Latin texts played a central role in the life of all religious institutions, in a way that set them apart from the laity. Monks, nuns and clergy encountered such texts daily, through the communal performance of the liturgy and other customary observances, individual devotional reading and study. Levels of knowledge and comprehension of Latin varied considerably both within and between religious institutions. Nevertheless, the concept of a textual community, as formulated by Brian Stock, accommodates the existence of differing levels of literacy within a single such community. Membership involved a shared understanding of the contents or precepts of a text or group of texts which shaped or reinforced their ideals and identity. Stock's detailed analysis focused primarily upon Continental marginal and heretical groups, but he acknowledged that textual communities also existed within the religious mainstream. England did not experience the emergence of Christian heterodox or dissident groups until the late Middle Ages, and, in all but exceptional cases, the laity's inclusion as part of a textual community required the use of the vernacular. The number of Latinate laymen was not sufficient to obviate the equation of clericus and litteratus, at a time when to be literate was understood to entail an ability to read Latin.