15 But with no less severity and sorrow have We been obliged to denounce and to put down another species of war, intestine and domestic, and all the more disastrous the more hidden it is. Waged by unnatural children, nestling in the very bosom of the Church in order to rend it in silence, this war aims more directly at the very root and the soul of the Church. They are trying to corrupt the springs of Christian life and teaching, to scatter the sacred deposit of the faith, to overthrow the foundations of the divine constitution by their contempt for all authority, pontifical as well as episcopal, to put a new form on the Church, new laws, new principles, according to the tenets of monstrous systems, in short to deface all the beauty of the Spouse of Christ for the empty glamour of a new culture, falsely called science, against which the Apostle frequently puts us on our guard: "Beware lest any man cheat you by philosophy and vain deceit, according to the traditions of men, according to the elements of the world, and not according to Christ ( Colos . ii. 8).
Source: Communium Rerum (Vatican.va)