Fallacies [Internet Encyclopedia of Philosophy] http://www.iep.utm.edu/fallacy/ Internet Encyclopedia of Philosophy A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Fallacies A fallacy is a kind of error in reasoning. The alphabetical list below contains 195 names of the most common fallacies, and it provides brief explanations and examples of each of them. Fallacies should not be persuasive, but they often are. Fallacies may be created unintentionally, or they may be created intentionally in order to deceive other people. The vast majority of the commonly identified fallacies involve arguments, although some involve explanations, or definitions, or other products of reasoning. Sometimes the term “fallacy” is used even more broadly to indicate any false belief or cause of a false belief. The list below includes some fallacies of these sorts, but most are fallacies that involve kinds of errors made while arguing informally in natural language. The discussion that precedes the list begins with an account of the ways in which the term “fallacy” is vague. Attention then turns to the number of competing and overlapping ways to classify fallacies of argumentation. For pedagogical purposes, researchers in the field of fallacies disagree about the following topics: which name of a fallacy is more helpful to students’ understanding; whether some fallacies should be de-emphasized in favor of others; and which is the best taxonomy of the fallacies. Researchers in the field are also deeply divided about how to define the term “fallacy” itself, how to define certain fallacies, and whether any theory of fallacies at all should be pursued if that theory’s goal is to provide necessary and sufficient conditions for distinguishing between fallacious and non-fallacious reasoning generally. Analogously, there is doubt in the field of ethics regarding whether researchers should pursue the goal of providing necessary and sufficient conditions for distinguishing moral actions from immoral ones. Table of Contents Introduction Taxonomy of Fallacies Pedagogy What is a fallacy? Other Controversies Partial List of Fallacies References and Further Reading 1. Introduction The first known systematic study of fallacies was due to Aristotle in his De Sophisticis Elenchis (Sophistical Refutations), an appendix to the Topics. He listed thirteen types. After the Dark Ages, fallacies were again studied systematically in Medieval Europe. This is why so many fallacies have Latin names. The third major period of study of the fallacies began in the later twentieth century due to renewed interest from the disciplines of philosophy, logic, communication studies, rhetoric, psychology, and artificial intelligence. The more frequent the error within public discussion and debate the more likely it is to have a name. That is one reason why there is no specific name for the fallacy of subtracting five from thirteen and concluding that the answer is seven, though the error is common among elementary school children. The term “fallacy” is not a precise term. One reason is that it is ambiguous. It can refer either to (a) a kind of error in an argument, (b) a kind of error in reasoning (including arguments, definitions, explanations, and so forth), (c) a false belief, or (d) the cause of any of the previous errors including 1 of 31 17/10/10 7:22 AM Fallacies [Internet Encyclopedia of Philosophy] http://www.iep.utm.edu/fallacy/ what are normally referred to as “rhetorical techniques.” Philosophers who are researchers in fallacy theory prefer to emphasize (a), but their lead is often not followed in textbooks and public discussion. Regarding (d), ill health, being a bigot, being hungry, being stupid, and being hypercritical of our enemies are all sources of error in reasoning, so they could qualify as fallacies of kind (d), but they are not included in the list below. On the other hand, wishful thinking, stereotyping, being superstitious, rationalizing, and having a poor sense of proportion are sources of error and are included in the list below, though they wouldn’t be included in a list devoted only to faulty arguments. Thus there is a certain arbitrariness to what appears in lists such as this. What have been left off the list below are the following persuasive techniques commonly used to influence others and to cause errors in reasoning: apple polishing, assigning the burden of proof inappropriately, using propaganda techniques, ridiculing, being sarcastic, selecting terms with strong negative or positive associations, using innuendo, and weasling. All of the techniques are worth knowing about if one wants to avoid the fallacies. In describing the fallacies below, the custom is followed of not distinguishing between a reasoner committing a fallacy and the reasoning itself committing the fallacy, though it would be more accurate to say that a reasoner commits the fallacy and the reasoning contains the fallacy. In the list below, the examples are very short. If they were long, the article would be too long. Nevertheless real arguments are often embedded within a very long discussion. Richard Whately, one of the greatest of the 19th century researchers into informal logic, wisely said, “A very long discussion is one of the most effective veils of Fallacy; …a Fallacy, which when stated barely…would not deceive a child, may deceive half the world if diluted in a quarto volume.” 