The term refers to the differentiation of the form and style of a literary work. It means that before putting words on paper, one needs to decide on the form and style appropriate to the thoughts and feelings to be expressed so as to produce a fine literary work with a high degree of harmony between form and content. In creating literary works, ancient scholars tended to decide on the style before writing. Literary critics in the Wei, Jin, and Southern and Northern dynasties discussed in detail the artistic features and rules of all literary styles and stressed that authors must choose an appropriate form or style to express their thoughts and sentiments and strictly follow the rules of the style, language form, and writing technique required by the chosen form or style. This, they believed, was the only way to create excellent literary works. Contrary to the term “style differentiation,” the term poti (破体) or “breaking-down styles” refers to the integration of different styles or forms of literary works by breaking down their boundaries. Style differentiation sometimes refers to differentiating the form or style of a literary work in order to attain a lofty character and realm of literature.