From caffeine and alcohol, to cannabis, ketamine and ecstasy, psychoactive intoxicants are widely found in western culture.  Although in some cases illegal, and potentially addictive, they are in large part seen as relatively unimportant additions to our lives.  But the use of intoxicants is found across the globe and it seems cultures have always used them.  Yet their real function and purpose is unknown.  From the peyote of the Maya and Aztecs, to the amanita mushrooms of Russian shamans, across the world psychoactives are found in religious and spiritual ceremonies stretching back thousands of years.  Moreover historians argue the dominant drug in a culture can have profound consequences.  Some claim the arrival of caffeine replaced the haziness of alcohol with the clarity of coffee initiating the Enlightment through the coffee house debating culture and the formation of intellectual elites.   

Should we see psychoactive intoxicants as central to culture and thought, and are some preferable to others?  Are they vehicles of pleasure and hedonism, or do they provide deeper psychological and spiritual functions?  Or are all intoxicants damaging to culture and potentially to our personal lives?