Divini Redemptoris §71

⁷¹ To all Our children, finally, of every social rank and every nation, to every religious and lay organization in the Church, We make another and more urgent appeal for union. Many times Our paternal heart has been saddened by the divergencies - often idle in their causes, always tragic in their consequences - which array in opposing camps the sons of the same Mother Church. Thus it is that the radicals, who are not so very numerous, profiting by this discord are able to make it more acute, and end by pitting Catholics one against the other. In view of the events of the past few months, Our warning must seem superfluous. We repeat it nevertheless once more, for those who have not understood, or perhaps do not desire to understand. Those who make a practice of spreading dissension among Catholics assume a terrible responsibility before God and the Church.