These Christians recognize — and Catholics acknowledge — that not all the Church’s teachings are explicitly found in Scripture or the preaching of the early Fathers.
Some doctrines were not stated fully and clearly until much later in the life of the Church.
The second note of genuine development is continuity of principles.
Newman insists that for a development to be faithful, it must preserve the principle with which it started.
If so, we know that the change is a genuine development, not a corruption.
Newman warns that the presence of any alteration in the external expression of an idea shouldn’t lead us to conclude that it’s a corruption, instead of a development, of the essential idea.In Newman’s terminology, then, when we make use of these re-sources we are assimilating them.The food, water and air we consume don’t change who or what we are in any meaningful way.Our Protestant brothers and sisters often wonder at the complexity of Catholic doctrine.In particular, they may find it difficult to reconcile what they view as the “simplicity” of Jesus’ teachings with those of the Church today.As a result, many Protestants conclude that Catholic teaching is a corruption of the original Gospel message.Catholics, on the other hand, see the doctrines of the Church as the necessary and logical development of the Gospel.While doctrine may grow and develop, principles are permanent.Newman identifies the Incarnation as the fundamental truth of the Gospel.In fact, in the process of assimilation it’s the external realities themselves that are transformed (once they are assimilated), not the doctrine.In Newman’s view, the more powerful, independent and vigorous the idea, the greater its power to assimilate external ideas and concepts without losing its identity.