Michael Foucault helped me to shape my analysis and the avoided me to use the traditional approach of the history of ideas and the history of sciences. The paralled between some of his programs of research and my own subjects made him essential to me. Thus, I integrated my study of the theme of degeneration in ninteenth century according to his interpretations about power and the cording to his interpretations about power and the process of normalization. I gave attention to his revolts which force historians to go back to work. But, I never imagined to considerer him as a matre à penser. I rather prefer to see him as a man who gives consultations and a man whose you listen to his opinions.