24 Obviously the need of this Christian instruction is accentuated by the decline of our times and morals. It is even more demanded by the existence of those public schools, lacking all religion, where everything holy is ridiculed and scorned. There both teachers' lips and students' ears are inclined to godlessness. We are referring to those schools which are unjustly called neutral or lay. In reality, they are nothing more than the stronghold of the powers of darkness. You have already, Venerable Brethren, fearlessly condemned this new trick of mocking liberty especially in those countries where the rights of religion and the family have been disgracefully ignored and the voice of nature (which demands respect for the faith and innocence of youth) has been stifled. Firmly resolved to spare no effort in remedying this evil caused by those who expect others to obey them (although they refuse to obey the Supreme Master of all things themselves), We have recommended that schools of Christian doctrine be erected in those cities where it is possible. Thanks to your efforts, this work has already made good progress. It is, however, very much to be desired that this work spread even more widely, with many such religious schools established everywhere and teachers of sound doctrine and good morals provided.
Source: Editae Saepe (Vatican.va)