The second area is related to the first. Since the Pope was dominant over the other bishops, he was also in ‘control’ of the sacraments administered by these bishops. Hence, the Gregorian Popes could now declare that the Sacraments were null when performed by simoniac and Nicolaite clergy, or forbid lay investiture. The argument was that the sacrament was impaired by the moral defects of the celebrants. Also, because the Church was one, the sacraments and rites were to be the same everywhere, hence the gradual imposition of the Roman rite everywhere in Western Christendom.