People who pass from stage two hallucination to stage three often experience a sensation of a vortex or rotating tunnel around them, and soon have ha… - Richard Leakey

Prehistoric images speak to us more evocatively than any other element of the archeological record: colorful, vibrant paintings of horses, of bison, of a panoply of animals and humans that often seem alive and in motion. And yet there is a dimension of unreality about them... The images seem plucked from life... often arranged chaotically to our eye, frequently superimposed... sometimes apparently incomplete. ...There is an enigma in these images, a profound challenge to our understanding of the past.

It appears that the evolutionary process promotes its own progress: learning about the environment (which demands a certain intelligence) means living in a stable social mileau (which demands at least an equal and possibly a greater intelligence); as social intelligence increases, so too will the ability to learn; this in turn encourages an even longer social apprenticeship; and longer group living leads to more social intelligence.

The painted, engraved, and carved images of prehistory are threads from past cultures, and we are foreigners trying to interpret their meaning. Perhaps more than anything else, art can be fully understood only in the context of the culture that produced it.