3 But the supreme pastors of the Church, on whom the duty falls of guarding the Lord's flock from the snares of the enemy, have striven in time to ward off the danger and provide for the safety of the faithful. For, as soon as the secret societies began to be formed, in whose bosom the seeds of the errors which we have already mentioned were even then being nourished, the Roman Pontiffs Clement XII and Benedict XIV did not fail to unmask the evil counsels of the sects, and to warn the faithful of the whole globe against the ruin which would be wrought. Later on again, when a licentious sort of liberty was attributed to man by a set of men who gloried in the name of philosophers,(4) and a new right, as they call it, against the natural and divine law began to be framed and sanctioned, Pope Pius VI, of happy memory, at once exposed in public documents the guile and falsehood of their doctrines, and at the same time foretold with apostolic foresight the ruin into which the people so miserably deceived would be dragged. But, as no adequate precaution was taken to prevent their evil teachings from leading the people more and more astray, and lest they should be allowed to escape in the public statutes of States, Popes Pius VII and Leo XII condemned by anathema the secret sects,(5) and again warned society of the danger which threatened them. Finally, all have witnessed with what solemn words and great firmness and constancy of soul our glorious predecessor, Pius IX, of happy memory, both in his allocutions and in his encyclical letters addressed to the bishops of all the world, fought now against the wicked attempts of the sects, now openly by name against the pest of socialism, which was already making headway.
Source: Quod Apostolici Muneris (Vatican.va)