ㄐㄧㄢˋㄨㄤˇㄌㄞˊjiànwǎng‑zhīlái

鉴往知来
  1. 借鑒過去經驗教訓未來發展變化鑑往知來 不用)​。 研究歷史為了鑒往知來總結經驗吸取教訓」。

to observe the past to foresee the future (idiom, taken loosely from Book of Songs)​; studying ancient wisdom gives insight into what is to come
(expr. idiom.)​ observer le passé pour prévoir le futur, l'étude de la sagesse ancienne rend clairvoyant sur le futur