The distinctive position of the Anglican communion consists in its claim to be at once Catholic while non-Roman, Reformed while non-Protestant. For the maintenance of this claim nothing is more crucial than the vindication of the reality of its Orders and Sacraments. The more the importance of the idea of the Church is re-discovered and reappreciated, the more important is seen to be the reality of the Eucharist and the Liturgy. Hence Anglicans have come to realize that if their Orders and Eucharist are open to question, their very existence as a Church becomes equally problematical.

The intervention of Pope Leo XIII in this question of the validity of Anglican Orders and the decision of his Bull Apostolicae Curae are familiar to all. Equally familiar is the fact that there are some who hold that neither the intervention nor the decision were final, either because they maintain that, in view of what some Catholic theologians themselves have said regarding the relative and practical character of the Bull, the judgment was not irreversible, or because they dispute the accuracy of the matters of fact on which the unfavourable judgment was based. In this way the majority of Anglican ecclesiastics and scholars are accustomed to contest the historical argument on which Catholics rely.