Divini Illius Magistri §86

⁸⁶ In such a school, in harmony with the Church and the Christian family, the various branches of secular learning will not enter into conflict with religious instruction to the manifest detriment of education. And if, when occasion arises, it be deemed necessary to have the students read authors propounding false doctrine, for the purpose of refuting it, this will be done after due preparation and with such an antidote of sound doctrine, that it will not only do no harm, but will an aid to the Christian formation of youth.