What determines real Christian doctrine? How have the primary tenets of Christian theology come out of biblical texts that do not explicitly provide for such conclusions? John Henry Newman wrestled with these questions for much of his adult life. In his Essay, Newman provides seven tests by which the development of an idea may be legitimized. Through this process he concludes that there has never been any innovation in Christian theology, only development and clarification to accommodate the needs of a specific era.
The quality of his literary style is so successful that it succeeds in escaping definition. The quality of his logic is that of a long but passionate patience, which waits until he has fixed all corners of an iron trap. But the quality of his moral comment on the age remains what I have said: a protest of the rationality of religion as against the increasing irrationality of mere Victorian comfort and compromise.
The philosophical and theological thought and the spirituality of Cardinal Newman, so deeply rooted in and enriched by Sacred Scripture and the teachings of the Fathers, still retain their particular originality and value.
—Pope John Paul II
Newman placed the key in our hand to build historical thought into theology, or much more, he taught us to think historically in theology and so to recognize the identity of faith in all developments.
—Joseph Cardinal Ratzinger (Pope Benedict XVI)