《论衡·卷十一·答佞篇》
所以君主能疏远谗人而亲近仁人，不能识别贤人与佞人。
故人君皆能远谗亲仁，莫能知贤别佞。
Therefore, a ruler is able to distance himself from slanderers and draw close to gentlemen, but he is not able to distinguish between worthy and flattering men. 