Purpose (Rhetoric)

Purpose refers to the writer’s reason for writing.

Purpose is also known as Aim, or Goal.


Like an onion that is peeled, revealing multiple layers, a text may have multiple purposes. A persuasive essay, for example, may have paragraphs that inform, paragraphs that persuade, paragraphs that threaten, and paragraphs that request information.

The purpose refers to the main idea of the text. Once you’ve determined your main idea, it is lot easier to stay on topic. In other words, to keep your focus you must have a main idea and supporting points. As you revise or compose, ask yourself: “How does this paragraph—and all the sentences it contains—support my main idea?” If it does not, or if it’s not clear, then you’ve probably lost your focus because you’ve included unnecessary information. A clearly focused essay will usually assert one idea—in the form of a thesis statement—and will then present a logical progression of related points that help prove the main idea.  A focused essay leaves the reader with a feeling of understanding, rather than confusion. It’s what people refer to as the “flow” of the essay.

Writers, teachers, and critics often talk about purpose in two distinct ways:

  1. The Global Perspective (aka Macro Level) concerns the writer’s overarching goals.
    • For instance, the primary purpose of the U.S. Constitution is to outline the basic rights of its citizens.
  2. The Local Perspective (aka Micro Level) refers to the writer’s purpose at the section, paragraph and sentence level.
    • For instance, the Preamble of the U.S. Constitution outlines the reasons the constitution was written and outlines the goals of the text. Next, Article 1 outlines the roles and powers of the three branches of government.

Knowing your purpose is a bit like knowing your destination and plugging it into a GPS system. For rhetors, after considerations of audience, little is more important than purpose:

  1. Purpose informs writing processes:
    Once you know your purpose, you can identify how you need to research, organize, revise, and edit information.
  2. Purpose is an heuristic, a method of invention:
    Contemplating your purpose in relation to your audience inspires rhetors:
    • Once you know your purpose, you can articulate your thesis, research question, and organizational strategy
    • purpose stimulates critical thinking because it brings into focus what to say and what not to say.
  3. Purpose determines genre:
    Genres reflect shared textual expectations between readers and writers. Genre reflects the histories, activities, and values of communities of practitioners. And the actions of these practitioners are determined by shared purposes.

Because life is complicated, so are purposes. People write documents for countless reasons, including

  1. Record: Keep a record of events or information.
  2. Reflect/Explore: Write in a journal, attempt to make sense of something or to shape a new idea.
  3. Inform: Objectively report an event.
  4. Demonstrate Knowledge: Prove, in school, that you’ve learned course content.
  5. Summarize: Report someone else’s words, theories, and research in your own words.
  6. Explain: Help readers understand a difficult concept, theory, or event.
  7. Analyze: Break down a problem into parts.
  8. Persuade: Change minds, invoke action.
  9. Theorize: Speculate on possible causes and effects.
  10. Entertain: Bring joy, amazement, and thrills.

Purpose has been a subject of significant academic study. Since antiquity, theorists have have speculated about ways purpose shapes content.

In the 1970s through the 1990s, this effort to analyze the effects of purpose on the shape of content endured. Building on the shoulders of Samuel Newman’s work, James L. Kinneavy (1971) postulated there are four primary aims, or purposes, for communication:

Expressive Discoursee.g, personal journals
Referential Discoursee.g., scientific, informative, and exploratory discourse
Literary Discoursee.g., novels, poems, short stories
Persuasive Discoursee.g., proposals, advertisements, recommendation reports

In 1975 James Moffett categorized the texts of eleven and eighteen old students in Great Britain. Judith Langer and Arthur Applebee followed up that study with How Writing Shapes Thinking in 1987, replicating the methods of Moffett’s study yet focusing on the writing of U.S. students. Langer and Applebee also extended this analysis by theorizing the effects of different discourse purposes on cognition.

[ See Thesis, Research Question, Title, Purpose (Information Literacy > CRAAP Test) for a discussion of the role Purpose in interpretation. ]

Works Cited

Britton, James, Tony Burgess, Nancy Martin, Alex McLeod, and Harold Rosen. The Development of Writing Abilities (11-19). London: Scho0ls Council Publications, 1975.

Connors, Robert J. The Rise and Fall of the Modes of Discourse, College Composition and Communication, Vol. 32, No. 4 (Dec., 1981), pp. 444-455.

Kinneavy, James L. A Theory of Discourse. Englewood Cliffs , TV. J.: Prentice-Hall, 1971.

Langer, Judith A., & Applebee, Arthur N. (2007). How Writing Shapes Thinking: A Study of Teaching and Learning. WAC Clearinghouse Landmark Publications in Writing Studies. The WAC Clearinghouse. https://wac.colostate.edu/books/landmarks/langer_applebee/ (Originally published in 1987 by National Council of Teachers of English)