(1) theory of "wonderful enlightenment"
The most important point of Yan Yu's poetic theory is "using Zen as a metaphor for poetry". He wrote in Cangzhou dialect? The comparison between Han Yu and Meng Haoran in Bian Shi shows that Han Yu's knowledge is higher than Meng Haoran's, but his poems are far inferior to Meng Haoran's, because Meng Haoran's poems are "only about wonderful enlightenment". He said: "Generally speaking, Zen is a wonderful realization, and poetry is also a wonderful realization." Wu Miao, who put forward the theory of "Miao Wu", is the core of Yan Yu's metaphor of poetry with Zen. "Wu Miao" was originally a Zen vocabulary of Buddhism, which refers to the subject's grasp of the "emptiness" of the world ontology. Nirvana's theory of namelessness says: "The metaphysical way lies in Wu Miao, and Wu Miao lies in truth." As far as poetry is concerned, "wonderful enlightenment is true" refers to the poet's true feelings and understanding of the beauty and reality of poetry. He said: "Only understanding is the right thing to do, but it must be true." Because "understanding is shallow and deep", each poet's understanding depth is different, which forms the difference of aesthetic value of various schools of poetry, that is, the difference of various systems.
(2) the theory of "different materials" and "different interests"
Song poetry lacks the rich and meaningful aesthetic taste of Tang poetry, and often takes words as poetry, arguments as poetry and talents as poetry. Yan Yu takes "wonderful understanding" and "interest" as the theoretical basis, and holds that: "Poetry is different from other materials and has nothing to do with books; Poetry has other interests and has nothing to do with reason. The ancients did not study and were not poor. The so-called people who don't care about the road and say nothing, go up. " Put forward the theory that "poetry has different materials and different interests" and criticize this tendency in Song poetry. The so-called "special material" means that the poet has a special talent embodied in "Wu Miao". He compared Han Yu with Meng Haoran and pointed out that Wu Miao's "special materials" were different from his academic ability. Han Yu's knowledge is higher than Meng Haoran's, but Yan Yu thinks his poems are far less than Meng's. This is the comment that "poetry has different materials and has nothing to do with books". The so-called "different interest" is about the aesthetic characteristics of poetry. The "interest" here is "interest", it is "interest" and it is a rational interest contained in the image.
(3) the theory of "knowledge first"
Yan Yu emphasized that learning poetry should be based on "knowledge". He wrote in Cangzhou dialect? "Poetry Discrimination" said: "People who study poetry focus on learning: they must be correct and determined to be high; Take the Han, Wei, Jin and Tang Dynasties as teachers, and don't be the following figures in Kaiyuan Tianbao. ..... So there is a saying: If you learn from it, you can only learn from it; Learn from it and you are next. " In other words, a poet should have a high degree of aesthetic knowledge, that is, aesthetic judgment. Only with "knowledge" can we distinguish and distinguish the differences of previous poems. So he added, "When writing poetry, we must distinguish between various systems, and then we should not be confused by the heresy." (Answer to the Book of Wu Jingxian's Uncle Lin 'an) Starting from a height, you can't be confused by the side door. He asked to be familiar with the ancient poems of the Han and Wei Dynasties, and then to consult famous Tang poets such as Li and Du. It can be said that "the unity of knowledge and practice" is precisely for the "wonderful understanding" of poetry.