psychedelics are part of the diet with dennis mckenna

http://www.danielvitalis.com/rewild-yourself-podcast/dennis-mckenna-on-hunting-magic-mushrooms-and-dmt-in-south-america

Dennis McKenna points out that our natural diet is psychoactive.  We bred the alkaloids out of plant foods because they taste bitter.
All true psychedelics are serotonin 2A agonists.  They act like the native neurotransmitters but have  a different effect.   They change our relationship to nature.  The idea of separation from nature and the devaluation of nature is really the legacy of 2000 years of Judeo-Christian influence on our culture where the message is 'don't value existence in this world your reward is in the next world.'