Chapter 5: Informal Fallacies II
Essential Logic Ronald C. Pine Chapter 5: Informal Fallacies II Reasoning is the best guide we have to the truth....Those who offer alternatives to reason are either mere hucksters, mere claimants to the throne, or there's a case to be made for them; and of course, that is an appeal to reason. Michael Scriven, Reasoning Why don’t you ever see a headline, “Psychic wins lottery”? Internet Joke News Item, June 16, 2010: A six story statue of Jesus in Monroe city, Ohio was struck by lightning and destroyed. An adult book store across the street was untouched. Introduction In the last chapter we examined one of the major causes of poor reasoning, getting off track and not focusing on the issues related to a conclusion. In our general discussion of arguments (Chapters 1-3), however, we saw that arguments can be weak in two other ways: 1. In deductive reasoning, arguments can be valid, but have false or questionable premises, or in both deductive and inductive reasoning, arguments may involve language tricks that mislead us into presuming evidence is being offered in the premises when it is not. 2. In weak inductive arguments, arguments can have true and relevant premises but those premises can be insufficient to justify a conclusion as a reliable guide to the future. Fallacies that use deductive valid reasoning, but have premises that are questionable or are unfair in some sense in the truth claims they make, we will call fallacies of questionable premise. As a subset of fallacies of questionable premise, fallacies that use tricks in the way the premises are presented, such that there is a danger of presuming evidence has been offered when it has not, we will call fallacies of presumption.
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