Logical fallacies are arguments that rely on faulty reasoning, though the surface of the argument may be appealing to an uncritical audience. They can be categorized broadly into three different types: fallacies of ethos, pathos, and logos.
Here are some common examples of logical fallacies:
Fallacies of Ethos (Character)
Ad hominem
Attacking the person making an argument rather than the argument itself.
Example: “Of course that doctor advocates vaccination—he probably owns stock in a pharmaceutical company.”
False authority
Relying on claims of expertise when the claimed expert (a) lacks adequate background/credentials in the relevant field, (b) departs in major ways from the consensus in the field, or (c) is biased, e.g., has a financial stake in the outcome.
Example: “Dr. X is an engineer, and he doesn’t believe in global warming.”
Guilt by association
Linking the person making an argument to an unpopular person or group.
Example: “My opponent is a card-carrying member of the ACLU.”
Poisoning the well
Undermining an opponent’s credibility before he or she gets a chance to speak.
Example: “The prosecution is going to bring up a series or so-called experts who are getting a lot of money to testify here today.”
Transfer fallacy
Associating the argument with someone or something popular or respected; hoping that the positive associations will “rub off” onto the argument.
Examples: In politics, decorating a stage with red, white, and blue flags and bunting; in advertising, using pleasant or wholesome settings as the backdrop for print or video ads.
Name-calling
Labeling an opponent with words that have negative connotations in an effort to undermine the opponent’s credibility.
Example: “These rabble-rousers are nothing but feminazis.”
Plain folk
Presenting yourself as (or associating your position with) ordinary people with whom you hope your audience will identify; arguers imply that they or their supporters are trustworthy because they are ‘common people’ rather than members of the elite.
Example: “Who would you vote for—someone raised in a working-class neighborhood who has the support of Joe the Plumber or some elitist whose daddy sent him to a fancy school?”
Testimonial fallacy
Inserting an endorsement of the argument by someone who is popular or respected but who lacks expertise or authority in the area under discussion.
Example: “I’m not a doctor, but I play one on TV”—a famous example of a celebrity endorsement for a cough syrup (Deis, 2011, n.p.).
Fallacies of Pathos (Emotion)
Appeal to fear
Using scare tactics; emphasizing threats or exaggerating possible dangers.
Example: “Without this additional insurance, you could find yourself broke and homeless.”
Appeal to guilt or pity
Trying to evoke an emotional reaction that will cause the audience to behave sympathetically even if it means disregarding the issue at hand.
Example: “I know I missed assignments, but if you fail me, I will lose my financial aid and have to drop out.”
Appeal to popularity (bandwagon)
Urging audience to follow a course of action because “everyone does it.”
Example: “Nine out of ten shoppers have switched to Blindingly-Bright-Smile Toothpaste.”
Slippery Slope
Making an unsupported or inadequately supported claim that “One thing inevitably leads to another.” This may be considered a fallacy of logos as well as pathos but is placed in this section because it often is used to evoke the emotion of fear.
Example: “We can’t legalize marijuana; if we do, then the next thing you know people will be strung out on heroin.”
Appeal to the people
(Also called a stirring symbols fallacy): The communicator distracts the readers or listeners with symbols that are very meaningful to them, with strong associations or connotations.
Example: This fallacy is referred to in the sentence “That politician always wraps himself in the flag.”
Appeal to tradition
People have been done it a certain way for a long time; assumes that what has been customary in past is correct and proper.
Example: “A boy always serves as student-body president; a girl always serves as secretary.”
Loaded-Language (emotionally charged uses of language)
Using slanted or biased language, including God terms, devil terms, euphemisms, and dysphemisms.
Example: In the sentence “Cutting access to food stamps would encourage personal responsibility,” the god term is “personal responsibility.” It might seem as if it would be hard to argue against “personal responsibility” or related god terms such as “independence” and “self-reliance.” However, it would require a definition of “personal responsibility,” combined with evidence from studies of people’s behavior in the face of food stamp or other benefit reductions, to argue that cutting access to food stamps would lead to the intended results.
