Accent
The accent fallacy is a fallacy of ambiguity due to the
different ways a word is emphasized or accented.
Example:
A member of Congress is asked by a reporter if she is in favor of the President's new missile defense system, and she responds, "I'm in favor of a missile defense system that effectively defends America."
With an emphasis on the word "favor", this remark is likely to favor the President's missile defense system. With an emphasis, instead, on the words "effectively defends", this remark is likely to be against the President's missile defense system. Aristotle's fallacy of accent allowed only a shift in which syllable is accented within a word.
Ad Baculum
See Scare Tactic and Appeal to Emotions (Fear).
Ad Consequentiam
Ad Hominem
You commit this fallacy if you make an irrelevant attack on
the arguer and suggest that this attack undermines the argument itself. It is a
form of the
Genetic Fallacy.
Example:
What she says about Johannes Kepler's astronomy of the 1600's must be just so much garbage. Do you realize she's only fourteen years old?
This attack may undermine the arguer's credibility as a scientific authority, but it does not undermine her reasoning. That reasoning should stand or fall on the scientific evidence, not on the arguer's age or anything else about her personally.
If the fallacious reasoner points out irrelevant circumstances that the reasoner is in, the fallacy is a circumstantial ad hominem. Tu Quoque and Two Wrongs Make a Right are other types of the ad hominem fallacy.
The major difficulty with labeling a piece of reasoning as an ad hominem fallacy is deciding whether the personal attack is relevant. For example, attacks on a person for their actually immoral sexual conduct are irrelevant to the quality of their mathematical reasoning, but they are relevant to arguments promoting the person for a leadership position in the church. Unfortunately, many attacks are not so easy to classify, such as an attack pointing out that the candidate for church leadership, while in the tenth grade, intentionally tripped a fellow student and broke his collar bone.
Ad Ignorantiam
See Appeal to Ignorance.
Ad Misericordiam
See Appeal to Emotions.
Ad Novitatem
See Bandwagon.
Ad Numerum
See Appeal to the People.
Ad Populum
See Appeal to the People.
Ad Verecundiam
See Appeal to Authority.
Affirming the Consequent
If you have enough evidence to affirm the consequent of a
conditional and then suppose that as a result you have sufficient reason for
affirming the antecedent, you commit the fallacy of affirming the consequent.
This formal fallacy is often mistaken for modus ponens, which is a
valid form of reasoning also using a conditional. A conditional is an
if-then statement; the if-part is the antecedent, and the then-part is the
consequent. The following argument affirms the consequent that she does speaks
Portuguese.
Example:
If she's Brazilian, then she speaks Portuguese. Hey, she does speak Portuguese. So, she is Brazilian.
If the arguer believes or suggests that the premises definitely establish that she is Brazilian, then the arguer is committing the fallacy. See the non sequitur fallacy for more discussion of this point.
Anecdotal Evidence
If you discount evidence arrived at by systematic search or
by testing in favor of a few firsthand stories, you are committing the fallacy
of overemphasizing anecdotal evidence.
Example:
Yeah, I've read the health warnings on those cigarette packs and I know about all that health research, but my brother smokes, and he says he's never been sick a day in his life, so I know smoking can't really hurt you.
Anthropomorphism
This is the error of projecting uniquely human qualities
onto something that isn't human. Usually this occurs with projecting the human
qualities onto animals, but when it is done to nonliving things, as in calling
the storm cruel, the
pathetic fallacy is created. There is also, but less commonly, called the
Disney Fallacy or the Walt Disney Fallacy.
Example:
My dog is wagging his tail and running around me. Therefore, he knows that I love him.
The fallacy would be averted if the speaker had said "My dog is wagging his tail and running around me. Therefore, he is happy to see me." Animals are likely to have some human emotions, but not the ability to ascribe knowledge to other beings. Your dog knows where it buried its bone, but not that you also know where the bone is.
Appeal to Authority
You appeal to authority if you back up your reasoning by
saying that it is supported by what some authority says on the subject. Most
reasoning of this kind is not fallacious. However, it is fallacious
whenever the authority appealed to is not really an authority in this subject,
when the authority cannot be trusted to tell the truth, when authorities
disagree on this subject (except for the occasional lone wolf), when the
reasoner misquotes the authority, and so forth. Although spotting a fallacious
appeal to authority often requires some background knowledge about the subject
or the authority, in brief it can be said that it is fallacious to accept the
word of a supposed authority when we should be suspicious.
