After a discussion with his grandfather about the words their native Lakota Sioux tribe use to discuss war and their warriors, story teller Joseph Marshall III writes:
"One day, still somewhat confused by the seemingly convoluted labels, I asked my grandfather for some kind of clarification. Consequently, he brought up an entirely different phrase and its concept: nagi wica, or "shadow man." He expounded at some length on the issues of war and warriors. His explanation was a foundation for insights I am still developing over this most chaotic of human institutions, and of understanding those who are thrust into war or go by choice.
In my grandfather's opinion, war is really a fight between the good and the bad sides of humans, and both emerge during the hostilities. It is within each of us to bring out the best or the worst part of ourselves. In all endeavors, he said, we must strive for balance, even within the context of war." -- Joseph M. Marshall III, "Walking with Grandfather: The Wisdom of the Lakota Elders."
In saying this, Marshall's grandfather, and Marshall himself, are espousing some of the central concepts of the Warrior in the Tao, that of integrating the yin and the yang, the darkness and the light, within the same being, and that in that route lies greater emotional and spiritual health.