Unit 6: Detecting Fallacies
NOTE: This guide supercedes the one in the book. The version in the textbook (written in December 1999) is inaccurate in at least two respects: the kinds of questions asked in the test, and the coverage of some of the fallacies. The tests for Unit 6 will consist of two kinds of questions, just as in unit 5:
These are multiple choice questions of the variety: "circle all that apply". Sometimes you might have to circle every answer following the question; sometimes you will circle none. The material for them is drawn entirely from the descriptions of the fallacies found in the Philosophy and Logic textbook. Pay particular attention to (a) the necessary and sufficient conditions for committing a particular kind of fallacy; and (b) the descriptions of the distinctions between different kinds of fallacies. Study those passages very carefully: all the answers are found in them!
Important Note:These multiple choice questions will include questions on the characterizations of the fallacies of clarity (first covered in unit 3), so review those too. This section will also include some questions about the "strawman" fallacy. The book (on p. 6-5) says that "strawman" will not be covered in the argumentative passages for which you must name the fallacy. While it is still true that you won’t have to identify any strawman fallacies (in part 2 of the test), there will be some multiple choice questions about them, so read the description carefully.
Again there aren’t any exact duplicates of the multiple choice questions from the test in the book, but the questions are drawn very closely from the descriptions of the fallacies in the textbook. As an example of (a) you might be asked what conditions are necessary or sufficient to show that an argument equivocates, why begging the question is a fallacy, or what one must do to commit a strawman. As examples of (b), you might be asked about the distinction between equivocation and slippery slope, about the difference between ad hominems and valid attacks on the testimony of a witness, or the distinction between fallacious appeals to authority and legitimate ones.
These will include:
I. Formal fallacies
II. Informal fallacies
A. Fallacies of clarity
B. Begging the Question
C. Fallacies of relevance
We have already done I and II.A, in units 1 and 3. These will be briefly reviewed, mostly to introduce the technical definition of a fallacy; and then we focus on II B and C. Statistical fallacies will not be included in this unit.
This section of the test consists entirely of 20 brief argumentative passages. Some of them are valid, and if so you are asked to name the standard argument form it employs (see § 6.1). The others commit some fallacy, and you are asked to name the fallacy the passage most clearly commits. Just as in unit 5, you must name a fallacy for which there is sufficient evidence to convict the author, not merely one whose absence is not precluded by the text. See the "important note about these problems" in §6.5. The specimens we examine do not need to prove their innocence; you must prove their guilt.
Study the descriptions of the various kinds of fallacies carefully. The summary decision tree in section 6.5 should be helpful. It includes all the names of fallacies you need to know for this section. (As explained above, "strawman" will not be found in part 2 of this test, though it will be mentioned in part 1.)
On fallacies of clarity you might want to review exercises 3.6, 3.7, and 3.8. The critical exercises for formal and informal fallacies are 6.1 and 6.5 through 6.9. The latter are all actually items from old tests or quizzes I wrote, so you can see what kind of question I ask. Other exercises give specific practice on some of the more difficult fallacies. For example, ad hominem (6.2), argumentum ad verecundiam (6.3), and circular reasoning (6.4). The answers to these should also be helpful in studying for part 1.
Identifying fallacies is much harder than it looks; you will need to practice as much as you can. You may use Latin names or not, as you wish. "Argumentum ad verecundiam" and "appeal to authority" are equally acceptable.
Recommended exercises from Patrick Hurley’s Concise Introduction to Logic:
This is the optional but recommended text for this course, and it has some useful exercises for this unit. The exercises include true/false questions that will help with part 1 of our tests, and lots of "name that fallacy" items like those in part 2.
On Fallacies of Relevance read section 3.2 and try exercise 3.2, p 133, parts I and II, which is also on the CD-Rom. Hurley does include some fallacies for which you will not be held responsible (Accident, Ignoratio Elenchi, Red Herring), and those you should just ignore. Don’t rely on his characterizations of the fallacies; they are in places imprecise, and mine are the ones that you will be examined on.
In section 3.3, fallacies of weak induction, Hurley places Appeal to Authority, Appeal to Ignorance, and Slippery Slope, along with three other fallacies that won’t be on our tests (Converse Accident, False Cause, and Weak Analogy). If you ignore the latter, exercise 3.3, p 148, parts I-III, is quite useful (and also on the LogicCoach CD).
Section 3.4 is least useful, because it has the highest proportion of fallacies that won’t be covered on our tests. Hurley puts Begging the Question, Equivocation, Composition, and Division in this section, along with 4 others that we don’t cover. Exercise 3.4 though includes sections (I-III) that include all the different fallacies from the entire chapter, and is worth trying.
Exercise 3.5 (part I, p 187-97) is also good practice for section 2 of our test. It has sixty items illustrating fallacies found in editorials and news magazines. It is also on the LogicCoach CD.