Carlos Castaneda was an anthropologist. At the beginning of '60's , he met in New Mexico an old man, an indian who belonged to group of people that belived in an ancient religion. He became his apprentice and was tought their belives. He wrote his experiences in about 10 books. Very popular in late '60's and '70's. They belive that everything is energy. From a simple stone to human beings. Actually what they belive is not a religion the way we know! As they say it is a different way to see the world. They say, there are other realities ( besides ours ) but we are not able, not even to realise they exist! With certain training some can! They use lucid dreaming to manipulate their energy.! I hope I gave an idea about him! ( at least what I understood!) I belive it is worth reading his books! Also have a look at : www.cleargreen.com a site about his teachings Since there are many who wrote books about Castaneda trying to explain what he wants to say, I suggest anyone interesting,to read the books Castaneda wrote!