An excerpt from C.S. Lewis’s preface to Athanasius: On the Incarnation.
Naturally, since I myself am a writer, I do not wish the ordinary reader to read no modern books. But if he must read only the new or only the old, I would advise him to read the old. And I would give him this advice precisely because he is an amateur and therefore much less protected than the expert against the dangers of an exclusive contemporary diet. A new book is still on its trial and the amateur is not in a position to judge it. It has to be tested against the great body of Christian thought down the ages, and all its hidden implications (often unsuspected by the author himself) have to be brought to light. Often it cannot be fully understood without the knowledge of a good many other modern books.