The commonest metaphors would be questioned till some bitter truth had been forced from its hiding place.It's from Chapter 9 of Surprised by Joy. Lewis is talking of a tutor whom he described as "near to being a purely logical entity." He would never make small talk or use manners of speaking lightly and boldly questioned anything anyone said.
"These fiendish German atrocities--"
"But are not fiends a figment of the imagination?"
"Very well, then; these brutal atrocities--"
"But none of the brutes does anything of the kind!"
"Well, what am I to call them?"
"Is it not plain that we must call them simply Human?"
and on learning a foreign language:
We opened our books at Iliad, Book I. Without a word of introduction, Knock [Lewis's tutor] read aloud the first twenty lines or so.... He then translated, with a few, a very few explanations, about a hundred lines.... When he had finished he handed me over Crusius' Lexicon and, having told me to go through again as much as I could of what he had done, left the room. It seems an odd method of teaching, but it worked. At first I could travel only a very short way along the trail he had blazed, but every day I could travel further. Presently I could travel the whole way. Then I could go a line or two beyond his furthest North. Then it became a kind of game to see how far beyond. He appeared at this stage to value speed more than absolute accuracy. The great gain was that I very soon became able to understand a great deal without (even mentally) translating it; I was beginning to think in Greek. That is the great Rubicon to cross in learning any language. Those in whom the Green word lives only while they are hunting for it in the lexicon, and who then substitute the English word for it, are not reading the Greek at all; they are only solving a puzzle. The very formula, "Naus means a ship," is wrong. Naus and ship both mean a thing, they do not mean on another. Behind Naus, as behind navis or naca, we want to have a picture of a dark, spender mass with sail or oars, climbing the ridges, with no officious English word intruding.