Hence every form of pedagogic naturalism which in any way excludes or weakens supernatural Christian formation in the teaching of youth, is false. Every method of education founded, wholly or in part, on the denial or forgetfulness of original sin and of grace, and relying on the sole powers of human nature, is unsound. Such, generally speaking, are those modern systems bearing various names which appeal to a pretended self-government and unrestrained freedom on the part of the child, and which diminish or even suppress the teacher's authority and action, attributing to the child an exclusive primacy of initiative, and an activity independent of any higher law, natural or divine, in the work of his education. (Papal Encyclical, Rappresentanti in Terra, 31 December 1929).