In this chapter I will be arguing that the contexts in which social work is operating are becoming increasingly complex, fluid and uncertain, and that many of the issues and problems which it is expected to address can be seen as having no easy or unambiguous solutions. As a result, the perspectives critically discussed in this volume and which draw on or are at least sympathetic towards postmodern, constructionist and reflexive perspectives, can be seen as providing crucial insights for developing critical theories for practice. More specifically, they can be seen to develop from social work's traditional strengths and understanding of social processes and where the ability to negotiate, advocate and mediate with creativity are crucial to working with the most marginalized and socially excluded members of society but where the work is becoming increasingly contested and riven with ambiguity. These perspectives provide a potentially productive set of frameworks which practitioners can draw upon in their day-to-day work. However, I will also argue that the requirements made of practitioners by central government in Britain see social workers as little more than organizational functionaries. Here, the requirements made of practitioners are increasingly modernist and rationalist, and it is assumed that the nature of practice simply requires the application of taken-for-granted and codified knowledge often in the form of a very circumscribed and limited notion of 'evidence-based practice' (EBP). The focus for my analysis will be local authority social work in England and Wales. While it is recognized that this is a very specific exemplar and that there will be important differences in other jurisdictions and in other contexts, it is also argued that developments in England and Wales are not unique. Even so, I do recognize that the position of social work in England and Wales over the last thirty years has been somewhat unique in its close association with the central and local state via the establishment and development of local authority social services departments.