87. In such a school moreover, the study of the vernacular and of classical literature will do no damage to moral virtue. There the Christian teacher will imitate the bee, which takes the choicest part of the flower and leaves the rest, as St. Basil teaches in his discourse to youths on the study of the classics. Nor will this necessary caution, suggested also by the pagan Quintilian, in any way hinder the Christian teacher from gathering and turning to profit, whatever there is of real worth in the systems and methods of our modern times, mindful of the Apostle's advice: "Prove all things: hold fast that which is good." Hence in accepting the new, he will not hastily abandon the old, which the experience of centuries has found expedient and profitable. This is particularly true in the teaching of Latin, which in our days is falling more and more into disuse, because of the unreasonable rejection of methods so successfully used by that sane humanism, whose highest development was reached in the schools of the Church. These noble traditions of the past require that the youth committed to Catholic schools be fully instructed in the letters and sciences in accordance with the exigencies of the times. They also demand that the doctrine imparted be deep and solid, especially in sound philosophy, avoiding the muddled superficiality of those "who perhaps would have found the necessary, had they not gone in search of the superfluous." In this connection Christian teachers should keep in mind what Leo XIII says in a pithy sentence:In particular, I am encouraged to see his recommendations of the following: the study of Latin and classical literature, the concept of taking what is best from what we learn about education and setting aside the rest, and the importance of deep and solid teaching. Perhaps my favorite quote from this segment (worthy of Chesterton, it seems to me, but as it turns out, the Holy Father is quoting the Roman philosopher Seneca) is: "who perhaps would have found the necessary, had they not gone in search of the superfluous."
Greater stress must be laid on the employment of apt and solid methods of teaching, and, what is still more important, on bringing into full conformity with the Catholic faith, what is taught in literature, in the sciences, and above all in philosophy, on which depends in great part the right orientation of the other branches of knowledge.
Read the entire text of the encyclical here