溫故知新 [ㄨㄣ ㄍㄨˋ ㄓ ㄒㄧㄣ; wen1 gu4 zhi1 xin1]
  to review the old and know the new (idiom, from the Analects)
  to recall the past to understand the future
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  温故知新
  温古知新
  おんこちしん
  noun (common) (futsuumeishi)
  developing new ideas based on study of the past
  learning from the past
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