Example:
You can believe the moon is covered with dust because the president of our neighborhood association said so, and he should know.
This is a fallacious appeal to authority because, although
the president is an authority on many neighborhood matters, he is no authority
on the composition of the moon. It would be better to appeal to some astronomer
or geologist. If you place too much trust in expert opinion and overlook any
possibility that experts talking in their own field of expertise make mistakes,
too, then you also commit the fallacy of appeal to authority.
Example:
Of course she's guilty of the crime. The police arrested her, didn't they? And they're experts when it comes to crime.
Appeal to Consequence
Arguing that a belief is false because it implies something
you'd rather not believe. Also called Argumentum Ad Consequentiam.
Example:
That can't be Senator Smith there in the videotape going into her apartment. If it were, he'd be a liar about not knowing her. He's not the kind of man who would lie. He's a member of my congregation.
Smith may or may not be the person in that videotape, but this kind of arguing should not convince us that it's someone else in the videotape.
Appeal to Emotions
You commit the fallacy of appeal to emotions when someone's appeal to you to accept their claim is accepted merely because the appeal arouses your feelings of anger, fear, grief, love, outrage, pity, pride, sexuality, sympathy, relief, and so forth. Example of appeal to relief from grief:
[The speaker knows he is talking to an aggrieved person whose house is worth much more than $100,000.] You had a great job and didn't deserve to lose it. I wish I could help somehow. I do have one idea. Now your family needs financial security even more. You need cash. I can help you. Here is a check for $100,000. Just sign this standard sales agreement, and we can skip the realtors and all the headaches they would create at this critical time in your life.
There is nothing wrong with using emotions when you argue, but it's a mistake to use emotions as the key premises or as tools to downplay relevant information. Regarding the fallacy of appeal to pity, it is proper to pity people who have had misfortunes, but if as the person's history instructor you accept Max's claim that he earned an A on the history quiz because he broke his wrist while playing in your college's last basketball game, then you've committed the fallacy of appeal to pity. However, if you realize he didn't earn the A, but nevertheless you still give him an A, then you have not committed the fallacy, but you may have acted improperly.
Appeal to Ignorance
The fallacy of appeal to ignorance comes in two forms: (1)
Not knowing that a certain statement is true is taken to be a proof that it is
false. (2) Not knowing that a statement is false is taken to be a proof that it
is true. The fallacy occurs in cases where absence of evidence is not good
enough evidence of absence. The fallacy uses an unjustified attempt to shift the
burden of proof. The fallacy is also called "Argument from Ignorance."
Example:
Nobody has ever proved to me there's a God, so I know there is no God.
This kind of reasoning is generally fallacious. It would be proper reasoning only if the proof attempts were quite thorough, and it were the case that if God did exist, then there would be a discoverable proof of this.
Avoiding the Question
The fallacy of avoiding the question is a type of fallacy
of avoiding the issue that occurs when the issue is how to answer some question.
The fallacy is committed when someone's answer doesn't really respond to the
question asked.
Example:
Question: Would the Oakland Athletics be in first place if they were to win tomorrow's game?
Answer: What makes you think they'll ever win tomorrow's game?
Begging the Question
A form of
circular reasoning in which a conclusion is derived from premises that
presuppose the conclusion. Normally, the point of good reasoning is to start out
at one place and end up somewhere new, namely having reached the goal of
increasing the degree of reasonable belief in the conclusion. The point is to
make progress, but in cases of begging the question there is no progress.
Example:
"Women have rights," said the Bullfighters Association president. "But women shouldn't fight bulls because a bullfighter is and should be a man."
The president is saying basically that women shouldn't fight bulls because women shouldn't fight bulls. This reasoning isn't making an progress toward determining whether women should fight bulls.
