I divide the causes of human laughter into Joy, Fun, the Joke Proper,and Flippancy.... But flippancy is the best of all. In the first place,it is very economical. Only a clever human can make a real Joke aboutvirtue, or indeed about anything; any of them can be trained to talk _asif_ virtue were funny. Among flippant people the Joke is always assumedto have been made. No one actually makes it; but every serious subjectis discussed in a matter which implies that they have already found aridiculous side to it.
C. S. Lewis, _The Screwtape Letters_.
