Fiction is usually thought of as prose, while poetry is given a separate classification. Essays are a form of prose usually differing from fiction in that the essay is considered a real document and not a tale. The distinction among these three forms is not always that clear, and often the genres are deliberately blurred. For that matter, critics often find elements of one type or writing echoed in another. A writer such as Thomas Wolfe, for instance, is often cited for the poetic nature of his prose. Steinbeck wrote what are called the intercalary chapters in The Grapes of Wrath in the form of essays on topics related to the larger fictional portion of the novel. Some poetry reads more like prose than what is thought of as poetry until the reader analyzes the interior tensions of the words selected and how they fit into the whole. In much modern fiction, the three elements may be used in various ways in the same work in order to achieve some purpose or to illustrate some concept more fully. How these three can be fit together can be seen with reference to the poetry of She Tries Her Tongue: Her Silence Softly Breaks by M. Nourbese Philip and the more prose work Written on the Body by Jeanette Winterson.
             The way the different genres are mixed depends on how they are mixed. Poetry and prose can be differentiated strictly in terms of the way language is used in each, but there are also distinctions to be made in terms of subject matter and the treatment of subject matter. When critics say prose is poetic, they often mean the choice and use of language, but they may also mean the way certain subjects are treated. Similarly, the essay form may be adapted to either poetry or prose when the writer adopts the sort of personal account style that infuses so many essays today, an approach that can make fiction seem more real and that can tie together a book of poems that otherwise might be treated only as individual works. These t...