When someone asked Abraham Lincoln, after he was elected president, what he was going to do about his enemies, he replied, "I am going to destroy them. I am going to make them my friends."
Though fraud in all other actions be odious, yet in matters of war it is laudable and glorious, and he who overcomes his enemies by stratagem is as much to be praised as he who overcomes them by force.
Therefore, to estimate the enemy situation and to calculate distances and the degree of difficulty of the terrain so as to control victory are virtues of the superior general.