A picture is worth a thousand words, or so they say. Yet our world, our civilisation has grown up on a foundation of words - laws, constitutions, treaties, charters, creeds - words that have tamed and liberated in equal measure. Our education, from earliest childhood, emphasises the importance of words. We take the world before our eyes and define it in a verbal language, and in so doing we capture it, understand it, celebrate it. But there are...