The analytical argument justifying the evolution of Patinkin's position on the method employed in the General Theory leads to a severe ambiguity : the Keynésien model is supposed to express Walrasian interactions as well as Marshallian partial equilibrium. Patinkin synthétises his position by using a mysterious paraphrase of Genesis, which expresses, as we show, the predominance of the Walrasian method. Interactions are the only reason given by Patinkin to explain the connection between the Keynesian model and the Walrasian method. This paper shows that they are only a necessary condition because mis model also has important commun points with the classical tradition which separate it from Walras.