When a just war of defense turns into a war of revenge, it ceases to be a just war and becomes an unjust war of aggression. That explains why Robert E. Lee—who followed the conventions of civilized warfare agreed upon in the eighteenth and nineteenth centuries—saw his role as defense of the South, and not as aggression against the North. In 1863, he said:

“In order to succeed in business a man does not need a degree from a school of business administration. These schools train the subalterns for routine jobs. They certainly do not train entrepreneurs. An entrepreneur cannot be trained. A man becomes an entrepreneur by seizing an opportunity and filling the gap. No special education is required for such a display of keen judgment, foresight, and energy.”—Ludwig von Mises, Human Action