2 On the other hand, we cannot remain indifferent, or at peace, in presence of events which would seem to imperil amongst Belgians the good understanding between Catholic citizens, and to divide them into opposing camps. It would be superfluous to recall here the causes and occasions of these differences, and the encouragement they have met with where it ought least to have been expected. All these details, Dear Son and Venerable Brethren, you know better than any one; and you deplore them with us, knowing perfectly that at no other epoch could the necessity of assuring and maintaining union amongst Catholics be so great as at this moment, when the enemies of the name of Christianity rage on all sides against the Church in an unanimous attack.
Source: Licet Multa (Vatican.va)