ROGUES’ GALLERY
OF
VILLAINOUS FALLACIES
By E. Jerome Van Kuiken
Welcome to the Rogues’ Gallery of Villainous Fallacies! In these pages, I’m going to introduce you to a number of dirty, rotten scoundrels of informal logic. They kill critical thinking, maim good discussions, and steal value from both persons and ideas. By studying their profiles, you’ll become an expert detective, able to track down these thugs and lock ‘em up!
Here’s a quick checklist of the fallacies we’ll be profiling:
- Line-Drawing Fallacy
- False Cause
- Hasty Generalization
- Justified Wrongdoing
- Shifting the Burden of Proof
- Appeal to Emotion
- Ad Hominem
- Appeal to (Expert) Authority
- Appeals to Other Authorities & Reverse Appeals
- Straw Man
- Circular Reasoning (Question-Begging)
- Guilt By Association
- Innuendo
- Red Herring
- Spin
- False Dilemma
Grab your magnifying glass and notepad, and let’s enter the gallery!
1. Line-Drawing Fallacy
This fallacy says, “Accept (or reject) this, because it’s only different in degree from what you already accept (or reject).” Take this example: “Eating a candy bar makes me happy. Eating two candy bars should make me happier. And eating three candy bars should make me even happier yet. And eating twenty-five candy bars should make me unbelievably happy.” Of course, if you follow through on this line of reasoning, you’ll end up with an unbelievable stomachache. It may be difficult to draw the line as to just when your happiness peaked and unhappiness set in during your candy bar binge, but no doubt the line is there. Here’s another example: “At what point does a worker officially cross the line into loafing on the job? Is it when they aren’t productive for half a minute? A full minute? Five minutes? Fifteen minutes? Since the line between loafing and non-loafing is so hard to draw, employers shouldn’t fire employees for loafing.” Sounds plausible, right? But I suspect that if you find yourself doing all the work while your co-workers just stand around, then you have a pretty good idea about what constitutes loafing, even if you can’t pin down the precise moment it began.
2. False Cause
This is my handy label for a whole family of fallacies. Their common trait is seeing a cause where it’s not. One member of the family goes by the name Post Hoc Fallacy, from the Latin phrase, post hoc, ergo propter hoc (“after this, so because of this”). When one thing happens after another thing, people may mistakenly think that the first thing made the second thing happen. For over a thousand years, Europeans believed in the spontaneous generation of some types of animals. They were sure that rats, for instance, came from dirty rags. Why? Because they would throw their dirty rags in a corner, and pretty soon they’d notice rats among the rags. But in the 1800’s, the great scientist Louis Pasteur disproved the idea that dirty rags caused rats to exist. Now we take it for granted that, while rats may be attracted by rags, they aren’t produced by rags.
A cousin of the Post Hoc Fallacy is the “Common Traits Prove Common Cause” Fallacy (I’ll let you come up with the Latin name for this one!). You may have heard about the rumored “curse” on the U.S. Presidency: Presidents elected on years ending in zero die in office. Look at the evidence below:
President Election Year Cause of Death*
William Harrison 1840 Natural Causes
Abraham Lincoln 1860 Assassination
James Garfield 1880 Assassination
William McKinley 1900 Assassination
Warren Harding 1920 Natural Causes
Franklin Roosevelt 1940 Natural Causes
John Kennedy 1960 Assassination
Ronald Reagan 1980 Assassination*
(*Reagan survived an assassination attempt, thus breaking the “curse.”)
Should we conclude, then, that being elected in a year ending with zero causes presidential fatalities? No. For one thing, the list of evidence above ignores the fact that another President, Zachary Taylor, died in office, yet he was elected in 1848. The list also neglects to mention that Thomas Jefferson and James Monroe were both elected in years ending in zero, yet they survived their presidencies.
