First, writing and speaking are processes. A process is everything a writer or speaker does to prepare a discourse. The more complete the process, the more successful the writer or speaker will be. A successful writer or speaker considers his/her purpose, identifies his/her audience, selects a topic, generates information, organizes the information, creates a working thesis, writes a first draft, revises the discourse, edits the discourse, and titles the discourse.
Second, writing and speaking are rhetorical processes. Rhetoric is the use of signs, symbols, images, language--either written or spoken--for the purpose of informing, persuading or moving an audience. Rhetoric is a practical art, an art of doing, as distinguished from a productive art, an art of making, and from a speculative art, an art of inquiring. Rhetoric is an end-means art. In other words, given an end--the persuasion of a particular audience, for example--and a specific issue--for example, whether or not to eat broccoli--the writer or speaker must decide the means to affect his/her end. The means will vary because every discourse grows out of a particular context, a certain situation. The audience determines the type of discourse--whether it focuses on past, present or future events--and the audience judges the discourse on the basis of its rhetorical appeals.
When communicating with an audience, the writer or speaker must resort to three kinds of rhetorical appeals. Logos (Greek for "word") refers primarily to the internal consistency and clarity of the discourse and to the logic of its reasons and support. With the logical appeal, the writer or speaker seeks to manage the truth and validity of his/her argument through inductive and/or deductive reasoning. An argument is a group of statements, one or more of which (the premises) provide support for one of the others (the conclusion). A statement is a sentence that is either true or false, such as the following declarative sentence. Broccoli is an ample source of vitamin A. Questions, proposals, suggestions, commands and exclamations are not statements. Arguments are not facts (immediately verifiable information), and they are not opinions (individual, subjective experiences of personal taste).
An inductive argument is one in which the premises support the conclusion in such a way that if the writer or speaker assumes they are true, then it is only probable the conclusion is true. Some key words in inductive arguments are probable, improbable, plausible, implausible, likely, unlikely and reasonable to conclude. A strong inductive argument is one that if the premises are assumed to be true, then it is only probable (more than 50%) the conclusion is true. An example of a strong inductive argument follows. A barrel contains 100 apples. I selected 80 apples, and all of them were ripe. Therefore, probably all 100 apples are ripe. A weak inductive argument is one that if the premises are assumed to be true, then it is not probable the conclusion is true. An example of a weak inductive argument follows. A barrel contains 100 apples. I selected three apples, and all of them were ripe. Therefore, probably all 100 apples are ripe.
A deductive argument is one in which the premises support the conclusion in such a way that if the writer or speaker assumes they are true, then it is impossible for the conclusion to be false. Some key words in deductive arguments are necessarily, certainly, absolutely and definitely. A sound deductive argument is a valid argument with true premises. In other words, if the writer or speaker assumes the premises are true, it is impossible for the conclusion to be false. An example of a sound deductive argument follows. Broccoli is an ample source of vitamin A. You are deficient in vitamin A. Therefore, you definitely need to include broccoli in your diet. An unsound deductive argument is one in which a false premise or several false premises support the conclusion. An example of an unsound deductive argument follows. Broccoli is not an ample source of vitamin A. You are deficient in vitamin A. Therefore, you definitely need to include broccoli in your diet.
Pathos (Greek for "suffering" or "experience") refers to the pathetic (emotional) appeals to an audience's imaginative sympathies, to their capacity to experience what the writer or speaker has experienced. Concrete language (specific details) heightens a writer's or a speaker's emotional appeal. Specific examples and illustrations give a sense of presence and emotional resonance to a discourse. Brief narratives--real or hypothetical--that either lead into a claim or embody one implicitly will appeal to an audience's imaginative sympathies. Another way to incorporate pathos is to select words, metaphors or analogies with connotations that match the purpose of the discourse. One of the most powerful ways to engage an audience emotionally is to incorporate visual images into the discourse. However, the writer or speaker must reserve his/her emotional appeals for their proper context.
Ethos (Greek for "character") refers to the credibility of a writer or speaker. A writer or speaker conveys ethos through his/her investment in his/her thesis (claim), through his/her consideration of alternative viewpoints (rebuttals), through the tone and style of his/her discourse, through his/her reputation for honesty and expertise independent of the discourse, and through his/her projection of an image of good moral character, good will, and good sense.
An audience is the primary determinant of the means that a writer or speaker chooses to affect his/her purpose. The writer or speaker must be conscious of his/her audience, and he/she must have knowledge of that audience. Thus, the writer or speaker must ask questions about his/her audience before he/she prepares a discourse. Who is my audience? How much does my audience know or care about my issue? What is my audience's current attitude toward my issue? What will be my audience's likely objections to my argument? What values, beliefs or assumptions about the world do my audience and I share?
The third approach to academic discourse is that students are a part of an academic community when they write and speak, so their arguments must be logical. Because formal logic (logos) is too rigid for everyday arguments, which are often unstable and contingent, Stephen Toulmin developed a scheme for argumentation for everyday use. Arguments operate at the level of individual sentences. To ensure his/her audience understands the interconnectedness of his/her sentences, the writer or speaker must establish a logical form of argumentation. The form of an argument may show the sources of its validity and determine whether the audience accepts or rejects it. A valid argument must make a claim--an assertion of truth open to question. A valid argument must have grounds--reasons for and evidences of the claim. A valid argument must have warrants--general, hypothetical statements that link the claim with the grounds. A statement may serve as a claim, a warrant, or both. A valid argument must have backing--justifications (moral principles, testimony of experts, references to texts, or empirical justifications) for the claim. A writer or speaker must consider rebuttals--opposing evidence or arguments against the claim--and qualify (modify, limit or restrict) his/her claim.
To generate a complex thesis for an extended argument, a writer or speaker first asks himself/herself if there is something (an act) for consideration (a question of fact). Second, the writer or speaker asks what the nature of the act is (a question of definition). Third, the writer or speaker asks what the quality of the act is--that is, if it is right or wrong, good or bad (a question of evaluation). Fourth, the writer or speaker asks if there is a reason that justifies the act (a question of cause and effect). Finally, the writer or speaker asks what he/she can do (a question of policy). His/her answer to each question, in an academic essay or speech, will function as a claim, and each claim will function as a topical sentence. The complex thesis will be an amalgamation of all the topical sentences (claims). Certainly each of the aforementioned questions may function as the basis for an independent argument, and in such cases each answer (claim) will function as a thesis.
Please refer to "A Brief History of Rhetoric" for more information on the rhetorical appeals, and for more information on argumentation, please refer to the post, "The Components of an Academic Argument."