The historiographical background to this paper is provided by a recent dramatic change of perspective in the study of the Reformation in Ireland. Traditionally the failure of Protestant reform has been explained in ways that amounted to determinism. In its crudest expression, this involved the self-sufficient premise that the Catholic faith was so deeply ingrained in the Irish as to be unshakable. More subtly, it assumed a set of equations, of Protestantism with English conquest and Catholicism with national resistance, that acted to consolidate the faith. In the 1970s, these simplicities were questioned. Dr Bradshaw and Dr Canny argued that religious reform had made sufficient headway in its initial phase to suggest that the replacement of Catholicism by Protestantism was at least within the bounds of possibility, and raised a fresh question; why did this not happen? That the debate which followed was inconclusive was due in part to an inability to shake off an old habit of circular thought, so that the issue has remained one of deciding whether Protestantism failed because Catholicism succeeded, or Catholicism succeeded because Protestantism failed. Both Dr Robinson-Hammerstein, when she observed that ‘Ireland is the only country in which the Counter-Reformation succeeded against the will of the Head of State’, and Dr Bottigheimer, when he insisted that the failure of the Reformation must ‘concentrate our attention on the nature and limits of political authority’, implied that what needs to be explained is how actions were deprived of their effect. The alternative possibility is that the actions themselves were inherently ineffectual. The premise of this paper is that the failure of Protestantism and the success of Catholicism were the necessary condition, but not the sufficient cause, of each other, and its object is simply to recall attention to the existence of very practical reasons why the Church of Ireland should have evolved as it did in the hundred years or so between the first and second Acts of Uniformity, that is, from an inclusive Church, claiming the allegiance of the entire community, to one that excluded all but a privileged minority.