Report, if you have a problem with this page“ It is the task of San shamans to activate their supernatural potency, to cause it to ‘boil’ up their spines until it explodes in their heads and takes them off to the spirit realms – that is, they enter a state of trance at the far end of the intensified trajectory. ”
James David Lewis-Williams
From : The Mind in the Cave: Consciousness and the Origins of Art