Logical Fallacies

Class Activity                                     Logical Fallacy Ad                                        Ed Lessor

Preparation: I print out six definitions for specific logical fallacies from Stephen’s Logical Fallacy website. (I change these each term, but the latest version included: slippery slope, false dilemma, argument from ignorance, bandwagon, strawman, and ad hominem.) We have already discussed the concept of logical fallacies and why they are inappropriate for academic arguments that follow a code of “mature reasoning,” but we have not yet defined specific fallacies.  The class is divided into six groups. Each group is randomly assigned one of the logical fallacies.

Objective: The objective of the activity is to teach a handful of common logical fallacies to the students as they begin working with the construction of sound arguments. I want the class to be able to identify the fallacies by name, but more importantly, to be able to identify the type of flawed reasoning implied by each. The creative component of the activity leads to a very engaged understanding of how the fallacies function.

Activity: Each group is assigned the following goals: 1. Use the handout to learn the logical fallacy. 2. Be prepared to teach the fallacy to the class. 3. Use their own issues and topics for the unit to generate some examples of the fallacy. 4. Write an argument that uses the fallacy. (The argument that I assign to them is to write an advertisement for Sexy-Brite toothpaste.)

Each group reads their ad to the rest of the class without revealing the type of logical fallacy that they are working with. The class then discusses what seems to be flawed about the reasoning. The group then defines the fallacy and presents their examples to the class.

Unit Goals:
To identify logical fallacies and recognize their importance for both evaluating source arguments and drafting the convincing argument.

To develop a deeper understanding of the principles of soundness in the construction of mature arguments.

Course Goals
Extend knowledge of rhetorical concepts, demonstrated by a student’s ability to:

  • Compose effective arguments in different genres (such as academic and public media) and different modes (such as alphabetic, auditory, and visual modes, as well as multimodal texts that combine these strategies) designed to achieve multiple and specific purposes for multiple and specific audiences

Extend experience in composing processes, demonstrated by a student’s ability to:

  • Hone strategies for generating ideas, revising, editing, and proofreading mono- and multi-modal texts in disciplinary/professional/specialized discourse
  • Critique one’s own compositions and the compositions of others
  • Evaluate sources for accuracy, relevance, credibility, reliability, and bias

Extend mastery of argumentative conventions, demonstrated by a student’s ability to:

  • Select, evaluate, and integrate appropriate evidence for multiple genres, modes, and rhetorical situations