Insofar as the conclusion of a deductively valid argument is "contained" in the premises from which it is deduced, this containing might seem to be a case of presupposing, and thus any deductively valid argument might seem to be begging the question. It is still an open question among logicians as to why some deductively valid arguments are considered to be begging the question and others are not. Some logicians suggest that, in informal reasoning with a deductively valid argument, if the conclusion is psychologically new insofar as the premises are concerned, then the argument isn't an example of the fallacy. Other logicians suggest that we need to look instead to surrounding circumstances, not to the psychology of the reasoner, in order to assess the quality of the argument. For example, we need to look to the reasons that the reasoner used to accept the premises. Was the premise justified on the basis of accepting the conclusion? A third group of logicians say that, in deciding whether the fallacy is committed, we need more. We must determine whether any premise that is key to deducing the conclusion is adopted rather blindly or instead is a reasonable assumption made by someone accepting their burden of proof. The premise would here be termed reasonable if the arguer could defend it independently of accepting the conclusion that is at issue.
Complex Question
You commit this fallacy when you frame a question so that
some controversial presupposition is made by the wording of the question.
Example:
[Reporter's question] Mr. President: Are you going to continue your policy of wasting taxpayer's money on missile defense?
The question unfairly presumes the controversial claim that the policy really is a waste of money. The fallacy of complex question is a form of begging the question.
Composition
The composition fallacy occurs when someone mistakenly
assumes that a characteristic of some or all the individuals in a group is also
a characteristic of the group itself, the group "composed" of those members. It
is the converse of the
division fallacy.
Example:
Each human cell is very lightweight, so a human being composed of cells is also very lightweight.
Cum Hoc, Ergo Propter Hoc
Latin for "with this, therefore because of this." This is a
false cause fallacy that doesn't depend on time order (as does the post hoc
fallacy), but on any other chance correlation of the supposed cause being in the
presence of the supposed effect.
Example:
Gypsies live near our low-yield cornfields. So, gypsies are causing the low yield.
Definist
The definist fallacy occurs when someone unfairly defines a
term so that a controversial position is made easier to defend. Same as the
Persuasive Definition.
Example:
During a controversy about the truth or falsity of atheism, the fallacious reasoner says, "Let's define 'atheist' as someone who doesn't yet realize that God exists."
Denying the Antecedent
You are committing a fallacy if you deny the antecedent of
a conditional and then suppose that doing so is a sufficient reason for denying
the consequent. This formal fallacy is often mistaken for modus tollens, a valid
form of argument using the conditional. A conditional is an if-then statement;
the if-part is the antecedent, and the then-part is the consequent.
Example:
If she were Brazilian, then she would know that Brazil's official language is Portuguese. She isn't Brazilian; she's from London. So, she surely doesn't know this about Brazil's language.
Digression
See Avoiding the Issue.
Equivocation
Equivocation is the illegitimate switching of the meaning
of a term during the reasoning.
Example:
Brad is a nobody, but since nobody is perfect, Brad must be perfect, too.
The term "nobody" changes its meaning without warning in the passage. So does the term "political jokes" in this joke: I don't approve of political jokes. I've seen too many of them get elected.
Etymological
The etymological fallacy occurs whenever someone falsely
assumes that the meaning of a word can be discovered from its etymology or
origins.
Example:
The word "vise" comes from the Latin "that which winds", so it means anything that winds. Since a hurricane winds around its own eye, it is a vise.
False Analogy
When reasoning by analogy, the fallacy occurs when the
analogy is irrelevant or very weak or when there is a more relevant disanalogy.
See also
Faulty Comparison.
Example:
The book Investing for Dummies really helped me understand my finances better. The book Chess for Dummies was written by the same author, was published by the same press, and costs about the same amount. So, this chess book would probably help me understand my finances.
False Cause
Improperly concluding that one thing is a cause of another.
The Fallacy of Non Causa Pro Causa is another name for this fallacy. Its four
principal kinds are the
Post Hoc Fallacy, the Fallacy of
Cum Hoc, Ergo Propter Hoc, the
Regression Fallacy, and the Fallacy of
Reversing Causation.
Example:
My psychic adviser says to expect bad things when Mars is aligned with Jupiter. Tomorrow Mars will be aligned with Jupiter. So, if a dog were to bite me tomorrow, it would be because of the alignment of Mars with Jupiter.
