Rational optimism holds that the world will pull out of the current crisis because of the way that markets in goods, services and ideas allow human beings to exchange and specialise honestly for the betterment of all. So this is not a book of unthinking praise or condemnation of all markets, but it is an inquiry into how the market process of exchange and specialisation is older and fairer than many think and gives a vast reason for optimism about the future of the human race. Above all, it is a book about the benefits of change. I find that my disagreement is mostly with reactionaries of all political colours: blue ones who dislike cultural change, red ones who dislike economic change and green ones who dislike technological change.