This rupture, in fact, raises questions which go far beyond the field of history, into the whole area of the social sciences. Two aspects, which are linked, are at the heart of this debate: the very unity of this field on one hand, and the nature of interdisciplinarity on the other. Let's come back to Simiand. For Simiand, at the beginning of the century, this unity had been defined as a unity of method. He proposed that history reshape itself along the lines of the other social sciences; or, more precisely, that it become fully a social science, changing its method so as to produce, according to honiologous rules, objects of study comparable to those produced by soci ologists, economists, geographers, etc. The problem of interdisciplinarity as such was not actually raised. Simiand assumed without question the existence of a unified model of reference: "I believe that in reality, there is already considerable evidence in the very work of present-day historians, in the choice and studicd arrangements of their work, in their obvious pre- occupation with kecping up with progress in neighboring disciplines, of a tendency to substitute progressively for traditional methods a positive, objective study of human phenomena capable of being explained scientific- ally, a tendency to devote their principal effort to the conscious development of social science.