During the Warring States period, Mencius traveled to various states, advocating for benevolent governance. He typically only visited a state if invited by its feudal lord.

His student, Chen Dai, found this difficult to understand. Mencius then explained to him:

'Duke Jing of Qi once used banners to summon his gamekeepers during a hunt. Those individuals, embodying '不忘沟壑' (not forgetting the gullies, meaning being prepared to die for their principles), chose to sacrifice themselves rather than yield or come forward in a disrespectful manner. This demonstrated their strong character and integrity.

If I were to go without a proper invitation, what kind of decorum would that be?'