1.- Introduction: articulating Hayek’s evolutionary argument with his socialist calculation dispute I completely agree with Bruce Caldwell (Caldwell 1988b: 74-75; Caldwell 1988a) that it is precisely within the conceptual and theoretical framework of the debate on the possibility of socialist calculation that Hayek definitively breaks with the standard static equilibrium approach to the market economy and finds out that the central problem of economics is related to the complex question of social coordination. From the Hayekian standpoint, this problem cannot be solved without articulating a genuine theory about the role and the use of knowledge in society.1 This forms the hard core of what I will call the Hayekian theoretical argument. But one can find a much different kind of argument in Hayek, i.e. an evolutionary argument. I will characterize this argument as the Hayekian empirical argument. Hayek first exposed the essential elements of this genuine argument systematically in Law, Legislation and Liberty (see especially Hayek 1973). But in Hayek’s last book (Hayek 1988), socialism is still analyzed from this evolutionary standpoint , and as such socialism is considered by Hayek to be the major problem not only of economic theory but also, more globally, of Western civilization itself. In that book, published the year before the Soviet Union collapsed, Hayek showed himself to be absolutely confident that economic analysis could prove that socialism was not only a social blunder and a political failure, but above all a formidable scientific error. My reading of Hayek’s work is that this evolutionary argument has to be linked to the first one, which is of a more theoretical nature as far as economics is concerned. Indeed, while the evolutionary argument puts forward a completely different conceptual framework tightening the theoretical argument, it first of all displaces the gist of Hayek’s claim against socialism...