The poetics ideas about praise and satire,after a longterm development from the Two Han Dynasties to the Tang Dynasty,looked realistically progressive.Until the Song Dynasty,however,they appeared backward which advocated praise and excluded satire.Actually,the ideas of the Song were closely related to political influence of the time.Many law cases of poetry,which first appeared and also thrived in the Song,gave rise to the poetics ideas with only praise but not satire.