Although the Second Vatican Council specified that mere Episcopal consecration is the sole source of legitimacy for authority in the Church, today the idea of the «missio canonica», as a title for further powers and functions, is still strong. The need for stronger differentiation between Sacramental legitimacy and the power of jurisdiction is the first reason for the difficulty in realising unity between Papal primacy and Episcopal Ministry and therefore full Episcopal collegiality in the Catholic Church. In this regard, the Eastern Catholic Churches are an interesting example from which one discover solutions to such question.