False Dichotomy
See False Dilemma or Black-or-White.
False Dilemma
A reasoner who unfairly presents too few choices and then
implies that a choice must be made among this short menu of choices commits the
false dilemma fallacy, as does the person who accepts this faulty reasoning.
Example:
I want to go to Scotland from London. I overheard McTaggart say there are two roads to Scotland from London: the high road and the low road. I expect the high road is dangerous because it's through the hills. But it's raining, so both roads are probably slippery. I don't like either choice, but I guess I should take the low road.
This would be fine reasoning is you were limited to only two roads, but you've falsely gotten yourself into a dilemma with such reasoning. There are many other ways to get to Scotland. Don't limit yourself to these two choices. You can take other roads, or go by boat or train or airplane. Think of the unpleasant choice as a charging bull. By demanding other choices beyond those on the unfairly limited menu, you thereby "go between the horns" of the dilemma, and are not gored. For another example of the fallacy, see Black-or-White.
Far-Fetched Hypothesis
This is the fallacy of offering a bizarre (far-fetched)
hypothesis as the correct explanation without first ruling out more mundane
explanations.
Example:
Look at that mutilated cow in the field, and see that flattened grass. Aliens must have landed in a flying saucer and savaged the cow to learn more about the beings on our planet.
Faulty Comparison
If you try to make a point about something by comparison,
and if you do so by comparing it with the wrong thing, you commit the fallacy of
faulty comparison or the fallacy of
questionable analogy.
Example:
We gave half the members of the hiking club Durell hiking boots and the other half good-quality tennis shoes. After three months of hiking, you can see for yourself that Durell lasted longer. You, too, should use Durell when you need hiking boots.
Shouldn't Durell hiking boots be compared with other hiking boots, not with tennis shoes?
Formal
Formal fallacies are all the cases or kinds of reasoning
that fail to be deductively valid. Formal fallacies are also called logical
fallacies or
invalidities.
Example:
Some cats are tigers. Some tigers are animals. So, some cats are animals.
This might at first seem to be a good argument, but actually it is fallacious because it has the same logical form as the following more obviously invalid argument:
Some women are Americans. Some Americans are men. So, some women are men.
Nearly all the infinity of types of invalid inferences have no specific fallacy names.
Gambler's
This fallacy occurs when the gambler falsely assumes that
the history of outcomes will affect future outcomes.
Example:
I know this is a fair coin, but it has come up heads five times in a row now, so tails is due on the next toss.
The fallacious move was to conclude that the probability of the next toss coming up tails must be more than a half. The assumption that it's a fair coin is important because, if the coin comes up heads five times in a row, one would otherwise become suspicious that it's not a fair coin and therefore properly conclude that the probably is high that heads is more likely on the next toss.
Genetic
A critic commits the genetic fallacy if the critic attempts
to discredit or support a claim or an argument because of its origin (genesis)
when such an appeal to origins is irrelevant.
Example:
Whatever your reasons are for buying that DVD they've got to be ridiculous. You said yourself that you got the idea for buying it from last night's fortune cookie. Cookies can't think!
Fortune cookies are not reliable sources of information about what DVD to buy, but the reasons the person is willing to give are likely to be quite relevant and should be listened to. The speaker is committing the genetic fallacy by paying too much attention to the genesis of the idea rather than to the reasons offered for it. An ad hominem fallacy is one kind of genetic fallacy, but the genetic fallacy in our passage isn't an ad hominem.
If I learn that your plan for building the shopping center next to the Johnson estate originated with Johnson himself, who is likely to profit from the deal, then my pointing out to the planning commission the origin of the deal would be relevant in their assessing your plan. Because not all appeals to origins are irrelevant, it sometimes can be difficult to decide if the fallacy has been committed. For example, if Sigmund Freud shows that the genesis of a person's belief in God is their desire for a strong father figure, then does it follow that their belief in God is misplaced, or does this reasoning commit the genetic fallacy?
Hedging
You are hedging if you refine your claim simply to avoid
counterevidence and then act as if your revised claim is the same as the
original.
Example:
Samantha: David is a totally selfish person.
Yvonne: I thought we was a boy scout leader. Don’t you have to give a lot of
your time for that?
