These definitions seem to be innocent, fair-minded and straightforward. However, as we shall see, their apparent simplicity masks a host of problems which are easily revealed by asking simple questions of the following sort. What is the meaning of 'family', 'therapy', 'psychosocial', 'intervention', 'system', 'therapeutic strategy', 'impact', 'entire family structure', 'psychotherapeutic', 'understanding', 'intervention' and 'organic'? Indeed Glick and Kessler devote their excellent book to a detailed and balanced discussion of these key terms. It is clear from their account that there is in fact little agreement among the experts as to what these key terms mean. Thus the generality of their general definition is somewhat reduced.