being on the side of righteousness rather than the side of emotions
Definitions (粵典–words.hk)
語句
講道理,只要犯咗錯就算係親人朋友都無情講 referring to someone who is righteous and not tolerant of mistakes committed by other people(even his/ her friends or relatives)
認理不認人,幫理不幫親。
认理不认人,帮理不帮亲。
jing6 lei5 bat1 jing6 jan4, bong1 lei5 bat1 bong1 can1. To recognize and apply moral standards is better than to identify and help who makes mistakes.