Idéologie et langues des calculs (S. Auroux) From a summary of the texts in which the principal ldeologists (Destutt, Garat, de Gérando, Maine de Biran) react to Condi1lac's treatise La Langue des calculs, the author attempts to show how a unanimous refusaI of the mathematization of logic led the Ideologists to adopt a position that showed down development in this feld.