Screwtape on Historicism

From C.S. Lewis' Screwtape Letters, letter 27:

The Historical Point of View, put briefly, means that when a learned man is presented with any statement in an ancient author, the one question he never asks is whether it is true. He asks who influenced the ancient writer, and how far the statement is consistent with what he said in other books, and what phase in the writer's development or in the general history of thought, it illustrates, and how it affected later writers, and how far it has been misunderstood (specially by the learned man's own colleagues) and what the general course of criticism on it has been for the last ten years, and what is the 'present state of the question'. To regard the ancient writer as a possible source of knowledge--to anticipate that what he said could possibly modify your thoughts or your behaviour--this would be rejected as unutterably simple-minded. And since we cannot deceive the whole human race all the time, it is most important thus to cut every generation off from all others; for where learning makes a free commerce between the ages there is always the danger that the characteristic errors of one may be corrected by the characteristic truths of another. But thanks be to Our Father and the Historical Point of View, great scholars are now as little nourished by the past as the most ignorant mechanic who holds that 'history is bunk'