The Eighth Introduction to the Academy: The eighth "Nine Changes" discusses that generals commanding operations should deal with problems flexibly and flexibly according to various specific situations, and should not be mechanical and rigid and lead to failure, and puts forward requirements for generals. Sun Wu emphasized that when a general handles a problem, he must do the following: First, consider both the beneficial and harmful aspects of the problem. Think of the unfavorable factors in a favorable situation, and think of the favorable factors in an unfavorable situation. Secondly, different struggle methods must be adopted according to different struggle goals. Third, it must be based on full preparation and making the enemy invincible, and nothing can be left to chance. Fourth, we must overcome extreme temperament and consider issues comprehensively, carefully and calmly. Only by doing the above can we "get the benefit of the land" and gain the use of people. Sun Wu believed that a general must handle problems based on reality in order to defeat the enemy, so he did not need to execute the monarch's orders that violated the actual situation. Therefore, he Boldly put forward the military famous saying "the emperor's orders are not accepted".