The Catholic Church is "one," first in government and second in doctrine. In government every pastor has a certain parish or territory in which all the people belong to his congregation--they form his flock. He has to take care only of these, to teach them, give them the Sacraments, etc. He has not to be responsible for those outside his parish. Then over the pastor we have the bishop, who looks after a certain number of pastors; then comes the archbishop over a certain number of bishops; next comes the primate, who is head of all the archbishops in the country; and over all the primates of the world we have the Holy Father. Thus, when the Holy Father speaks to the bishops, the bishops speak to the priests, and the priests to the people. The Church is therefore one in government, like a great army spread over the world. We can go up step by step from the lowest member of the Church to the highest--the Holy Father; and from him to Our Lord Himself, who is the invisible head of all. This regular body of priests, bishops, archbishops, etc., so arranged, one superior to the other, is called the hierarchy of the Church. The Church is one also in doctrine--that is, every one of the three hundred million of Catholics in the world believes exactly the same truths. If any Catholic denies only one article of faith, though he believes all the rest, he ceases to be a Catholic, and is cut off from the Church. If, for example, you would not believe Matrimony or Holy Orders a Sacrament, or that Our Lord is present in the Holy Eucharist, you would not be a Catholic, though you believed all the other teachings of the Church. Therefore the Church is one both in government and teaching or doctrine. Now, has any other Church claiming to be Christ's Church that mark? No. The Protestant religions are not one either in government or belief. The Protestants of England have no authority over the Protestants of America, and those of America have nothing to say over those of Germany or France. So every country is independent, and they have no chief head. Neither are they one in belief. In the same country there are many kinds of Protestants--Episcopalians, Presbyterians, Methodists, etc., who do not believe the same thing. Even those who attend the same church and profess the same religion do not all believe the same. Everyone, they say, has a right to interpret the Holy Scriptures according to his own views, so they take many different meanings out of the very same words. There must be some chief person to tell the true meaning of the Holy Scriptures when there is a dispute about it; but they have no such chief, and the result is they are never done disputing.