A special feature of the book is that the learned Swamiji quotes copiously from various Srutis, Smritis and Puranas as also from different orthodox commentators to explore the real meaning of the Mantras of the Ishopanishad.
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