《文心雕龙·时序》
这些歌谣写作的道理，是和时代一起演变的；时代像风一样在上边刮着，文学就像波浪一样在下边跟着震动。
故知歌谣文理，与世推移，风动于上，而波震于下者也。
The principles of writing these songs changed with the times. The times thundered overhead like the wind, and literature trembled below like waves stirred by the wind.