Cardinal John Henry Newman wrote this book while he was deeply enmeshed in a process that would ultimately lead to his conversion to the Roman Catholic Church from the Anglican communion. In this book he deals with, among other things, the Protestant contention that every doctrine to which the church is to hold must be explicitly taught in the Bible and therefore such doctrines as purgatory, penance, the immaculate conception of Mary and her assumption, etc., are to be rejected.
Newman makes three assertions:
1. The increase and expansion of the Christian Creed and Ritual and the variations attending the process are the necessary attendants on any philosophy which takes possession of the intellect and heart. To desire to return to the early church is, in fact, a desire to return to infancy rather than maturity.
2. Time is necessary for the full comprehension and perfection of great ideas.
3. The highest and most wonderful truths could not be comprehended all at once by the recipients, who had minds not inspired and would require a longer time for thier full elucidation.
While Prostestants say that a stream is clearest near the spring, Newman asserts that this cannot be said of a philosophy or belief, which is made purer and stronger when its bed has become deep and broad and full. In fact, a stream necessarily rises out of an existing state of things and for a time savors of the soil. Its vital elements need time to disengage from what is foreign and temporary. Therfore, the development of doctrine over time is to be expected.
This is a very dense book, and for some time I have wanted to work through it. I am getting to it now and wondering if anyone knows of a significant Protestant response to Newman. If so, I would appreciate you passing it along.

