大公无私

Origin and story

Guanzi (管子), Xing Shi Jie (形勢解), presents wind and rain as an image of impartial action. Wind does not choose between high and low status or attractive and unattractive things; rain does not favor the strong over the weak. The passage calls them supremely public-minded and free from private preference, using the related wording 至公而无私.

The later idiom applies that ideal to human decisions. Its concern is that public duties or shared interests should not be distorted by personal likes, family ties, or gain. There is no single courtroom drama in the source: nature provides the comparison for evenhanded conduct.