Fallacies of Logos (Logic)
Hasty generalization
Jumping to conclusions based upon an unrepresentative sample or insufficient evidence.
Example: “10 of the last 14 National Spelling Bee Champions have been Indian American. Indian Americans must all be great spellers!”
Appeal to ignorance—true believer’s form
Arguing along the lines that if an opponent can’t prove something isn’t the case, then it is reasonable to believe that it is the case; transfers the burden of proof away from the person making the claim (the proponent).
Example: “You can’t prove that extraterrestrials haven’t visited earth, so it is reasonable to believe that they have visited earth.”
Appeal to ignorance—skeptic’s form
Confusing absence of evidence with evidence of absence; assumes that if you cannot now prove something exists, then it is shown that it doesn’t exist.
Example: “There’s no proof that starting classes later in the day will improve the performance of our high school students; therefore, this change in schedule will not work.”
Begging the question
Circular argument because the premise is the same as the claim that you are trying to prove.
Example: “This legislation is sinful because it is the wrong thing to do.”
False dilemma
Misuse of the either/or argument; presenting only two options when other choices exist
Example: “Either we pass this ordinance or there will be rioting in the streets.”
Post hoc ergo propter hoc
Latin phrase meaning “after this, therefore because of this”; confuses correlation with causation by concluding that an event preceding a second event must be the cause of that second event.
Example: “My child was diagnosed with autism after receiving vaccinations. That is proof that vaccines are to blame.”
Non-sequitur
Latin for “does not follow”; the conclusion cannot be inferred from the premises because there is a break in the logical connection between a claim and the premises that are meant to support it, either because a premise is untrue (or missing) or because the relationship between premises does not support the deduction stated in the claim.
Example (untrue premise): “If she is a Radford student, she is a member of a sorority. She is a Radford student. Therefore she is a member of a sorority.”
Smoke screen
Avoiding the real issue or a tough question by introducing an unrelated topic as a distraction; sometimes called a red herring.
Example: “My opponent says I am weak on crime, but I have been one of the most reliable participants in city council meetings.”
Straw man
Pretending to criticize an opponent’s position but actually misrepresenting his or her view as simpler and/or more extreme than it is and therefore easier to refute than the original or actual position; unfairly undermines credibility of claim if not source of claim.
Example: “Senator Smith says we should cut back the Defense budget. His position is that we should let down our defenses and just trust our enemies not to attack us!”
Conclusion
Fallacies can crop up whenever definitions, inferences, and facts are at issue. Once we become familiar with fallacies we may start to see them everywhere. That can be good and bad. Since persuasion is ever-present, it is good to be on guard against various hidden persuaders.
But whether a persuasive strategy is considered fallacious may be dependent on context.
Editorials and advertisements—both political and commercial—frequently use such strategies as transfer and appeals to popularity. We need to be critically aware of the techniques of persuasion being used on us, but since we expect advertisements, political speeches, and editorials on public policy or ethical issues to try to sway us emotionally, perhaps only extreme examples deserve to be judged harshly for being fallacious.
In addition, something that looks as if it is a fallacy may turn out not to be on closer examination.
For example, not everything that smacks of slippery slope is fallacious. There are indeed some genuine slippery slopes, where an initial decision or action may have both great and inevitable repercussions. So whether that fallacy has been committed depends upon what the author has done (or failed to do) to support his claim.
Similarly, while personal attacks (ad hominem) in most cases are unfair and considered fallacious, there are special situations in which a person’s character may be directly relevant to his or her qualifications. For example, when somebody is running for political office or for a judgeship, casting doubt on his or her character may be appropriate—if one has facts to back it up—since it relates to job expectations. But wholesale character assassination remains a rhetorical ploy of the propagandist or demagogue.
Attribution