Brhadaranyaka Upanishad - This book presents a lucid exposition of select portions of this Upanishad in the light of modern thought and modern needs. The Revered Swami has done this by freely drawing from contemporary scientific thought, biology, and physics, and by laying stress on the relevance of Vedantic ideas to these areas of modern thought.
There is only one sin. That is weakness.... The only saint is that soul that never weakens, faces everything, and determines to die game.
-Swami Vivekananda