History: Samurai Portrait

Bu consists of bun (文), literature or letters (and generally the arts of peace), stopping the spear. Bu prohibits violence and subdues weapons ... it puts the people at peace, and harmonizes the masses.
The radical shi (士) on the other hand seems to have originally meant a person who performs some function or who has the ability in some field. Early in Chinese history it came to define the upper class of society, and in the Book of Han this definition is given :
The shi, the farmer, the craftsman, and the tradesman are the four professions of the people. He who occupies his rank by means of learning is called a shi.
Wilson states that the shi, as the highest of the four classes, brandished the weapons as well as the books. bushi therefore translates as "a man who has the ability to keep the peace, either by literary or military means, but predominantly by the latter".