shared by the Member States. The key concepts are ratio and value and the case-law analysed is provided by the recent cases (...) of the Romanian magistrates. The principle of cooperation reasserted also as the Cooperation and Verification Mechanism is the main obligation and it implies compliance with agreements and action to obtain certain effects. (shrink)