Over sixty years, the English presbyterians went from the party of religious intolerance, exemplified by the polemicist Thomas Edwards in the mid-1640s, to a denomination that was among the most doctrinally diverse, known in the early 1700s for exponents of religious toleration such as Edmund Calamy the younger. My primary concern, therefore, is to discover how this happened. I argue that it was not the rise of an insular, sect-type mindset among the presbyterians that enabled such a shift, but that it was provoked precisely by their dogged unwillingness to see themselves as schismatics or separatists. Instead, it was a drive towards Protestant catholicity and union with the Church of England (pursued by means of both comprehension and indulgence, often simultaneously) that paradoxically drove them towards a redefinition of both the national Church and what it meant to reform it. These radical redefinitions broke down the barriers of what it meant to be a constituent part of the Church of England, and altered the meaning of reformation such that it could be discussed almost exclusively in terms of so-called ‘moderation’ – the non-imposition of not only adiaphorous ceremonies in worship, but also any speculative doctrine which could be considered human. By 1705, those whose spiritual (and in some cases, literal) grandfathers had drafted the Westminster standards in the Jerusalem chamber, slowly began to dispense with the confession and imposition of such documents upon the church, on the basis that these were merely human formulations. This loss of confidence, appearing as it did behind the mask of the Reformation principle of sola scriptura, was combined with the presbyterian preoccupation with catholicity to form a curious cocktail of religious toleration which differed subtly from that of John Locke. The presbyterians tried hard to hold fast to a non-voluntaristic model of the Church, whilst retaining a co-extensive conception of church and commonwealth; it is from this broad view of the Church, rather than a narrow, sectarian one, that their so-called tolerationism emerges. For Calamy, it was Christian charity, expressed towards those who necessarily remained within the fold of the Church catholic, because they remained within the bounds of the commonwealth, that formed the reasonable basis of toleration, or rather, of Protestant moderation.