鉴古推今
jiàn​gǔ​tuī​jīn

to learn from the past to understand the present

  1. 鉴 鑒 jiàn
    to examine
    to inspect, scrutinize, or appraise; to distinguish between things
  2. 古 gǔ adjective
    ancient
    ancient; old; from the distant past; referring to former times as opposed to the present
  3. 推 tuī nounverb
    to infer
    (bound form) to deduce, calculate, or investigate based on known facts
  4. 今 jīn
    modern
    modern; contemporary (as opposed to ancient 古 gǔ)