David Lewis-Williams said that Cro-Magnon shamans would go into a trace state and then paint on the cave wall?

Some claim to dance into a trance like or convulsive state. Some Indians use mushrooms or peyote. There are many plants that can give an altered state of consciousness.Whatever theories exist about Shamans or Medicine men,they had an agenda,power over the people. They were the precursor of our religions. Any thing about a Shaman is suspect. I would rather believe they pretended trance to mystify the people and retain their power in collusion with the other Rulers. Perhaps Mr.Lewis-Williams is serving his own ends with what I opine as Ridiculous.

Probably because a lot of animist cultures today do trance state rituals and since most of the Cro-Magnon paintings are of animals, people in animal costumes, hunts, etc. it's a pretty solid theory that there was some animal-based religion going on. But, keep in mind that it's completely speculatory. None of the people back then had writing systems so nothing was recorded. The theory that they were in trance while painting is one of a great number of theories about the cave paintings. The way they would possibly achieve a trance state is also something that could never be conclusively known. Among modern cultures, sometimes a psychotropic substance is ingested, sometimes trance is achieved through rhythmic drumming, ritual dance, meditation--any number of different methods and combinations thereof.