Week 10 (March 17 - 23): Fallacies of Unclarity
CONTENT: This week’s lectures will define fallacies as common but tempting mistakes in argument. Then we will explore two very common kinds of fallacies that depend on unclarity in language — specifically, slippery slope arguments that depend on vagueness and equivocations that exploit ambiguity. The lectures will close by distinguishing several kinds of definitions that can help to avoid or respond to fallacies of unclarity. READING: Understanding Arguments, Ninth Edition,Chapters 13 and 14
Week 11 (March 24 - 30): Fallacies of Relevance and of Vacuity
CONTENT: This week’s lectures will look at fallacies in which the premises are irrelevant to the conclusion, or in which the premises cannot be reasonably accepted before we have reasonably accepted the conclusion. The first group includes arguments ad hominem and fallacious appeals to authority, to emotion, and to ignorance. The second includes begging the question, but we will also discuss various ways in which people seal their positions to make them immune to any possible counterexample. This apparent virtue turns out to be a vice. READING: Understanding Arguments, Ninth Edition, Chapters 15 and 16
Week 12 (March 31 – April 6): Refutation
CONTENT: Not all objections to arguments succeed in refuting those arguments, so this week’s lectures begin by distinguishing objections from refutations. One way to refute an argument is to show that its premises are false, so we will discuss counterexamples and reductio ad absurdum arguments. Another way to refute an argument is to show that its premises do not support its conclusion, which can be accomplished by a method called refutation by parallel reasoning (or “That’s just like arguing …”). The method is a general way to spot fallacies. This closing week brings us back to a theme of the first week, because refutation is another purpose of argument in addition to persuasion, justification, and explanation. READING: Understanding Arguments, Ninth Edition, Chapter 17
QUIZ #4: At the end of Week 12, students will take their fourth quiz.