Introduction We now shift from problems of macro-theory in the study of the family to an example of a problem of 'middle-range' theorizing. It is certainly not my intention to argue that the problem discussed in this chapter-the problem of the nature and significance of kinship in modern urban society-is the sole possible example of this level of theory. However, it is an important one and one which derives to some extent from the larger scale issues discussed in the previous chapter. It is a debate which has received full coverage in most of the texts and readers and is also one which raises important questions beyond the initial terms of reference. In its simplest terms this debate deals with the extent to which kin outside the immediate nuclear family have lost their significance in urban, industrial society. Is it at all meaningful to talk of a kinship or an extended family system in modern society? Or, conversely, is the relatively isolated conjugal family the typical family unit in modern society? This is not merely an academic debate; it has implications for many aspects of social policy including housing and urban redevelopment, the condition of old people in modern society and the re-Iocation of industry. This chapter will examine some of the arguments on either side of this debate and will attempt to provide an overall evaluation. It is not my intention to provide a comprehensive survey of the literature but, rather, to concentrate on certain representative figures in the debate. The main argument is that these studies of kinship have on the whole become divorced from major issues in the sociology of the family and that this divorce has been to the detriment of the theoretical development of the field.