《贞观政要·卷二·论任贤》
如果您只做一个守住领地的藩王，那么用不着他，可是如果您要统领四海，那么非此人不可。 
若大王守藩端拱，无所用之；必欲经营四方，非此人莫可。 
If your only wish is to be the feudal lord of your territory, then you do not need him. However, if you wish to lead the people of the world, you need him more than anyone else.