This thesis is a study of the role of written texts in processes of identity construction and maintenance in a Catholic parish community. It is based on a critical realist understanding of society which sees social practice as the locus of continuity and change and requires detailed observation of social activity explained within a theoretical framework to achieve an understanding of the mechanisms at work in society. Social practice is understood as "habitualised ways, tied to particular times and places, in which people apply resources (material or symbolic) to act together in the world" (Chouliaraki and Fairclough 1999: 21). Social practices are drawn on and continued in social activity, a process which articulates four moments: material activity, social relations and processes, mental phenomena, and meaning-making processes. These moments are not understood as being discrete but rather as existing in dialectical relations of reciprocal intemalisation. Language and literacy are analysed in terms of their embeddedness within this model of social practice. Identity is conceived of as particular ways of being which are realised in social activity as people engage in particular social practices. Within this framework, the study analyses data consisting of written texts and fieldnotes describing the practices within which those texts were embedded, which was collected during a year's participation-observation in three domains of a Catholic parish community, using a grounded approach. Three concepts are developed to explain the role of text in each of these domains: recontextualisation of identity, negotiated legitimation, and synchronisation of communities. These mechanisms are then explained in terms of the social contexts within which they are situated. Finally, the role of these mechanisms within social practice is analysed. It is argued that in each of them, the crucial role of written text is to provide an intertextual means by which relational links can be made between different communities and different elements of individuals' identities.