40 This effort is necessary not only to oppose the assaults from without of those who fight openly against the liberty and the rights of the Church, but also in order to meet the dangers from within, arising from that second kind of war which We deplored above when We made mention of those misguided persons who are trying by their cunning systems to overthrow from the foundations the very constitution and essence of the Church, to stain the purity of her doctrine, and destroy her entire discipline. For even still there continues to circulate that poison which has been inoculated into many even among the clergy, and especially the young clergy, who have, as We have said, become infected by the pestilential atmosphere, in their unbridled craving for novelty which is drawing them to the abyss and drowning them.
Source: Communium Rerum (Vatican.va)