The name of Auguste Comte usually evokes a negative apriorism. Thus the two aims of this book: firstly, to show to how ill-suited today's image of positivism is to the man who founded it; secondly, to make the very warm reception positivist philosophy received a hundred and fifty years ago, from such eminent minds as Mill or Littré, more comprehensible. To do this, the author takes as a guiding thread "the law of three states", which the author of the 'Cours' always quoted as the matrix of his oeuvre and which resumes the history of humanity in the succession of three states: theological, metaphysical, then positive. After Auschwitz and Hiroshima, the reader of the 21st century has some difficulty identifying with the belief in progress that Comte shared with his peers, of which this law is an emblematic expression. That is why the states are presented here as forms of the spirit, which, as Comte was the first to admit, often cohabitate. The result is doubly advantageous. Firstly, although (partly under the influence of neo-positivism) positivism has become a philosophy of science alone, it becomes possible to make room for positivist politics and to show how, in Comte's project, political and scientific philosophies call out to each other. Moreover, a presentation in two phases allows the author to separate the aspects of Comte's thinking that correspond more or less to the familiar image, and those which, even today, still seem extravagant; they are far from being the least interesting.
