The main object of this book is to discuss the science of Yoga in as simple and rational a manner as possible, and also to debunk some of the nonsense that continues to be said and believed on the subject. A must for all those are eager to clarify their conception about Yoga.
The important thing is how much less you think of the body, of yourself as matter -- as dead, dull, insentient matter; how much more you think of yourself as shining immortal being. The more you think of yourself as spirit, the more eager you will be to be absolutely free from matter, body and senses. This is the intense desire to be free.
-Swami Vivekananda