The Great Error of the Modernists: For Them, There Is Nothing Unchangable

St. Pius X wrote in his encyclical Pascendi Dominici Gregis of 8 September,  1907 to his "venerable brothers", the "patriarchs, primates, archbishops, bishops and other local ordinaries, who have peace and communion with the Apostolic See” when wrote about the Modernists:

Thus then, Venerable Brethren, for the Modernists, both as authors and propagandists, there is to be nothing stable, nothing immutable in the Church. Nor indeed are they without precursors in their doctrines, for it was of these that Our Predecessor Pius IX wrote: These enemies of divine revelation extol human progress to the skies, and with rash and sacrilegious daring would have it introduced into the Catholic religion as if this religion were not the work of God but of man, or some kind of philosophical discovery susceptible of perfection by human efforts.' (Encyclical Qui pluribus, November 9, 1846)

These men are certainly to be pitied, and of them the Apostle might well say: They became vain in their thoughts. . . professing themselves to be wise they became fools (Rom. i. 21, 22); but, at the same time, they excite just indignation when they accuse the Church of torturing the texts, arranging and confusing them after its own fashion, and for the needs of its cause. In this they are accusing the Church of something for which their own conscience plainly reproaches them.”

  Link to Katholisches...