Samantha: Well, David’s totally selfish about what he gives money to. He won’t
spend a dime on anyone else.
Yvonne: I saw him bidding on things at the high school auction fundraiser.
Samantha: Well, except for that he’s totally selfish about money.
You don’t commit the fallacy if you explicitly accept the counterevidence, admit that your original claim is incorrect, and then revise it so that it avoids that counterevidence.
Hooded Man
This is an error in reasoning due to confusing the knowing
of a thing with the knowing of it under all its various names or descriptions.
Example:
You claim to know Socrates, but you must be lying. You admitted you didn't know the hooded man over there in the corner, but the hooded man is Socrates.
Ignoratio Elenchi
Irrelevant Conclusion
If an arguer argues for a certain conclusion while falsely
believing or suggesting that a different conclusion is established, one for
which the first conclusion is irrelevant, then the arguer commits the fallacy of
irrelevant conclusion.
Example:
In court, Thompson testifies that the defendant is a honorable person, who wouldn't harm a flea. The defense attorney rises to say that Thompson's testimony shows his client was not near the murder scene.
The testimony of Thompson may be relevant to a request for leniency, but it is irrelevant to any claim about the defendant not being near the murder scene.
Irrelevant Reason
This fallacy is a kind of
non sequitur in which the premises are wholly irrelevant to drawing the
conclusion.
Example:
Lao Tze Beer is the top selling beer in Thailand. So, it will be the best beer for Canadians.
Line-Drawing
If we improperly reject a vague claim because it's not as
precise as we'd like, then we commit the line-drawing fallacy. Being vague is
not being hopelessly vague. Also called the Bald Man Fallacy, the Fallacy of the
Heap and the Sorites Fallacy.
Example:
Dwayne can never grow bald. Dwayne isn't bald now. Don't you agree that if he loses one hair, that won't make him go from not bald to bald? And if he loses one hair after that, then this one loss, too, won't make him go from not bald to bald. Therefore, no matter how much hair he loses, he can't become bald.
Loaded Language
Loaded language is emotive terminology that expresses value
judgments. When used in what appears to be an objective description, the
terminology unfortunately can cause the listener to adopt those values when in
fact no good reason has been given for doing so. Also called Prejudicial
Language.
Example:
[News broadcast] In today's top stories, Senator Smith carelessly cast the deciding vote today to pass both the budget bill and the trailer bill to fund yet another excessive watchdog committee over coastal development.
This broadcast is an editorial posing as a news report.
Non Sequitur
When a conclusion is supported only by extremely weak
reasons or by irrelevant reasons, the argument is fallacious and is said to be a
non sequitur. However, we usually apply the term only when we cannot think of
how to label the argument with a more specific fallacy name. Any deductively
invalid inference is a non sequitur if it also very weak when assessed by
inductive standards.
Example:
Nuclear disarmament is a risk, but everything in life involves a risk. Every time you drive in a car you are taking a risk. If you're willing to drive in a car, you should be willing to have disarmament.
The following is not an example: "If she committed the murder, then there'd be his blood stains on her hands. His blood stains are on her hands. So, she committed the murder." This deductively invalid argument commits the fallacy of affirming the consequent, but it isn't a non sequitur because it has significant inductive strength.
Persuasive Definition
Some people try to win their arguments by getting you to
accept their faulty definition. If you buy into their definition, they've
practically persuaded you already. Same as the
Definist Fallacy.
Poisoning the Well when presenting a definition would be an example of a
using persuasive definition.
Example:
Let's define a Democrat as a leftist who desires to overtax the corporations and abolish freedom in the economic sphere.
Poisoning the Well
Poisoning the well is a preemptive attack on a person in
order to discredit their testimony or argument in advance of their giving it. A
person who thereby becomes unreceptive to the testimony reasons fallaciously and
has become a victim of the poisoner. This is a kind of
ad hominem.
Example:
[Prosecuting attorney in court] When is the defense attorney planning to call that twice-convicted child molester, David Barnington, to the stand? OK, I'll rephrase that. When is the defense attorney planning to call David Barnington to the stand?
