What changes should Ye Xie point out in the form and content of poetry?

Ye Xie believes that the history of poetry is an alternating process of prosperity and decline, and in this historical process, poetry will constantly evolve to a better and richer state. Ye Xie pointed out that if poetry sticks to an orthodox system in form and content, it will inevitably become obsolete due to rigidity. On the contrary, the changing era is the real creative period, which will eventually bring new prosperity to poetry. He believes that the "elegant style" of blessing has positive changes, and its positive changes depend on time, which means that the political style is lost because of gains and polluted because of prosperity. This is a poem with time; Time has changed, and poetry is therefore. Time changes and loses its correctness, and poetry changes and still loses its correctness, so there are ups and downs and the source of poetry. I said that there were positive changes in poetry in later generations, and positive changes were related to poetry, referring to the differences in form, tone, meaning, words and the rise and fall of new things. When the poem said this, the poem gradually changed, and then changed. Therefore, in the Han, Wei, Six Dynasties, Tang, Song, Yuan and Ming dynasties, it rose and fell, but it changed in order to save the decline of the Emperor, so it declined and was handed down from generation to generation, and poetry also flowed.