Yet another member of the False Cause family confuses a circumstance with a cause. Just because something happens along with or at the same time as something else, it doesn’t mean the one causes the other. An athlete may be wearing a favorite pair of underwear and also be on a winning streak, but that doesn’t mean the “lucky undies” can take the credit for the wins.
The final False Cause family member I’d like you to meet is the slippery slope fallacy. Imagine a cartoon character on a snowy mountain. The character slips or gets bumped and rolls head over heels down the mountainside, picking up snow along the way until, by the time they reach the bottom of the slope, they’re encased in a giant snowball. That’s the image behind this way of thinking: If you do A, it’ll cause you to end up at Z. Look at two examples of a slippery slope:
If you smoke one cigarette, you’ll end up addicted to cigarettes.
Dating leads to physical involvement, which leads to premarital sex, which leads to unplanned pregnancies; so don’t date!
Not all slippery-slope thinking is fallacious; the question is, Is there good reason to believe that one thing will cause another thing to happen? In the first example above, it is highly likely (though not absolutely guaranteed) that experimenting with cigarettes will lead to a tobacco addiction. The first example, then, is only fallacious if it’s intended to claim that smoking one cigarette must cause addiction; as a statement about what generally happens, though, it’s not fallacious.
What about the second example? For one thing, it depends on your definition of “dating.” If your definition includes sex, then by definition dating leads to sex, just like deciding to boil an egg leads to hot water (and yes, premarital sex leads to hot water, too!). But the standard definition of dating doesn’t include sex. Besides, notice how overstated the sequence is in Example 2: you can date (according to the standard definition) without physical involvement; you can kiss or hold hands without going to bed together; and sex doesn’t always lead to babies. There may be some persons whose background is such that dating is too slippery a slope for them. In that case, they’re wiser to avoid it altogether. But as a comprehensive statement of reality, Example 2 is a fallacy. The causal chain that it claims has too many weak links.
As you can probably tell from some of the examples above, False Cause fallacies are a main ingredient for a witch’s brew of superstitions and conspiracy theories. Establishing a causal relationship isn’t always simple. Take an illustration from history: the ziggurats of the Assyrians and Babylonians and the stepped pyramids of the Maya and Aztecs look a lot alike and all functioned as temples, yet appear on opposite sides of the world, separated by oceans and centuries. How do we account for their similar architecture and purpose? Logically, there are four possible explanations. Either 1. the Old World ziggurats provided the inspiration for the New World pyramids; or 2. the reverse is true, and the pyramid-builders influenced the ziggurat-builders; or 3. both share a common source (UFOs? Refugees from Atlantis?); or 4. there is no causal connection: the similarities are coincidental. When you’re trying to figure out causes, it’s important to keep all the possible connections in mind.
3. Hasty Generalization
Suppose the family dentist you visited while you were growing up always smiled and laughed a lot. Would you be justified in assuming that dentists in general are smiley and laugh a lot? What if your high school hosted three foreign exchange students from, say, South Korea, and this trio of Koreans were all very smart, very wealthy, and very stuck up? Should you reasonably conclude that all Koreans, or even all Asians or all foreigners, share those characteristics?
The answer is No. The reason is that your sample (of dentists or of Koreans) is too small for you to generalize that the whole group is like the sample. Instead of hastily jumping to conclusions about dentists or Koreans as a whole, you need to hold off until you get a larger sample. Maybe your dentist just inhaled too much laughing gas! In the case of the Koreans, the fact that they are foreign exchange students helps explain why all three are smart: you aren’t likely to be allowed to study abroad if your grades are lousy.
Hasty generalization can lead to prejudice against various groups of people. Hasty generalization can also be used by advertisers to manipulate you into buying their products. For instance, suppose an ad claims, “Nine out of ten doctors surveyed recommend X-Zit acne removal cream to their patients.” Wow! It sounds like most doctors think X-Zit is a really good product, right? Wait a minute, though: notice the word surveyed in the script. What the ad doesn’t tell you is how many doctors were surveyed, or where these doctors are. Suppose only ten doctors were surveyed. Or suppose X-Zit is manufactured in Louisville, Kentucky, and that all the doctors surveyed practice medicine in Louisville. In either of these cases, the sampling of doctors is far too small for you to conclude that most doctors recommend X-Zit.
