Not sarcastic. The Screwtape Letters is important literature because it was praised at publication, became lauded, and is an complete intellectual failure. The Screwtape Letters stands as a milestone of logrolling: the practice of approval due to who authored something rather than what the writing actually contains. The Screwtape Letters is a debate exposing one of the several weak intellectual foundations of Christian philosophy - but none of that critism was socially allowed for many decades. Such critism still causes many a panty to bunch. The Screwtape Letters is important because it is weak intellectualism, wrapped up in pretty good writing, but not good enough to disguise its intellectual bankruptcy, yet it still lauded.