The author had quoted from this Upanishad and explained its ideas in several of his lectures, class-talks, and conversations. All this material, spread throughout the nine volumes of his Complete Works, has been brought together in this book for the first time. What makes this compilation a treasure trove of original ideas and masterly insights is that the author goes straight to the heart of the subject to focus on the essentials, and to evolve practical methods from abstract principles.
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