  Zooming out begins by accepting that mental illness almost always depends on complex interactions between diverse lower-level phenomena and tries to deal with this variety by treating disease networks as idealizations that are more or less similar to actual histories. It is a recurring theme in the history of psychiatry that the textbook expression of a disorder can be realized in individuals in different ways. Charcot (1887–88) distinguished archetypes, which are ideal types of disorder, from formes frustes, which are the imperfect forms the ideal type manifests in individual subjects. Birnbaum’s (1923) distinction between the pathogenic features of a psychosis and its pathoplastic features is similar. The former define its essential structure, and the latter express the personal circumstances of the patient.