人非生而知之者，孰能無惑 [－－－－－－－－－－无－]

Jyutping
Pinyin rén fēi shēng ér zhī zhī zhě , shú néng wú huò

Definitions (CC-CEDICT)
  1. Knowledge is not innate to man, how can we overcome doubt?
  2. We are not born with knowledge, how does one achieve maturity? (i.e. without guidance from a teacher - Tang dynasty essayist Han Yu 韓愈|韩愈[Han2 Yu4])