According to Foster, Puritanism represented a loose and incomplete alliance of progressive Protestants, lay and clerical, aristocratic and humble, who never decided whether they were the vanguard or the remnant. Indeed, in Foster's analysis, changes in New England Puritanism after the first decades of settlement did not indicate secularization and decline but instead were part of a pattern of change, conflict, and accomodation that had begun in England. He views the Puritans' own claims of declension as partisan propositions in an internal controversy as old as the Puritan movement itself. The result of these stresses and adaptations, he argues, was continued vitality in American Puritanism during the second half of the seventeenth century.
Foster draws insights from a broad range of souces in England and America, including sermons, diaries, spiritual autobiographies, and colony, town, and court records. Moreover, his presentation of the history of the English and American Puritan movements in tandem brings out the fatal flaws of the former as well as the modest but essential strengths of the latter.
