2 The question is intrinsically very difficult and, in your country, it is bound up with greater problems. Still, We have not refused to address it, and particularly considering that it is necessarily connected with religion and the duty of Our office. For in this area of instruction also it has pleased us to impart the teachings of Christian wisdom in a way suited to the age and its ways. And it is pleasant to recall that these statements have yielded significant benefits both for individuals and for states, and that these results grow greater than expected as the days go by. These good fruits have been produced among Belgian Catholics as well, for their promptness to give support to instructions of this kind was extraordinary; still, these fruits were not as great as were justly expected, considering the special character of the country and the people. The hindrance in this case is known well enough. For, while moved by good intentions, they insist wrongly on consulting others on these matters. As a result, the many benefits they seek do not occur, and furthermore, discord among the Catholics flourishes.
Source: Permoti Nos (Vatican.va)