This is the authoritative text book of Yoga, one of the six systems of Indian philosophy. Sanskrit Text and translation with commentary which provides a full picture of what Yoga is, what its aims are, how it can be practised, and what liberation of the soul means.
Take up one idea. Make that one idea your life -- think of it, dream of it, live on that idea. Let the brain, muscles, nerves, every part of your body, be full of that idea, and just leave every other idea alone. This is the way to success, and this is the way great spiritual giants are produced. Others are mere talking machines.
-Swami Vivekananda