Trade is 10 times as old as farming.

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.

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.

Considering the way evolution works, it should not be surprising if every man has got a Don Giovanni somewhere inside him.

The body is merely an evolutionary vehicle for the gene

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.

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.