The genome is a book that wrote itself, continually adding, deleting and amending over four billion years.

It is not a zero sum game. The simple idea of the gains from trade lies at the heart of the modern and the ancient economy, not the power of capital. There is nothing else to it.

Simple determinism, whether of the genetic or environmental kind, is a depressing prospect for those with a fondness for free will.

Trade is 10 times as old as farming.

This idea holds out hope that the human race will prosper mightily in the years ahead-because ideas are having sex with each other as never before.

Ecology, like genetics, is not about equilibrium states. It is about change, change and change. Nothing stays the same forever.

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.