Wen-xin-diao-long is a book that talks about different types of writing and how they have changed over time. The author, Liu Xie, believed that writing should be useful and express emotions. However, he didn't focus on showing reality or reflecting society in his view of literature. This means that his ideas about literature can be seen not just in poems and stories, but also in everyday writing. Overall, Wen-xin-diao-long is a book that discusses the theory of writing styles.