鑒往知來 [ㄐㄧㄢˋ ㄨㄤˇ ㄓ ㄌㄞˊ; jian4 wang3 zhi1 lai2] 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 ◄ ►