Taking stock: a theory with more than half a century of history. Introduction

The revision of this book (which followed a long gestation) was undertaken during 2011, a year which saw the proliferation throughout the world of scientific events (symposia and international workshops, books (Almeida et al. 2011; Galli 2012 forthcoming), special issues of journals (Camargo and Tomanari 2011; Howarth et al. 2011 forthcoming) with the purpose of both celebrating the fiftieth anniversary of the book La Psychanalyse, son Image et son Public, that represents the official act of birth of the theory, and to pay homage to its author, Serge Moscovici, who in over sixty years of intense scientific and intellectual work has produced at least three theories which have marked the history and destiny of the social sciences: (a) the theory of social representations; (b) the theory of innovation – commonly termed ‘of active minorities’; (c) the theory of collective decisions and social consensus. These three theories are subtly linked together by his strong passion for the processes of innovation that have characterized the history of sciences.