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 disciple must have great power of endurance. Life seems comfortable; and you find the mind behaves well when everything is going well with you. But if something goes wrong, your mind loses its balance. That is not good. Bear all evil and misery without one murmur of hurt, without one thought of unhappiness, resistance, remedy, or retaliation. That is true endurance; and that you must acquire.
-Swami Vivekananda