“With how great care and pastoral vigilance the Roman Pontiffs, our predecessors, fulfilling the duty and office committed to them by the Lord Christ Himself in the person of most Blessed Peter, Prince of the Apostles, of feeding the lambs and the sheep, have never ceased sedulously to nourish the Lord's whole flock with words of faith and with salutary doctrine, and to guard it from poisoned pastures, is thoroughly known to all, and especially to you, Venerable Brethren. And truly the same, Our Predecessors, asserters of justice, being especially anxious for the salvation of souls, had nothing ever more at heart than by their most wise Letters and Constitutions to unveil and condemn all those heresies and errors which, being adverse to our Divine Faith, to the doctrine of the Catholic Church, to purity of morals, and to the eternal salvation of men, have frequently excited violent tempests, and have miserably afflicted both Church and State. For which cause the same Our Predecessors, have, with Apostolic fortitude, constantly resisted the nefarious enterprises of wicked men, who, like raging waves of the sea foaming out their own confusion, and promising liberty whereas they are the slaves of corruption, have striven by their deceptive opinions and most pernicious writings to raze the foundations of the Catholic religion and of civil society, to remove from among men all virtue and justice, to deprave persons, and especially inexperienced youth, to lead it into the snares of error, and at length to tear it from the bosom of the Catholic Church.” Pope Pius IX, Quanta Cura, December 8, 1864