25 The extent of the Church's mission in the field of education is such as to embrace every nation, without exception, according to the command of Christ: "Teach ye all nations;" and there is no power on earth that may lawfully oppose her or stand in her way. In the first place, it extends over all the Faithful, of whom she has anxious care as a tender mother. For these she has throughout the centuries created and conducted an immense number of schools and institutions in every branch of learning. As We said on a recent occasion: Right back in the far-off middle ages when there were so many (some have even said too many) monasteries, convents, churches, collegiate churches, cathedral chapters, etc., there was attached to each a home of study, of teaching, of Christian education. To these we must add all the universities, spread over every country and always by the initiative an under the protection of the Holy See and the Church. That grand spectacle, which today we see better, as it is nearer to us and more imposing because of the conditions of the age, was the spectacle of all times; and they who study and compare historical events remain astounded at what the Church has been able to do in this matter, and marvel at the manner in which she had succeeded in fulfilling her God-given mission to educate generations of men to a Christian life, producing everywhere a magnificent harvest of fruitful results. But if we wonder that the Church in all times has been able to gather about her and educate hundreds, thousands, millions of students, no less wonderful is it to bear in mind what she has done not only in the field of education, but in that also of true and genuine erudition. For, if so many treasures of culture, civilization and literature have escaped destruction, this is due to the action by which the Church, even in times long past and uncivilized, has shed so bright a light in the domain of letters, of philosophy, of art and in a special manner of architecture.
Source: Divini Illius Magistri (Vatican.va)