77 Since however the younger generations must be trained in the arts and sciences for the advantage and prosperity of civil society, and since the family of itself is unequal to this task, it was necessary to create that social institution, the school. But let it be borne in mind that this institution owes its existence to the initiative of the family and of the Church, long before it was undertaken by the State. Hence considered in its historical origin, the school is by its very nature an institution subsidiary and complementary to the family and to the Church. It follows logically and necessarily that it must not be in opposition to, but in positive accord with those other two elements, and form with them a perfect moral union, constituting one sanctuary of education, as it were, with the family and the Church. Otherwise it is doomed to fail of its purpose, and to become instead an agent of destruction.
Source: Divini Illius Magistri (Vatican.va)