This book was recommended by a friend in Amsterdam, who meditates every day and is working on a Master's Degree in Religion. He is a very grounded person.
I believe that this book is a very important work in accurately describing psychoactive substances and how they relate to spirituality and personal growth.
It is interesting how people use LSD, peyote, mescaline, mushrooms, and even cannabis to expand or clarify their mind -- and commune with a higher power -- in many different settings.
The book also gives brief thoughts on why most organized religions dislike these methods -- arguments that may surprise you.
I recommend this book for the casual psychoactive drug user as to gain a better appreciation for what the their drug of choice can do -- other than a casual escape.
If I was to criticize this book, it would be in two ways. One -- why no conclusion chapter? ; and 2) The personal narratives are interesting, but tend to be numerous and wordy -- they could be edited more.