Author: Michael Sigler
- Introduction
In logic, a fallacy is an error in reasoning. In other words, the reasons given don’t logically
support the conclusion. An informal fallacy is a fallacy due to the content of the argument. So,
when an argument commits an informal fallacy, the argument’s content—what it’s about—fails
to support the conclusion. There are hundreds of informal fallacies. But we won’t cover them
all! Below are some informal fallacies. Let’s turn to them now. - Informal Fallacies
Ad Hominem
An ad hominem fallacy occurs when someone criticizes the person, their character or associates,
rather than their argument or view. Here’s an example:
John’s an idiot! How could you accept his views on counterculture!
John’s character is irrelevant to whether his claims about counterculture are true, interesting, or
valuable. That depends on the claims themselves.
Now, there is an important exception to this. If the argument or issue is about someone’s
character, then claims about their character are relevant. For example,
Hitler was evil. He beat his wife and ordered the annihilation of Jewish people.
Notice that claims about who Hitler was are relevant to the conclusion that he was evil. So, no ad
hominem was fallacy was committed. An ad hominem fallacy occurs when claims about the
person are irrelevant to the issue at hand.
Hasty Generalization
A hasty generalization occurs when someone draws a generalization from insufficient evidence.
A generalization is a claim made about a group of something that is meant to apply to at least
most of the units of that group. If one doesn’t have good evidence to draw that generalization,
it’s hasty. An example:
Pit bulls are all terrible! I know this because the pit bull down the street is nasty to me.
The generalization here is about pit bulls. The property that is meant to apply to most pit bulls is
that they are terrible. But, of course, just because one pit bull is nasty doesn’t show most are.
What the proponent of this argument needs to establish is that a lot of put bulls are nasty.
Red Herring
A red herring is a distraction. It’s used to throw people off track of the central issue. Usually,
when one commits the red herring fallacy, they throw out information that is not directly relevant
to the issue at hand but nevertheless confuses others or leads them away from their central claim.
Here’s an example:
Person A: Bill Clinton’s economic policies in the 90s lead to a stronger country.
Person B: Hmm. He wasn’t very uniting. He cheated on his wife many times over the
years.
Person A: Well, sure, I just think there are merits to his presidency.
Person B: He also threw Monica Lewinsky under the bus to save himself.
Person A: Yeah, I guess.
Person B here is not addressing the economic merits of Bill Clinton’s policies but noting several
times how Clinton was shameless. Person A eventually, though weakly, agrees. But that wasn’t
the topic at hand. Pointing out that Clinton was scummy in his personal life doesn’t demonstrate
anything wrong with his economic policies.
Begging the Question/Circular Reasoning
If someone begs the question, they are assuming the truth (or falsity) of what’s in question. In an
argument, the premises will assume the conclusion is true. But, of course, the point of an
argument is to demonstrate or prove the conclusion is true, not assume it.
Note that the phrase ‘begging the question’ in everyday life usually means to raise the question.
In reasoning, however, it means that one is assuming what’s in question without providing
evidence.
Here are some examples:
Nobody has free will because free will does not exist.
Liberty is good because freedom is good.
Free trade is good, for unconstrained exchange of goods between countries is a good.
In each of these arguments the conclusion and premise mean the same thing. So, the premises
don’t provide any evidence their conclusions are true.
Here’s a more complicated, textbook example:
God exists. I know this because the religious book says so. And God wrote it and
wouldn’t lie.
The conclusion is ‘God exists.’ But the premise that God wrote it assumes God exists to begin
with. Therefore, the argument assumes what it is trying to prove.
Fallacy of Being Funny
This fallacy occurs when someone uses humor to manipulate someone into believing a claim
without providing an argument in favor of the claim. In other words, humor replaces evidence.
Now this doesn’t mean humor can’t be used to raise awareness of an issue, but it does mean that
humor doesn’t establish any position on an issue is true or false.
Here’s an example:
They’re talking about banning cigarette smoking now in any place that’s used by ten or
more people in a week, which, I guess, means that Madonna can’t even smoke in bed. –
Bill Maher, found at https://www.lifedaily.com/15-cynical-bill-maher-quotes-aboutreligion-and-politics/. Article by Addam Corre.
