Fallacies
Fallacies are assertions that violate the accepted standards of valid argument. Fallacious claims are not the same as false claims, though fallacies are often based on falsities. A fallacy is an assertion that is stated sloppily or, as the case may be, with the intent to sell an idea deceptively. Some fallacies occur when the writer--the claimant--has simply (out of laziness, a cocksure bias, or whatever reason) not researched the idea well enough. Some understanding of these defective ways of reasoning is important for writers so they can avoid using them. It is important that citizens understand them so they will learn to recognize faulty or deceptive reasoning. Argument is often complex and occurs in many different contexts. There are some argumentative contexts in which fallacies are less frowned upon than others. We need to be able to identify fallacies, but we should, as Andrea Lunsford writes, "be cautious in jumping to conclusions about them. Rather than thinking of them as errors you can root out and use to discredit an arguer, you might think of them as barriers to common ground and understanding, since they so often shut off rather than engender debate."
What follows are some of the more prevalent fallacies. There are many more that we don't have the space to cover. For more information on fallacies, see Edward P. J. Corbett's Classical Rhetoric for the Modern Student, a book to which this page is indebted for many of its ideas.
Either/Or fallacy: This fallacy occurs when a speaker or writer presents the audience with two false choices: "Either this or that." Not everything in the world is right or wrong, black or white, good or evil, democratic or undemocratic, and so on. There are, of course, several issues and ideas that do involve precisely two realities--one is either pregnant or one is not--but other times an either/or statement fails to account for all possibilities in a given situation. Those who commit this fallacy fail to account for the complexity of an idea, sometimes purposely, in order to force adherence to an agenda. For example, to state that everyone is either for immigration or against is to oversimplify: one may be in favor of open borders in virtually all (or no) cases, for temporary work, or hold any one of a wide variety of other positions.
Faulty (or hasty) generalization: One engages in a faulty generalization when the scope of the evidence is too small or the quality of it is too poor to support the conclusion. In his only trip by car through St. Louis, Joe witnesses the aftermath of the worst car wreck (involving several vehicles and injuries) he's seen in his life. If, upon arriving home, Joe concludes that St. Louis is the most dangerous city in the U.S. in which to drive, he has committed a hasty generalization. In order to justify such a claim, one would probably need to consult reliable, recent data on automobile accident rates in U.S. metropolitan areas.
Post hoc, ergo propter hoc (Latin for "after this, therefore because of this"): This fallacy assumes that a time relationship is the same as a causal one, that precedence is indistinguishable from cause. One of the most common (albeit light) instances of this fallacy occurs when one complains that a rainstorm occurs because one has just washed his car. Similarly, the claim that a sharp sales increase in a brand of computers is due to the buying public's fondness for a company spokesperson on TV may well be an instance of a post hoc, ergo propter hoc fallacy. Some amount of credible research would be required to determine the veracity of such a claim.
Begging the question: Begging the question occurs when the claim one makes holds assumptions about its own truthfulness or when a claim carries an idea that is itself positioned on questionable grounds. For example, the question-assertion (common in papers by younger students), "What has led to the current breakdown in the morals of contemporary society?" begs the questions, "In what ways, by what standards, have morals 'broken down' in society?" "How do you know; how can you measure and confirm this?" Some assertions ("Reading and writing improve one's mind") are givens, but others ("Schools are more violent now than ever before") are not and must be proven, at least provisionally.
Argument ad hominem: This phrase means "to the man" and is one of the most common fallacies in the public sphere today. To commit an ad hominem fallacy (or attack) is to criticize someone not on the substance of what he or she says but on the personality of the person who says it. In other words, to attack someone ad hominem is to attack that person's character. Of course, character can have relevance to an argument, but when such an attack is used to cloud the issue and distract from rational discourse, one is committing an ad hominem fallacy. When actors and musicians are criticized for having opinions about social or political issues ("He doesn't know what he's talking about. After all, he's a singer, not political analyst"), it won't do to simply dismiss their remarks because they are "mere entertainers." Talk radio and tabloid-style media largely thrive on the ad hominem attack. Careful thinkers will spot and denounce such tactics as invalid and, in some cases, reprehensible.
Argument ad populum: Meaning "to the people," this fallacy (similar to the ad hominem attack) occurs when one appeals to peoples' irrational fears and prejudices as a way of preventing them from directly facing issues. Thus, if an Arkansan says to another Arkansan, "That speaker is full of bull. He is a Northerner," he is relying on a ready-made attitude that appeals to (what at least he assumes to be) a shared suspicion of a certain group of people. Another way of committing an ad populum fallacy is by employing recklessly connotative terms in order to stir the emotions of a certain group of people. Today in the U.S., for example, words such as "patriotic" and "pro-family" stir a positive emotional climate for some audiences, while words such as "socialism" and "feminist" are often used to stir up irrational anger. People who think for themselves question the use of such words and phrases as ready-made codes, as instructions on how and what to think (e.g., one might conclude that patriotism is of course a good thing but that real patriots have an obligation to question authority and to reject the notion of "My country, right or wrong" as dangerous, totalitarian rubbish).
The Red Herring: This strangely-titled fallacy, named after a strong-smelling fish (the scent of which throws hounds off the scent of a trail), occurs when one draws attention away from the main issue in a given case by focusing on a side issue or on something irrelevant. Accused of deceptive accounting practices, some in Enron's accounting firm, Arthur Anderson, replied that their practices are the norm in all accounting firms. This claim may or may not be true, but it is a red herring because it attempts to draw fire away from Arthur Anderson and Enron and toward the larger profession of accountants. Another way to see the red herring is as a changing of the subject. (Most married couples know a lot about the red herring!)
Others, in brief:
Latin for "it does not follow," a non sequitur is an inference that
doesn't follow from the premises. In a sense, every fallacy is a non
sequitur, an attempt to pass off two or more ideas as related though they are in
fact not related (e.g., "If we can send a man to the moon, why can't we find a
cure for the common cold?").
The appeal to traditional wisdom justifies something by stating, "We've
always done it that way." Shirley Jackson's famous story "The Lottery" is
a dramatic, eloquent repudiation of this fallacy.
A strawman (or strawperson) fallacy occurs when one changes an opponent's argument, often
by focusing on a weakened version of the argument (e.g., "My opponent wants to
free serial killers and kidnappers, but I believe in laws that favor the rights
of victims"). A straw man is, of course, easier to dissemble than a
real man.
The bandwagon appeal suggests that a great movement is underway and makes the reader feel guilty or foolish if he or she has not become a part of it (e.g., "Over 60% of the city's residents believes he is a doing a satisfactory job as mayor, so your unfavorable opinion of him is discredited").