About eighty years ago, Mr. Yen Fu (1853-1921) put forward three words for the principle of translation: “, expressiveness and elegance”. But Lu Xun (1881-1936) showed disapproval of Yen, and in his opinion “faithfulness” is above all the three in importance. He later put forward two words “faithfulness” and “smoothness”. He held his : “Rather to be faithful than smooth”; “Be faithful in thought and smooth in language.” In his both faithfulness and smoothness are important, but faithfulness first, smoothness second. Today we’d better take his two words as our principle of translation.
具体出处未知，不过可以知道是鲁迅说的