Post Hoc
Suppose we notice that an event of kind A is followed in
time by an event of kind B, and then hastily leap to the conclusion that A
caused B. If so, we commit the post hoc fallacy. Correlations are often good
evidence of causal connection, so the fallacy occurs only when the leap to the
causal conclusion is done "hastily." The Latin term for the fallacy is post hoc,
ergo propter hoc ("After this, therefore because of this"). It is a kind of
false cause fallacy.
Example:
I ate in that Ethiopian restaurant three days ago and now I've just gotten food poisoning. The only other time I've eaten in an Ethiopian restaurant I also got food poisoning, but that time I got sick a week later. My eating in those kinds of restaurants is causing my food poisoning.
Your background knowledge should tell you this is unlikely because the effects of food poisoning are felt soon after the food is eaten. Before believing your illness was caused by eating in an Ethiopian restaurant, you'd need to rule out other possibilities, such as your illness being caused by what you ate a few hours before the onset of the illness.
Quoting out of Context
If you quote someone, but select the quotation so that
essential context is not available and therefore the person's views are
distorted, then you've quoted "out of context." Quoting out of context in an
argument creates a
straw man fallacy.
Example:
Smith: I've been reading about a peculiar game in this article about vegetarianism. When we play this game, we lean out from a fourth-story window and drop down strings containing "Free food" signs on the end in order to hook unsuspecting passers-by. It's really outrageous, isn't it? Yet isn't that precisely what sports fishermen do for entertainment from their fishing boats? The article says it's time we put an end to sport fishing.
Jones: Let me quote Smith for you. He says "We...hook unsuspecting passers-by." What sort of moral monster is this man Smith?
Jones's selective quotation is fallacious because it makes Smith appear to advocate this immoral activity when the context makes it clear that he doesn't.
Rationalization
We rationalize when we inauthentically offer reasons to
support our claim. We are rationalizing when we give someone a reason to justify
our action even though we know this reason is not really our own reason for our
action, usually because the offered reason will sound better to the audience
than our actual reason.
Example:
"I bought the matzo bread from Kroger's Supermarket because it is the cheapest brand and I wanted to save money," says Alex [who knows he bought the bread from Kroger's Supermarket only because his girlfriend works there].
Red Herring
A red herring is a smelly fish that would distract even a
bloodhound. It is also a digression that leads the reasoner off the track of
considering only relevant information.
Example:
Will the new tax in Senate Bill 47 unfairly hurt business? One of the provisions of the bill is that the tax is higher for large employers (fifty or more employees) as opposed to small employers (six to forty-nine employees). To decide on the fairness of the bill, we must first determine whether employees who work for large employers have better working conditions than employees who work for small employers.
Bringing up the issue of working conditions is the red herring.
Reversing Causation
Drawing an improper conclusion about causation due to a
causal assumption that reverses cause and effect. A kind of
false cause fallacy.
Example:
All the corporate officers of Miami Electronics and Power have big boats. If you're ever going to become an officer of MEP, you'd better get a bigger boat.
The false assumption here is that having a big boat helps cause you to be an officer in MEP, whereas the reverse is true. Being an officer causes you to have the high income that enables you to purchase a big boat.
Scapegoating
If you unfairly blame an unpopular person or group of
people for a problem, then you are scapegoating. This is a kind of fallacy of
appeal to emotions.
Example:
Augurs were official diviners of ancient Rome. During the pre-Christian period, when Christians were unpopular, an augur would make a prediction for the emperor about, say, whether a military attack would have a successful outcome. If the prediction failed to come true, the augur would not admit failure but instead would blame nearby Christians for their evil influence on his divining powers. The elimination of these Christians, the augur would claim, could restore his divining powers and help the emperor. By using this reasoning tactic, the augur was scapegoating the Christians.
Sharpshooter's
The sharpshooter's fallacy gets its name from someone
shooting a rifle at the side of the barn and then going over and drawing a
target and bulls eye concentrically around the bullet hole. The fallacy is
caused by overemphasizing random results or making selective use of coincidence.
See the Fallacy of
Selective Attention.
Example:
Psychic Sarah makes twenty-six predictions about what will
happen next year. When one, but only one, of the predictions comes true, she
says, "Aha! I can see into the future."
