ABSTRACT
If a fault has developed in the smooth working of any system - whether this may be the mechanism of a car, human relations in a factory, the economic situation of a country, the ecology of some living population, a family, a marriage, or a medical or psychiatric patient - then any attempt to put it right must be based on the same fundamental principles. The first of these is that strenuous efforts must be made to identify the fault in terms of known defects or the interaction of known forces, so that any intervention can be planned and specifically based on undoing what has gone wrong. For this purpose the first step must always be the preliminary enquiry, the aims of which are to find out: (1) the exact nature of the fault; (2) how it developed; and (3) other features which may shed light on what has gone wrong and what should be done to correct it.
