以人为镜

Explanation: The success or failure of others as their own reference. 　　Usage: Partial official; as predicate; with compliment 　　Source: "Mozi non-offensive in the" gentlemen do not mirror mirror on the people in the water. Lens in water, to meet the volume; mirror to people, you know Kat and fierce. " 　　Examples: "Old Tang Wei Zheng Biography": "to the ancient as a mirror, one can know the rise and fall, ~, can see advantages and disadvantages." Thesaurus:  Human-Kam