Ask if this person is kind?

People with lofty ideals are good in nature, but they have to do bad things.

Seven or eight gentlemen left early, indicating that it is still too early to leave home and break the world alone. Seven or eight means fifteen.

Yang Wu is on the battlefield, which means that if this person wants to achieve something, he must go to the army.

The core meaning of the four sentences is: going out to be a soldier.