Family therapy can best be considered as a psychotherapeutic modality, embracing a variety of methods, each of these sustaining an array of techniques. The term modality refers to the characteristic orientation of the family therapist which underpins his therapeutic practice, i.e. an orientation towards tihe interpersonal processes and behaviours occurring between the members of a natural psycho-social system, the family, and between the family system and its environment. All family therapists share this position and indeed claim to be family therapists precisely because they subscribe to this modal orientation. However, although family therapy is young in its development compared with individual psychotherapy, its practitioners can be distinguished from one another in terms of both the methods and techniques by which they operationalise their approach to the modality. We can begin to identify the early development of 'schools' of practice, each working from what Ritterman (1977) has described as different 'pre-theoretical assumptions', as well as emphasising a somewhat different aspect of the theoretical framework supporting family therapy. Family therapy is not a homogeneous enterprise and the contributors to this book, by the different approaches they take, argue the case for a technical and theoretical ecclectism within the overall framework of a conjoint approach to psychotherapeutic intervention. Some effort to differentiate the developing methodological schools is therefore likely to be helpful in allowing practitioners to gain a more specific sense of their own identity within what otherwise can appear to be a confused and indeterminate field of practice. As Ritterman (1977, p. 29) comments, 'It is no longer sufficient to differentiate family therapy in general from other therapies. A method for distinguishing the unique contributions of the various models of family therapy is needed. '