And here it seems opportune to expound and to refute a certain false opinion, on which this whole question, as well as that complex movement by which non-Catholics seek to bring about the union of the Christian churches depends. For authors who favor this view are accustomed, times almost without number, to bring forward these words of Christ: "That they all may be one.... And there shall be one fold and one shepherd,"[14] with this signification however: that Christ Jesus merely expressed a desire and prayer, which still lacks its fulfillment. For they are of the opinion that the unity of faith and government, which is a note of the one true Church of Christ, has hardly up to the present time existed, and does not to-day exist. Above stated by Pope Pius XI, Mortalium Animos, On Religious Unity, 1928.