One of the chief features of the history of the church for these last three centuries has been its conflict with the religious revolution of the XVIth century, properly called Protestantism. The nature of Protestantism may be defined as the exaggerated development of personal independence, directed to the negation of the divine authority of the church, and chiefly aiming at its overthrow in the person of its supreme representative, the Pope. It is a fixed law, founded in the very nature of the church, that every serious and persistent denial of a divinely-revealed truth necessitates its vigorous defence, calls out its greater development, and ends, finally, in its dogmatic definition. The history of the church is replete with instances of this fact. One must suffice. When Arius denied the divinity of Christ, which was always held as a divinely-revealed truth, at once the doctors of the church and the faithful were aroused in its defence. A general council was called at Nice, and there this truth was defined and fixed for ever as a dogma of the Catholic faith. The law has always been, from the first Council at Jerusalem to that of the Vatican, that the negation of a revealed truth calls out its fuller development and its explicit dogmatic definition. The Council of Trent refuted and condemned the errors of Protestantism at the time of their birth, and defined the truths against which they were directed; but, for wise and sufficient reasons, abstained from touching the objective point of attack, which was, necessarily, the divine authority of the church. For there was no standing-ground whatever for a protest against the church, except in its denial. It would have been the height of absurdity to admit an authority, and that divine, and at the same time to refuse to obey its decisions. It was as well known then as to-day that the keystone of the whole structure of the church was its head. To overthrow the Papacy was to conquer the church. The supreme power of the church for a long period of years was the centre around which the battle raged between the adversaries and the champions of the faith. The denial of the Papal authority in the church necessarily occasioned its fuller development. For as long as this hostile movement was aggressive in its assaults, so long was the church constrained to strengthen her defence, and make a stricter and more detailed application of her authority in every sphere of her action, in her hierarchy, in her general discipline, and in the personal acts of her children. Every new denial was met with a new defence and a fresh application. The danger was on the side of revolt, the safety was on that of submission. The poison was an exaggerated spiritual independence, the antidote was increased obedience to a divine external authority.