24 Arguments X: Fallacies in Reasoning
We now turn to some of the common problems we face in reasoning. In this chapter we’ll focus on a number of what are called fallacies.
- A fallacy, broadly understood, is an error in reasoning.
- A fallacious argument is one that commits a fallacy.
Generally, fallacies are broken down into two main categories:
- Formal Fallacy: a formal fallacy is an error in deductive argumentation that makes an argument invalid.
- Note: We’ve seen two formal fallacies already: those invalid argument patterns 3 and 4 on the chart of argument patterns in the previous chapter.
- Informal Fallacy: an informal fallacy occurs when the premises in an argument (either deductive or inductive) either fail to provide adequate support for the conclusion, or when the premises are in some way irrelevant to the conclusion. Informal fallacies also occur in less structured speech and writing when we’re not directly making arguments.
- Note 1: “Informal” here does not mean “casual,” although there are many casual conversational (or written) situations in which there’s no attempt at clearly stating an argument, but in which informal fallacies nevertheless occur.
- Note 2: We’ve already seen two informal fallacies: Hasty Generalization and Faulty Analogy. These are the names given to inductive generalizations and analogies when the premises don’t provide adequate support for the conclusion.
We won’t look at formal fallacies any more than we already have (i.e., beyond the two invalid patterns on the chart in the previous chapter). Instead we’ll focus on a few common informal fallacies. These are ways in which we frequently mess up when we are reasoning in both everyday and academic situations.
If you learn these, you will be able to avoid them in your own reasoning, and you will be better able to assess how well other people are reasoning. As it happens, these fallacies are particularly common in advertising and in political discourse – so by knowing them, you will be able to recognize when someone is trying to manipulate you. (And if you so choose, you can use your new knowledge of these to manipulate others who haven’t learned them. I like to think of this as a class in what you Harry Potter fans will know as Defense against the Dark Arts, but, if you are more inclined towards Slytherin than towards Gryffindor, it can be used as one in how to practice the Dark Arts as well. You will not, however, learn the Unforgivable Fallacies here, as then I would lose my job.)
Here is a chart with the eight fallacies we’ll focus on.
| Name | Definition | Examples | Notes |
| 1. Genetic Fallacy | Arguing that a claim is true or false solely because of its origin. | 1. Don’t believe it when the Wall Street Journal reports that lowering taxes will boost economic growth. It always says whatever the Republicans want it to.
2. Don’t believe it when National Public Radio reports that lowering taxes will increase inequality. It has a known liberal bias and is always in favor of redistributing wealth. |
Here origin (or source) = an impersonal institution, organization, etc., not a specific person or set of identifiable individuals.
Note also that “genetic” has nothing to do with DNA here – it just refers to origins (the genesis of something is its source or origin) |
| 2. Appeal to the Person (ad hominem) | Rejecting a claim by criticizing the person who makes it rather than the claim itself (or accepting a claim because of who’s making it). This often takes the form of a charge of hypocrisy (saying one thing but doing the opposite), a personal attack (insult), or pointing out a conflict of interest (e.g., that someone benefits financially if what they are saying is true). | 1. Don’t listen to him when he says it’s ok to eat meat. For he’s mean and just likes to see animals suffer.
2. Don’t listen to her when she says smoking is bad for you. She smokes two packs a day! 3. The doctors who say prescription anti-depressants are the most effective treatment for depression can’t be trusted. For they are all paid consultants for the companies who make the drugs. |
Here source = a specific individual or identifiable set of individuals.“Ad hominem” is a Latin phrase (given to this fallacy by logicians centuries ago) meaning at or to the person. You’ll often hear it called this. |
| 3. Red Herring | The deliberate raising of an irrelevant issue during an argument | You say that factory farming of chickens is cruel and makes them suffer. But have you had the wings at Buffalo Wild Wings? They are sooo delicious. | Just as the smell of a stinky fish will lure a dog away from the scent of the fox, so too can a distracting premise lead you to a conclusion you wouldn’t otherwise arrive at.
Make sure to rule out other fallacies before concluding it’s this one, since there are many fallacies that introduce something irrelevant |
| 4. Straw Man | The distorting, weakening, or oversimplifying of someone’s position so it can be more easily attacked or refuted (or too easily accepted). | Some say that fast-food workers are underpaid. But it’s ridiculous to insist that everyone should make as much as a doctor, no matter what kind of work they do. | This is often confused with Red Herring. |
| 5. Begging the Question | The attempt to establish the conclusion of an argument by using that conclusion as a premise | 1. God guarantees that the Bible is true. The Bible says that God exists. Therefore, God exists.
2. Free trade will help our country and our trading partners as well. For the unimpeded exchange of goods across borders benefits all involved. |
Often this involves stating the same idea using different words, as in the second example: “free trade” and “the unimpeded exchange of goods across borders” mean basically the same thing. |
| 6. False Dilemma | Asserting that there are only two alternatives to consider when there are actually more than two | Either the government gives food to those who are food-insecure, or they don’t get enough to eat. | Look for either-or statements. (Not all dilemmas are false, however. Sometimes there really are just two choices.) |
| 7. Hasty Generalization | Drawing a conclusion about a target group based on an inadequate sample size | I had a Subaru that constantly had problems. I’ll never buy one of them again. Those cars are all junk. | Here the claim is about all or most members of a group (the target group) based on what is known about one or only a very few of them (the sample group). |
| 8. Faulty Analogy | An argument in which the things being compared are not sufficiently similar in relevant ways to justify a conclusion drawn on the basis of comparing them. | My car is a station wagon, has 4-wheel drive, is grey, and has a lot of rust. That car is a grey, 4-wheel drive station wagon. It probably has a lot of rust too. | This is sometimes confused with Hasty Generalization, but here there isn’t a relation between a large group and some members of that group. |
How do you decide which one you’ve got (if any)? When confronted with a passage that might have a fallacy, here are some questions to ask:
- Is there any attempt to direct your attention towards the source of a claim, rather than the truth of the claim itself? If so, it’s probably appeal to the person or genetic fallacy (and the difference then is whether the source is a specific person or group of identifiable individuals, or an impersonal organization or institution).
- Is there overblown and emotional language? If so, there’s a good chance it’s appeal to the person or straw man (and the difference there is whether the focus is on the person making the claim, or whether it misrepresents the claim they make).
- Is the same thing said in different ways, once as a premise then again as the conclusion? If so, then you’ve found a common form of begging the question.
- Are two things being compared and a conclusion drawn that isn’t warranted by the comparison? Then you’ve got a faulty analogy.
- Is a claim about a large group being made based on a very small or unrepresentative subset of that group? If so, then you’ve got a hasty generalization.
- Is there either a stated or implied either-or claim that leaves out a third possibility? If so, you’ve got a false dilemma.
There are lots more named fallacies than the eight listed above (some of those get further divided and have more specific names). Here are a couple of websites (found via Google – you can easily find more) that you can go to if you want to know more, or get more examples (note that different people categorize fallacies in slightly different ways; for homework and quiz purposes, you’ll need to follow the definitions and examples as I’ve given them in the chart above):
http://www.fallacyfiles.org/taxonomy.html
http://www.logicalfallacies.info/
http://www.txstate.edu/philosophy/resources/fallacy-definitions.html
