Argumentation and Persuasion

By Dr Art Lynch

Persuasion and Understanding Argumentation

Understanding Argument

The well-constructed argument forms the foundation of persuasive speaking. An argument consists of three elements: claims, evidence, and reasoning. Claims lay the groundwork for the thesis of your speech, answering the question "What am I asserting?" Every claim includes at least one premise and a conclusion. When speakers use an enthymeme, they omit part of the claim, leaving the audience to complete the claim. Qualifiers moderate a claim, indicating where there might be exceptions to the speaker's position.

Evidence refers to the supporting materials presented to back up the claim, answering the question "What is the support for my assertion?" Speakers may use logical appeals (logos), appeals to the speaker's credibility (ethos), emotional appeals (pathos), or appeals to cultural beliefs and values (mythos). Generally the strongest arguments are those that effectively integrate all four types of appeals. In addition, evidence should be relevant to the topic, come from highly credible sources, and represent a diversity of sources.

Reasoning is how speakers connect their evidence and claims. Reasoning answers the question "How are my supporting materials and assertions linked together?" and shows the audience how the evidence you've chosen provides justification for your position on the topic. Persuasive speakers rely on four types of reasoning: deductive, inductive, causal, and analogical. Deductive reasoning refers to arguing from a general principle to a specific case. Inductive reasoning involves giving examples in support of a claim. In causal reasoning, the speaker argues that something caused something else. Speakers using analogical reasoning compare two things that share similarities.

A fallacy occurs when an error is made in constructing an argument. Although fallacies may be persuasive, they are nonetheless a deceptive and unethical approach to convincing an audience. Fallacies may stem from errors in claims, evidence, reasoning, or responding. Common fallacies in claims are false dilemma, begging the question, slippery slope, and ad ignorantiam. Fallacies in evidence include red herring, ad populum, appeal to tradition, and comparative evidence. Division, hasty generalization, post hoc, and weak analogy are fallacies in reasoning. Audience members responding to persuasive arguments may also use fallacies, including ad hominem, guilt by association, caricature, and loaded words.

Why seek out opposing views?

Trust and Risk-taking.

Critical Thinking

Why learn to speak in public?

Critical Thinking Community Information and resources about critical thinking.

Logical Fallacies: The Fallacy Files Developed

by Dr. Gary N. Curtis, the site includes definitions, examples, quotes, and resources related to fallacies.

The Reasoning Page Developed

by Professor Bruce B. Janz
at the University of Central Florida,
this page includes links to online resources
in argumentation, critical thinking,
formal reasoning, the history of logic,
and reasoning in context.