4. Justified Wrongdoing
Suppose you’re a Senator who’s been charged by your colleagues with seducing female interns. What do you do? Here’s a quick playbook of responses:
1. Accuse your accusers of doing the same thing – or worse: “My fellow Americans, some of the Senators who are accusing me have divorced their wives in order to marry their mistresses. Besides, these same Senators have voted against tougher laws against child pornography. How can they attack my weakness for women when they won’t even defend helpless children?”
2. Calculate that two wrongs make a right: “The American people should know that my wife has had a string of affairs, so I felt justified in evening the score.”
3. Use double standards: “Of course it was wrong when Bill Clinton had that ‘inappropriate relationship’ with Monica, but he was the President, for goodness’ sake. His conduct reflects on America and all Americans. I’m just a Senator. What I do reflects only on myself.”
4. Appeal to the ends to justify the means: “The Senate is holding hearings on the decline in morality among American youth, so I was just doing some personal research.”
What all of these responses have in common is that they try to downplay or distract from the bottom line: the action in question was wrong. It’s wrong whether the people around you, including your accusers, do right or wrong; it’s wrong whatever your motives, status, or uprightness on other issues may be; it’s simply wrong. To see that this is so, try this thought experiment: If one of the interns were your sister or daughter or girlfriend, would you accept any of the Senator’s responses above?
5. Shifting the Burden of Proof
Picture a pair of scales. These scales weigh the likelihood of a belief being true. If the scales are tipped far to the left by the number of people who hold to a belief, or by good evidence for a belief, then someone who doesn’t share that belief is going to have to give some very weighty reasons in order to tip the scales in their favor. The burden of proof is on the one who doesn’t share the accepted belief. If, however, the scales are evenly balanced, meaning that public opinion or expert opinion is divided or that there’s good evidence both ways, then both sides share equally the burden of proof: both sides have to work just as hard to defend their claims. One fallacious method of reasoning is to unfairly shift the burden of proof so that one side doesn’t have to work as hard as it should. Suppose a philosopher demands that you prove that you exist. You have every right to respond, “Prove that I don’t exist!” The burden of proof lies on the philosopher’s side of the scales, not yours.
One way to unfairly shift the burden of proof is called the argument from ignorance. If we don’t know (or can’t prove) that something’s false, does that mean it’s true? That’s what the argument from ignorance claims. It’s like someone saying, “No one’s ever proved that Bigfoot doesn’t exist, so I’m justified in believing in Bigfoot.” Really, the burden of proof is on those who believe Bigfoot exists to prove it, not on those who don’t believe to disprove it.
An extreme form of the argument from ignorance is an untestable claim. This is a claim that it’s impossible to ever test or disprove. Here’s an example: “You have been hypnotized. Every thought you have is being controlled by a master brainwasher.” How would you go about refuting such a claim? Anything you think, say, or do to try to test or disprove the claim may just be the hypnotist toying with you.
For a belief to usefully be considered true, it must be falsifiable – that is, it must be capable of being tested so that, if it’s false, it can be proven false. Even religious truth-claims should be falsifiable. In 1 Corinthians 15, the Apostle Paul gave support for his claim that Jesus Christ had been raised from the dead. Then Paul wrote, “And if Christ has not been raised, our preaching is useless and so is your faith.” (v. 14 NIV) For Paul, it did no good to believe in Christ’s resurrection if that belief was contrary to fact. Belief in the Resurrection is falsifiable, not because it’s false, but because we can test it to see if it’s true or false: find Jesus’ bones, and Christianity is disproved.
6. Appeal to Emotion
One easy way to avoid giving a rational argument is by substituting feelings for facts. Consider the range of emotions you can play upon: