The Art of War by active 6th century B.C. Sunzi

14. (2) By attempting to govern an army in the same way as he

administers a kingdom, being ignorant of the conditions which obtain in an army. This causes restlessness in the soldier’s minds. [Ts’ao Kung’s note is, freely translated: "The military sphere and the civil sphere are wholly distinct; you can’t handle an army in kid gloves." And Chang Yu says: "Humanity and justice are the principles on which to govern a state, but not an army; opportunism and flexibility, on the other hand, are military rather than civil virtues to assimilate the governing of an army"—to that of a State, understood.]