Here Maher uses humor to mock the idea that people shouldn’t be allowed to smoke in crowded
places. Of course, it doesn’t demonstrate that the ban is a bad idea. That depends on the ethical
and medical considerations.
Appeal to the People (AKA: Bandwagon Argument or Ad Populum)
This fallacy occurs when one uses the mere fact that something is widely believed or accepted as
evidence for a claim. But beliefs can be false. Thus, the mere fact that something is widely
believed doesn’t show it is true.
Throughout most of human history slavery was endorsed, from the Ancient Greeks to early
America. But the mere fact that it was widely accepted didn’t show slavery was acceptable. It’s
still wrong to enslave people since it takes their freedom away.
Appeal to Pity
Someone appeals to pity when they try to sway someone to a position merely on the grounds that
we should feel sorry for someone. A lawyer may try to reduce the sentence of their client on the
grounds that he had a bad childhood and was abused. However, someone is guilty if they
committed the crime and knew what they were doing at the time of the crime. Their past is no
excuse. It’s unfortunate some parents are awful, but that doesn’t absolve people of their wrongful
actions.
Non-Sequitur
This fallacy occurs when the conclusion of an argument isn’t logically supported by the premises
(i.e., the argument is invalid and weak). One thing to keep in mind is that this fallacy only
applies when other fallacies do not: it’s a catch-all fallacy. Most arguments which commit the
other fallacies are also non-sequiturs. However, fallacious arguments are only called nonsequiturs if the other fallacies do not apply.
Here’s an example where a senator is trying to pass a bill to get school children laptops: - Children are our most important investment.
- Schools help ensure children are prepared for adulthood.
- No one opposes children, (1) or (2).
So, we should pass the bill.
With your guard down, this might appear to be logical. However, the conclusion isn’t supported
at all. What we need is evidence that passing the bill will improve learning. The mere fact that
children and schools are important doesn’t show that.
Genetic Fallacy
“Genetic” here means origins. If one uses the origins of a view—what initially caused the belief
or view to be—for or against a view, they have committed the genetic fallacy. Maybe people
have silly reasons to believe something. However, that doesn’t show their beliefs are false
because there may be good evidence otherwise. What one needs to do is evaluate all evidence for
or against a view.
For example, some people claim religious people only believe in God to make life more
tolerable. I doubt that’s the only reason, but let’s say it’s true. It doesn’t show God doesn’t exist.
We need to evaluate the evidence for or against God.
Something similar happens with atheism. Some people argue atheists just hate religion and that’s
why they deny God’s existence. I doubt that too, but it wouldn’t show God exists even if true.
Again, the arguments about God’s existence need to be evaluated.
Appeal to Ignorance
This fallacy occurs when one argues that because something hasn’t been shown false that it must
be true. Or that because something hasn’t been shown true that it is false.
Here’s a couple examples: - No one has shown that astrology is false, so it’s reasonable to believe in it.
- No one has shown conclusively that ghosts don’t exist, so they must exist.
- No one has shown God exists; therefore, God doesn’t exist.
For (1), just because something hasn’t been shown false doesn’t mean it’s reasonable to believe
in it. There may be no good evidence in favor of it either. Similarly, for (2). For (3), while it’s
true no one has proved God exists that doesn’t mean God doesn’t. God may just prefer to remain
hidden or not care about humans at all, for example.
Straw Man
The straw man fallacy occurs when someone misrepresents someone’s argument or view, usually
to present it as weaker or sillier than it is. This fallacy is very common in politics.
Around the market crash of ’08, some people argued that regulations should be put in place to
prevent banks from taking on risky loans, which were part of the problem at the time. This view
was misrepresented as an endorsement of socialism.
Socialism is an economic system where the means of production are owned publicly, either run
by the government or, if there is no government, collectively by the people. In other words, no
private businesses or capital that produce products or services. Socialism is not the same thing as
a mere endorsement of regulations or laws. There can be private businesses and regulations.
Maybe the regulations would have been good or maybe not, but socialism was not a part of the
original argument.