Slanting
This error occurs when the issue is not treated fairly because of misrepresenting the evidence by, say, suppressing part of it, or misconstruing some of it, or simply lying. See the following fallacies: Lying, Misrepresentation, Questionable Premise, Quoting out of Context, Straw Man, Suppressed Evidence.
Slippery Slope
Suppose someone claims that a first step (in a chain of
causes and effects, or a chain of reasoning) will probably lead to a second step
that in turn will probably lead to another step and so on until a final step
ends in trouble. If the likelihood of the trouble occurring is exaggerated, the
slippery slope fallacy is committed.
Example:
Mom: Those look like bags under your eyes. Are you getting enough sleep?
Jeff: I had a test and stayed up late studying.
Mom: You didn't take any drugs, did you?
Jeff: Just caffeine in my coffee, like I always do.
Mom: Jeff! You know what happens when people take drugs! Pretty soon the caffeine won't be strong enough. Then you will take something stronger, maybe someone's diet pill. Then, something even stronger. Eventually, you will be doing cocaine. Then you will be a crack addict! So, don't drink that coffee.
The form of a slippery slope fallacy looks like this:
A leads to B.
B leads to C.
C leads to D.
...
Z leads to HELL.
We don't want to go to HELL.
So, don't take that first step A.
Think of the sequence A, B, C, D, ..., Z as a sequence of closely stacked dominoes. The key claim in the fallacy is that pushing over the first one will start a chain reaction of falling dominoes, each one triggering the next. But the analyst asks how likely is it really that pushing the first will lead to the fall of the last? For example, if A leads to B with a probability of 80 percent, and B leads to C with a probability of 80 percent, and C leads to D with a probability of 80 percent, is it likely that A will eventually lead to D? No, not at all; there is about a 50- 50 chance. The proper analysis of a slippery slope argument depends on sensitivity to such probabilistic calculations. Regarding terminology, if the chain of reasoning A, B, C, D, ..., Z is about causes, then the fallacy is called the Domino Fallacy.
Straw Man
You commit the straw man fallacy whenever you attribute an
easily refuted position to your opponent, one that the opponent wouldn't
endorse, and then proceed to attack the easily refuted position believing you
have undermined the opponent's actual position. If the misrepresentation is on
purpose, then the straw man fallacy is caused by lying.
Example (a debate before the city council):
Opponent: Because of the killing and suffering of Indians that followed Columbus's discovery of America, the City of Berkeley should declare that Columbus Day will no longer be observed in our city.
Speaker: This is ridiculous, fellow members of the city council. It's not true that everybody who ever came to America from another country somehow oppressed the Indians. I say we should continue to observe Columbus Day, and vote down this resolution that will make the City of Berkeley the laughing stock of the nation.
The speaker has twisted what his opponent said; the opponent never said, nor even indirectly suggested, that everybody who ever came to America from another country somehow oppressed the Indians.
Style Over Substance
Unfortunately the style with which an argument is presented
is sometimes taken as adding to the substance or strength of the argument.
Example:
You've just been told by the salesperson that the new Maytag is an excellent washing machine because it has a double washing cycle. If you were to notice that the salesperson smiled at you and was well dressed, this wouldn't add to the quality of the original argument, but unfortunately it does for those who are influenced by style over substance, as most of us are.
Subjectivist
The subjectivist fallacy occurs when it is mistakenly
supposed that a good reason to reject a claim is that truth on the matter is
relative to the person or group.
Example:
Justine has just given Jake her reasons for believing that the Devil is an imaginary evil person. Jake, not wanting to accept her conclusion, responds with, "That's perhaps true for you, but it's not true for me."
Unfalsifiability
This error in explanation occurs when the explanation
contains a claim that is not falsifiable, because there is no way to check on
the claim. That is, there would be no way to show the claim to be false if it
were false.
Example:
He lied because he's possessed by demons.
This could be the correct explanation of his lying, but there's no way to check on whether it's correct. You can check whether he's twitching and moaning, but this won't be evidence about whether a supernatural force is controlling his body. The claim that he's possessed can't be verified if it's true, and it can't be falsified if it's false. So, the claim is too odd to be relied upon for an explanation of his lying. Relying on the claim is an instance of fallacious reasoning.