《新唐书·列传·卷一百》
古代皇帝身处危亡都想太平，太平时节却不一定想到危亡，所以不是所有君主都圣明。 
自古天子居危思安之心同，而居安虑危之心则异，故不得皆为圣明也。 
In ancient times, emperors who were in danger wanted peace, but in times of peace they did not necessarily think of danger, so not all monarchs were wise.