John Haigh takes the above quote as the epigraph for "Taking Chances", and makes his own significant contribution to scientific literacy. He concerns himself with "games of chance" in the broadest sense, from the National Lottery, quiz shows, casino games and card, dice and coin games, through game-theoretic "games" such as military conflicts, to all types of sports.
There are many sorts of games played in a "bunco booth", where a trickster or sleight-of-hand expert tries to relieve you of your money by getting you to place bets - on which cup the ball is under, for instance, or where the queen of spades is. Lots of these games can be analysed using probability theory, and it soon becomes obvious that the games are tipped heavily in favour of the trickster!
The idea is this. To start with, you will choose an envelope at random, say by tossing a coin, and look at its contents, which is a cheque for some number - say n. (By randomising like this, you can be sure I haven't subconsciously induced you to prefer one envelope or the other.) You want to make sure that the bigger the number is, the more likely you are to keep it, in other words, the less likely you are to swap.