ABSTRACTThe ‘puritan diary’ has received attention from historians and literary critics with little exchange between the approaches. Placing the diary in the context of experimental Calvinist personal discipline reveals that the form emerged independently of the literature of practical divinity. Considering the practice as a ‘technology of the self’ draws attention to the meanings of writing in a protestant context and encourages us to consider the cultural resources available to early modern protestants. Close reading of these texts suggests a greater degree of complexity than is often admitted and allows for a tension between different views of the salvific process. This tension between ‘open’ and ‘closed’ forms is helpful in understanding the religiosity of early modern protestants.