Mei Kuang Yu Xia (The Lower, the More Accurate the Comparison Is)
Someone once asked Zhuang Zi, "Where is the Dao you are always talking about?"
Zhuang Zi answered, "It is omnipresent."
The man persisted, "Please be more explicit."
"It is in the crickets and the ants."
"Why so low?"
"It is in the weeds and the grass."
"Why even lower?"
"It is in the tiles and the bricks."
"Why do you seek lower and lower comparisons?"
"It is in dung and urine."
The man lapsed into silence.
Zhuang Zi said, "Your question do not touch the essence of the Dao. When the market supervisor checks how fat a pig is by stepping on it, the lower part of the body he touches, the more accurate the check is."
What Zhuang Zi meant was that the more humble the investigated objects are, the more truth can be obtained.
Later, the phrase came to be used to describe situations or conditions which are steadily deteriorating.