To think about ethical practice in social work, we first have to consider what social work is, and the impact of the environment. This chapter argues that it is fundamentally important to understand the environment in which social work operates. Further, it argues that if we are to understand our environment, and to practise ethically, we need to have an open mind, be able to critically analyse a situation, recognise a sound argument and understand the importance of a teleological approach to ethics. There is not one readily identifiable function that all social workers perform such as teaching or curing the sick. Partly it is because social work itself can be invisible. In contrast to modernity’s certainty about the world, and its use of scientific proof to test competing theories, postmodernity is a time of uncertainty, fragmentation, plurality and diversity. In social work one example is the fragmentation and increasing specialisation of social work.