It is the assumption of this book that there is a typical human nature. It is the aim of this book to seek it. Just like a surgeon, a psychiatrist can make all sorts of basic assumptions when a patient lies down upon the couch. He can assume that the patient knows what it means to love, to envy, to trust, to think, to speak, to fear, to smile, to bargain, to covet, to dream, to remember, to sing, to quarrel, to lie. The 'smile' of a baboon is a threat; the smile of a man is a sign of pleasure: it is human nature, the world over.

Prosperity has brought complications. Our lives are busier, faster, more stressful. They're nostalgic for a simpler, slower time.

The fuel on which science runs is ignorance. Science is like a hungry furnace that must be fed logs from the forests of ignorance that surround us. In the process, the clearing we call knowledge expands, but the more it expands, the longer its perimeter and the more ignorance comes into view.

The average Mexican lives longer now than the average Briton did in 1955. Infant mortality is lower today in Nepal than it was in Italy in 1951. The proportion of Vietnamese living on less than $2 a day has dropped from 90 per cent to 30 per cent in twenty years. The rich have got richer, but the poor have done even better.

The message from history is so blatantly obvious - that free trade causes mutual prosperity while protectionism causes poverty - that it seems incredible that anybody ever thinks otherwise. There is not a single example of a country opening its borders to trade and ending up poorer.

Our minds have been built by selfish genes, but they have been built to be social, trustworthy and cooperative.

Note even Jonathan Swift would dare to write a satire in which politicians argued that - in a world where species are vanishing and more than a billion people are barely able to afford to eat - it would somehow be good for the planet to clear rain-forests to grow palm oil, or give up food-crop land to grow biofuels, solely so that people could burn fuel derived from carbohydrate rather than hydrocarbons in their cars, thus driving up the price of food for the poor. Ludicrous is too weak a word for this heinous crime.