A word about the physical effects of pot: In India in the 1800's the English wanted to tax pot but it was suggested that if it were bad for you, taxing it would be immoral. So they did a major study on a population in which it had been a part of the culture for centuries. The medical commision was unable to find anything wrong with pot (it was the 1880's, I think. Not modern but the science was good enough for what they were doing.). They ended up taxing salt anyway.