BEFORE THE Munich psychiatrist Emil Kraepelin firstoutlined his concept of dementia praecox to the University Psychiatric Clinic in November 18g8, there had been no clear or useful classification of mental disorders. Other Gerlnan psychiatrists (Neumann 1883; Zeller 1844; Griesinger 1845) had argued against the existence of discrete and distinct illnesses and in favour of one comprehensive mental disorder, manifesting different forms. Such a disorder was believed to begin with depression, which could tum to elation and excitement, become a delusional illness, and eventually terminate as a dementing process. Such a view reflected the very real difficulties encountered by those specialists who were attempting to discern some pattern and order operating within the mass of undifferentiated clinical symptoms that could be recognized.