"It's not like you just have any old hallucination, you'll have a visualisation of exactly what the ritual is set up to provide, so if you summon the Greek god Hermes you will see the Greek god Hermes. But I began to get different ideas about what these things really were and I was more interested in the effect rather than the explanation because I didn't believe in gods or devils or demons, but I knew that there was something - these were like mechanisms, these rituals that could trigger states of mind."