Doctrinal Commentary on the Concluding Formula of the Professio fidei, su vatican.va.
«The fact that these doctrines may not be proposed as formally revealed, [...] in no way diminishes their definitive character, which is required at least by their intrinsic connection with revealed truth. Moreover, it cannot be excluded that at a certain point in dogmatic development, the understanding of the realities and the words of the deposit of faith can progress in the life of the Church, and the Magisterium may proclaim some of these doctrines as also dogmas of divine and catholic faith.»
