Your man has been accustomed, ever since he was a boy, to have a dozen incompatible philosophies dancing about together inside his head. He doesn’t think of doctrines as primarily ‘true’ or ‘false’, but as ‘academic’ or ‘practical’, ‘outworn’ or ‘contemporary’, ‘conventional’ or ‘ruthless’. Jargon, not argument, is your best ally in keeping him from the Church. Don’t waste time trying to make him think that materialism is true! Make him think it is strong, or stark, or courageous— that it is the philosophy of the future. That’s the sort of thing he cares about.

-- C.S. Lewis, The Screwtape Letters