A simpler example:
Appeal to Irrelevant Authority (AKA: Appeal to Authority)
This fallacy occurs when one appeals to someone’s expertise who is not an expert on the matter
at hand. It’s good to gather evidence from experts on a subject. For example, it’s smart to go to a
biologist for information on biology. Similarly, with a philosopher for philosophy, a truck driver
for trucking, a chemist for chemistry, etc.
The fallacy is committed when you get evidence or an opinion from someone who is not an
expert on the issue you are trying to address. For example, Tom Cruise is an actor. Appealing to
his opinion on psychology is a poor idea. You’d be appealing to an irrelevant authority. Your
medical doctor knows medicine. Their views on politics (e.g., who to elect) shouldn’t be trusted
anymore than a random person in a crowd.
False Cause
Someone who believes A causes B merely because A happened before B has committed the
fallacy of false cause. For example, Amy was fired after Bob got a raise, so clearly Bob is
influencing management in nefarious ways. Just because Bob got a raise doesn’t mean he caused
Amy to get fired.
A more sophisticated version of this fallacy occurs when someone argues that because A and B
are heavily correlated, one causes the other. For example, spending on science, space and
technology correlates with suicides by hanging, strangulation and suffocation. That doesn’t mean
spending is causing suicides. A lot of things happen all over the world all the time. Sometimes,
things occur simultaneously by coincidence. See: http://www.tylervigen.com/spuriouscorrelations.
Keep in mind, good causal arguments start with correlations. Correlation is necessary for
establishing causation but it’s not sufficient. Here’s an example to demonstrate that idea. Ice
cream sales may go up as it gets hotter, but we need more for a good argument. When we add in
the premise that humans cool down with cold food, we then can conclude that heat plays a role in
ice cream sales.
Slippery Slope
A slippery slope occurs when one argues that if we grant some claim, then we must grant others.
But no good reason is given for thinking this will occur. Think of it this way, the first step when
falling down a slope is to accept a claim, then when you accept another, you continue your way
down until you reach the bottom. Usually, when someone commits this fallacy, they are trying to
get someone to reject the initial claim by arguing that soon we’ll have to accept crazier and
crazier claims, even though they have no reason to believe we would have to accept the crazier
claims by merely accepting the initial one.
A common slippery slope argument I heard growing up was one arguing against gay marriage.
The argument was that if we allow gay marriage, then why not marriage to animals or children?
What’s stopping it?
This is not a good argument. A lot is stopping it. No one is going to endorse a bill permitting
children and animals to marry. And children and animals cannot agree to a marriage contract.
False Dilemma
A false dilemma occurs when one only considers a few options but there are more available. It
can also occur when one argues there are only a couple options but there are more.
I saw this occur in the early 00s around the time of the Iraq war. Many people, including TV
“personalities” and “talking heads”, committed this fallacy with the following argument:
You’re either for the war or you hate America. You’re against the war, so you hate
America.
Of course, there’s another option: you are against the war and you do not hate America.
Fallacy of Suppressed Evidence
This fallacy occurs when one ignores evidence against one’s own view. Rather than trying to
figure out the truth of the matter, one only looks at favorable evidence. This fallacy is like the
fallacy called cherry picking where one only gathers evidence in favor of one’s position.
A used car salesperson may ignore evidence that would not support her endorsement of a
vehicle. That’s suppressing evidence.
Equivocation
This fallacy occurs when one uses a key word in different ways (usually without realizing it).
Here’s a textbook example:
Only men have the right to vote. Women aren’t men. So, women don’t have the right to
vote.
Though less common today, the word ‘men’ was often used to refer to human beings in general.
So, in this argument, the meaning changes from human beings in the first statement to gendered
or sexed males in the second. But in that case, the conclusion doesn’t follow.
Notice further that if we use the word ‘men’ consistently, then we will have a false premise. If
‘men’ means human beings, then the second statement is false. If ‘men’ means male humans,
then the first premise is false.
Equivocations are often difficult to spot. They often occur in arguments on difficult topics. - Conclusion
Informal fallacies are common. But not all arguments that appear to be fallacies are. Be sure to
be charitable to others’ ideas whenever possible.
