For false prophets have gone forth into the world,
to corrupt the minds of the faithful with various and strange doctrines, of whom the Lord has said: I did not send
prophets, yet they ran; I spoke not to them, yet they prophesied.

In this work, to such extremes has their impiety, practiced in all the arts of Satan, been carried, that it would
seem almost impossible to confine it within any bounds; and did we not rely on the splendid promises of the
Saviour, who declared that He had built His Church on so solid a foundation that the gates of hell shall not
prevail against it, we should have good reason to fear lest, beset on every side by such a host of enemies and
assailed and attacked by so many machinations, it would, in these days, fall to the ground.

For - to say nothing of those illustrious States which heretofore professed, in piety and holiness, the true
Catholic faith transmitted to them by their ancestors, but are now gone astray wandering from the paths of truth
and openly declaring that their best claims to piety are founded on a total abandonment of the faith of their
fathers - there is no region, however remote, no place, however securely guarded, no corner of Christendom,
into which this pestilence has not sought secretly to insinuate itself.

For those who intended to corrupt the minds of the faithful, knowing that they could not hold immediate
personal intercourse with all, and thus pour into their ears their poisoned doctrines, adopted another plan which
enabled them to disseminate error and impiety more easily and extensively. Besides those voluminous works by
which they sought the subversion of the Catholic faith - to guard against which (volumes) required perhaps little
labour or circumspection, since their contents were clearly heretical - they also composed innumerable smaller
books, which, veiling their errors under the semblance of piety, deceived with incredible facility the
unsuspecting minds of simple folk. 

Council of Trent 1562