In 1973 was published Posner's masterpiece, Economic Analysis of Law. The importance of this book has largely been noted and its content scrutinized. One aspect has in particular been emphasized, it was the moment when law-and-economics became a new field or, rather, when a second and radically new form of interactions between economics and the law was born. Actually, if it is exact that Posner wrote the book in a context in which economics was changing and in which some called for a change in legal studies, it is also important to recall that the book only partially achieved this and also that it was not perceived as inventing an economic analysis of law. It was perceived as a political, ideological book promoting a very specific form of economics.