Remembering and returning

 Ash Wednesday , where we reflect "thou art dust, and to dust thou must return" seems like a good day to think about Cardinal Newman's analogy of corruption:  

To find then what a corruption or perversion of the truth is, let us inquire what the word means, when used literally of material substances. Now it is plain, first of all, that a corruption is a word attaching to organized matters only; a stone may be crushed to powder, but it cannot be corrupted. Corruption, on the contrary, is the breaking up of life, preparatory to its termination. This resolution of a body into its component parts is the stage before its dissolution; it begins when life has reached its perfection, and it is the sequel, or rather the continuation, of that process towards perfection, being at the same time the reversal and undoing of what went before. Till this point of regression is reached, the body has a function of its own, and a direction and aim in its action, and a nature with laws; these it is now losing, and the traits and tokens of former years; and with them its vigour and powers of nutrition, of assimilation, and of self-reparation.  

It is only a living thing that can die, an organized thing that can dissolve and decay.   

I wonder if like living things, ideas when they resolve into corruption end up providing nourishment for  future true ideas?   

Newman goes on to set down "notes" of varying cogency, independence and applicability" for the determination of healthy development as opposed to corruption and decay.

—There is no corruption if it retains one and the same type, the same principles, the same organization; if its beginnings anticipate its subsequent phases, and its later phenomena protect and subserve its earlier; if it has a power of assimilation and revival, and a vigorous action from first to last. 

 JH Newman, Development of Doctrine, Chapter 5.  

He will go into considerably more detail, and give historical examples, in the rest of the book.   

Can his notes be used to discern between false and true positions in ongoing disputes on doctrine?   That's an ongoing question in itself, and you see a wide variety of answers.      Newman himself, it seems, was more concerned with developing a theory of how development HAD happened -- how what looks like a change, historically, can be an organic development.    

If development of doctrine is analogous to development of living things, then one would expect to see different historical circumstances for different types of doctrines.     We would see a process not entirely unlike how humans come to know -- usually in successions of approximations, with some false starts and dead ends, with more richness and nuance as time goes on. .... and sometimes, some forgetfulness of past understandings, so occasional need to circle back and revisit some things that have already been established.