[The Duke Ting asked whether there was a single sentence which could make a country prosperous. Confucius replied, "Such an effect cannot be expected from one sentence.] There is a saying, however, which people have -'To be a prince is difficult; to be a minister is not easy.' If a ruler knows this, - the difficulty of being a prince, - may there not be expected from this one sentence the prosperity of his country?"

Analects 13:15

When all those about you say, - "This is a man of talents and worth," you may not therefore believe it. When your great officers all say, - "This is a man of talents and virtue," neither may you for that believe it. When all the people say, - "This is a man of talents and virtue," then examine into the case, and when you find that the man is such, employ him. When all those about you say, - "This man won't do," don't listen to them. When all your great officers say, - "This man won't do," don't listen to them. When the people all say, - "This man won't do," then examine into the case, and when you find that the man won't do, send him away.

Mencius 1:2:7:4

Hence that which is antecedent to the material form exists, we say, as an ideal method, and that which is subsequent to the material form exists, we say, as a definite thing.

Yi king Appendix 3 1:12:78