I've heard different opinions about the authors that's why I wanted to check the book by myself. And I must say that I agree with those who say that Gannon and Life are radicals in the yoga world. I didn't enjoyed it, I like spiritual development but this is too much for me. The book is not really reader-friendly. on one hand, most of the time authors are stuck on their own principles , but on the other hand sometimes off base and preachy. i didn't like it so much.