Lu Xun highly recommended Liu Shipei's Literary History of the Middle Age, especially his analysis of the innovation of the literature of the Jian'an period. The History represents Liu's academic thoughts during the last few years of his life. However, one should be careful not to appraise Liu's arguments solely on the basis of Lu Xun's presentation, as their concepts of literary history differed in a significant way. Another notable difference occurred between the thoughts of the early and later stages of Liu's life. In the early stage, Liu was heavily influenced by Darwinism. He proposed a linear progression of literary history. In the History, Liu abolished the model and showed remarkable insights in describing the changes of various genres with great details.