Following paper suggest an interpretation of the crucial moment of Kant's moral philosophy: namely, how is possible that opposed to all sensual and empirical inclination we decide to act morally, i.e. adopt a moral law as an single incentive of our action. It proceeds by introducing several critiques on Kant moral teaching (Schiller, Habermas etc.), which will be answered by interpretation focusing on the double role of respect in Kant's Critique of Practical Reason. It will be argued that Kant is not so pure and strict cognitivist or formalist as suggested, though the respect for moral law is not exactly the same as the notion of sublime.