What does it mean to be human and what kind of people were our ancestors? The fabulous and mysterious cave paintings in France have long been thought to provide a window into the past - if only we could understand them.Now remarkable evidence from the trance-dances of Namibian bushmen and research on hallucinations by psychologists in Britain and the USA has been compared with the images in the caves themselves. The result is an astonishing new interpretation of the images. We can now see into the minds of our stone age ancestors and reconstruct the world of the cave-painters.