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.
The human soul has sojourned in lower and higher forms, migrating from one to another according to the samskaras or impressions, but it is only in the highest form as a human being that it attains to freedom.
-Swami Vivekananda