In the status passage from 'alienists' to psychiatrists, the construction of particular kinds of knowledge played a vital role. As we shall argue, medical claims to expert knowledge of madness in the second half of the nineteenth century were valuable to psychiatrists interested in professionalization because they conveyed the impression that asylum alienists were something more than 'moral entrepreneurs' to use Eliot Freidson's (1970) terms. They aspired to lay claim, in Freidson' swords, 'to knowledge of an especially esoteric, scientific, or abstract character that is markedly superior' to the claims to knowledge of 'amateurs' such as the clerical orders of the Catholic Church. The evolution of psychiatric knowledge enabled alienists to forge 'a political settlement' with the French state that guaranteed their status, material interests, and social authority in the face of persistent public criticism. As we shall see was the case with the teachers of school subjects and the associated bodies of school knowledge, so with psychiatrists and psychiatric knowledge a number of stages can be discerned in the evolutionary profile.