The lay magistrates' court system in England and Wales has, for centuries, permitted the detailed involvement of thousands of ordinary legally unqualified members of local communities in decisions which can have a profound effect on the lives and liberties of their fellow citizens. The role of magistrate is, therefore, important, and, for centuries, 'the great and good' monopolised local law enforcement and social control on behalf of the state. However, as this thesis suggests, the rather ad hoc, piecemeal development of the system allowed imbalances and inequalities to arise, and despite repeated efforts to reform the system in both regards, two principle criticisms remain: perceived sentencing inconsistency and social imbalance. The thesis suggests that there is a connection - denied in conventional rhetoric about criminal justice - between these two areas, a connection which is best understood via the concept of 'court traditions': habitual practices, attitudes and beliefs developed within the magistracy and, more particularly, within local benches, which allow 'non-legal' factors to influence decision-making and which perpetuate particular traditional views of the position and role of magistrates. These explanations can even utilise contradictory conceptions of the lay justice system, parading faults in one view as virtues in another. To investigate these 'traditional views', the researcher studied almost 300 lay justices and their professional colleagues at nine different English magistrates' courts. The study updates previous research about the social composition of the magistracy and - having developed a definition of 'court traditions' - examines how far this corresponds to respondents' own perceptions of the workings of the system. Attention was not only focused at the local grassroots level of lay involvement in the criminal justice system, for the researcher also studied the role of the lay justices' representative organisation, the Magistrates' Association. Possibly for the first time, the detailed working and position of this widely respected and influential group are critically discussed, and parallels are drawn between the roles of the Association and of lay justices in preserving the status quo inequalities of power and wealth of modern society