Evangelii Praecones §41

⁴¹ Since young men, and those especially who have had the advantage of a classical and liberal education, will direct the course of the future, no one can be blind to the supreme importance of devoting the best of care to elementary schools, high schools and colleges. Therefore, with paternal solicitude We exhort superiors of missions to spare neither labor nor expense in proportion to their means in vigorously promoting this phase of missionary activity.