2. Taxonomy of Fallacies There are a number of competing and overlapping ways to classify fallacies of argumentation. For example, they can be classified as either formal or informal. A formal fallacy can be detected by examining the logical form of the reasoning, whereas an informal fallacy depends upon the content of the reasoning and possibly the purpose of the reasoning. That is, informal fallacies are errors of reasoning that cannot easily be expressed in our system of formal logic (such as symbolic, deductive, predicate logic). The list below contains very few formal fallacies. Fallacious arguments also can be classified as deductive or inductive, depending upon whether the fallacious argument is most properly assessed by deductive standards or instead by inductive standards. Deductive standards demand deductive validity, but inductive standards require inductive strength such as making the conclusion more likely. Fallacies can be divided into categories according to the psychological factors that lead people to commit them, and they can also be divided into categories according to the epistemological or logical factors that cause the error. In the latter division there are three categories: (1) the reasoning is invalid but is presented as if it were a valid argument, or else it is inductively much weaker than it is presented as being, (2) the argument has an unjustified premise, or (3) some relevant evidence has been ignored or suppressed. Regarding (2), a premise can be justified or warranted at a time even if we later learn that the premise was false, and it can be justified if we are reasoning about what would have happened even when we know it didn’t happen. Similar fallacies are often grouped together under a common name intended to bring out how the fallacies are similar. Here are three examples. Fallacies of relevance include fallacies that occur due to reliance on an irrelevant reason. In addition, ad hominem, appeal to pity, and affirming the consequent are some other fallacies of relevance. Accent, amphiboly and equivocation are examples of fallacies of ambiguity. The fallacies of illegitimate presumption include begging the question, false dilemma, no true Scotsman, complex question and suppressed evidence. Notice how these categories don’t fall neatly into just one of the categories (1), (2), and (3) above. 3. Pedagogy It is commonly claimed that giving a fallacy a name and studying it will help the student identify the fallacy in the future and will steer them away from committing the fallacy in their own reasoning. As Steven Pinker says in The Stuff of Thought (p. 129), If a language provides a label for a complex concept, that could make it easier to think about the concept, because the mind can handle it as a single package when juggling a set of ideas, rather than having to keep each of its components in the air separately. It can also give a concept an additional label in long-term memory, making it more easily retrivable than ineffable concepts or those with more roundabout verbal descriptions. For pedagogical purposes, researchers in the field of fallacies disagree about the following topics: which name of a fallacy is more helpful to students’ understanding; whether some fallacies should be de-emphasized in favor of others; and which is the best taxonomy of the fallacies. Fallacy theory is criticized by some teachers of informal reasoning for its over-emphasis on poor reasoning rather than good reasoning. Do colleges teach the Calculus by emphasizing all the ways one can make mathematical mistakes? The critics want more emphasis on the forms of good arguments and on the implicit rules that govern proper discussion designed to resolve a difference of opinion. But there has been little systematic study of which emphasis is more successful. 4. What is a fallacy? Researchers disagree about how to define the very term “fallacy.” Focusing just on fallacies in sense (a) above, namely fallacies of argumentation, some researchers define a fallacy as an argument that is deductively invalid or that has very little inductive strength. Because examples of false dilemma, inconsistent premises, and begging the question are valid arguments in this sense, this definition misses some standard fallacies. Other researchers say a fallacy is a mistake in an argument that arises from something other than merely false premises. But the false dilemma fallacy is due to false premises.