The current psychiatric classifications are of little or no use in individual diagnosis, therapy and prognosis. Besides they are not suited to map the complex field of psychiatry. This is because psychiatry lacks common definitions, common basic concepts and generally accepted models of thinking and working. Psychiatry will only succeed in constructing a valid and reliable classification of facts and states if it becomes a real science. According to Kuhn this means that psychiatrists should constitute a scientific group and that psychiatry should acquire a disciplinary matrix. Viewing the complexity of the field a consistent systems approach can play an important role in this psychiatric revolution.