Lewis wondered how an ancient religion could have anything to do with now. Wasn't Christianity old-fashioned, outmoded and a relic of the past? Hadn't it outlived its usefulness? From Owen Berfield, Lewis learned that for any supposedly outmoded idea, inquiry must be made as to why the idea went out of date, whether the idea was ever refuted, and if so, by whom, and how conclusively?
We must not assume that because an idea is old it is therefore false. Lewis later labelled this attitude "chronological snobbery." He defined this as "the uncritical acceptance of the intellectual climate of our own age and the assumption that whatever has gone out of date is on that count discredited." In other words, we take for granted that the prevailing ideas of our time and culture are unquestionably true.
The truth is that we need the help of the past to more accurately understand our own times. Lewis urges us to deliberately read old books in order to let the "clean breeze of the centuries" blow through our minds. He made it a general rule that one should read as many old books as new ones. Sometimes we need to go back in order to go forward. Jesus said that "every teacher of the law who has been instructed about the kingdom of heaven is like the owner of a house who brings out of his storeroom new treasures as well as old (Matt.13:52)."
No matter what period of history we live in, those things that are most relevant will always be the things that are unchanging and eternal. Lewis called them "first things." We must not buy into the lie that the newest is the best or be misled by the temptation to give in to a constant drive for novelty. After all, all that is not eternal is eternally out of date.
If the clock is telling the wrong time, then maybe it is time to turn it back. Listen to the wisdom of the past. Learn from history. That which is true is not always new and that which is new is not necessarily true. Think about it ...
[Summarised from chapter 3 of Art Lindsley's book C.S. Lewis' Case for Christ]
Click here for Objection #2 - The Problem of Evil.