To see through someone's true intentions or thoughts as clearly as if looking into their internal organs (lungs and liver); to have one's motives completely transparent and obvious (often implying a negative or critical assessment of their true nature).
Era:
Ancient
Frequency:
Story:
During the Western Han Dynasty, Dai Sheng elaborated on the meaning of sincerity in 'The Book of Rites'. He asserted that a truly sincere individual must practice 'shen du' (慎独), meaning to be cautious and upright even when alone.
Those who fail to uphold 'shen du' engage in various misdeeds in private. When they encounter a gentleman of sincerity, they attempt to conceal their wrongdoings. However, they are unaware that the gentleman perceives them as clearly as if looking into their lungs and liver, rendering any attempt at concealment utterly futile.