To the guy (or lady) who said about the "summoning failure".
You obviously missed the point of the book. Although the first half is about how to change your life or to be a better person, the second half (Rituals) is obviously one of two things:
a) An activity to undertake for fun
b) A parody.
There are no such thing as demons. You obviously didn't read the book properly.
This book stays with me wherever I go, mainly just so I can pull it out and scare prudish people. It didn't change my life massively as I have been living it, even before I heard of it. However, for someone who is looking for the path to self-happiness, buy this. It's less than 4 quid, you cheapskate! ;)