 Grice sees the principles governing conversation as derived from general principles governing human rational cooperative action. There has been much discussion about the CP and the maxims. Are all of them necessary? Do we need more? Are they normative or descriptive? What’s their exact role in the theory of implicatures: Are they principles that speakers and hearers are assumed to observe in rational communication, or simply the theorist’s tools for rational reconstruction? Does the CP require from speaker and hearer further cooperation towards a common goal beyond that of understanding and being understood? What is clear is that Grice attributes to these principles an essential role for the definition and the interpretation of conversational implicatures.