Informal Fallacies

Complex Question Fallacy

(Also known as a loaded question, trick question, or fallacy of presupposition) This fallacy asks a question that has a presupposition built in, which implies something (which is often questionable) but protects the person asking the question from accusations of false claims or even slander. ex.: I heard a lot of noise in my back yard last night. So, did you climb the fence to get in, or pick the lock on the gate?

Equivocation

(Also known as doublespeak) This is a fallacy where one uses an ambiguous term or phrase in more than one sense, thus rendering the argument misleading. The ambiguity in this fallacy is lexical and not grammatical, meaning the term or phrase that is ambiguous has two distinct meanings. One can often see equivocation in jokes. ex.: A feather is light, and whatever is light cannot be dark; therefore, a feather cannot be dark.

False Dilemma

(Also known as false dichotomy, black-and-white fallacy) This fallacy arises when only two choices are offered in an argument or proposition, when in fact a greater number of possible choices could exist between the two extremes. False dilemmas typically contain 'either...or' in their structure. ex.: Either you help us kill the zombies, or you love them.

Fallacy of the Undistributed Middle

(Also known as undistributed middle term) This is a formal fallacy that occurs in a categorical syllogism when the middle term is not distributed into at least one premise. According to the rules of categorical syllogism, the middle term must be distributed at least once for it to be valid. ex.: Example of the form: All Xs are Ys; All Zs are Ys; therefore, All Xs are Zs. Example in words: All ghosts are spooky; all zombies are spooky; therefore, all ghosts are zombies.

Non-Sequitur Fallacy

(Latin: 'does not follow') A logical fallacy that is most often absurd, where the premises have no logical connection with or relevance to the conclusion. ex.: As your lawyer, I need you to answer this question: What do you think of my haircut?

Hasty Generalization

(also known as argument from small numbers, unrepresentative sample) This fallacy occurs in the realm of statistics. It happens when a conclusion or generalization is drawn about a population and it is based on a sample that is too small to properly represent it. ex.: My grandfather drank a bottle of whiskey and smoked three cigars a day, and he lived to be 95 years old. Therefore, daily smoking and drinking cannot be that bad for you.

Fallacy of Composition

(also known as exception fallacy) this is the fallacy of assuming that when a property applies to all members of a class, it must also apply to the class as a whole. ex.: Every player in the NHL is wealthy; therefore, the NHL must be a wealthy organization. The atoms that make up my body are all invisible. Therefore, my body is invisible!

Fallacy of Division

(also known as false division, or faulty division) this fallacy assumes that when a property applies to the class as a whole, it must also apply to every member of that class as well. ex.: This machine is very heavy. Therefore, all the parts of the machine will be very heavy too. It's safe to eat ordinary table salt—so it must also be safe to eat pure sodium and chloride, because that's what salt is made of.

fallacy

(n.) a false notion or belief; an error in thinking want your reasoning to be strong and cogent

Difference between Straw man and Red Herring

Straw man: involves deception Red Herring: involves distraction

Slippery Slope

This fallacy involves arguing that taking some particular action will inevitably or necessarily lead to other (usually bad) consequences, without providing enough reasons why the further consequences are inevitable. ex.: If we allow more English schools in Quebec, eventually we will have to allow more English speaking businesses. Then whole towns will become more and more English, and the French language will practically disappear.

Begging the Question

This is also sometimes called circular fallacy: It is the fallacy of attempting to prove something by assuming the very thing you are trying to prove. In its form, the conclusion occurs as one of the premises, or concerning a chain of arguments the final conclusion is a premise in an earlier argument. ex.:He's in jail. Innocent people don't go to jail, only guilty people do. So, clearly, he's guilty!

Faulty Analogy

This one occurs when someone uses an analogy to prove or disprove an argument or position, but this analogy is too dissimilar to be effective. ex.: Dogs are warm-blooded, nurse their young, and give birth to puppies. Humans are warm blooded and nurse their young. Therefore, humans give birth to puppies. During your years at college, you had almost no free time. Now you say you want to do a night course with a local artists' club. You'll end up with no free time again.

The Fallacy Fallacy

When someone assumes that the conclusion must be false because the argument leading to it is a fallacy, philosophers often call this the fallacy fallacy. An argument that is a fallacy is an unsound argument; but the conclusion of a fallacy might be true for some other reason. ex.: Eating Tide Pods is bad for you because my mom, my teacher, and my older brother said so (Appeal to Authority— but eating Tide Pods really is bad for you!)

Straw Man Fallacy

a straw man tends to happen when one person is criticizing or attacking another's position or argument. It occurs when she misrepresents or purposely distorts the position or argument of her opponent in order to weaken it, thus defeating it more easily. ex.:The members of Black Lives Matter say that they are fighting racism. But they are actually hypocrites, because they are implying that white lives don't matter.

Fallacy of Accident

also known as the fallacy of sweeping generalization. It is an attempt to apply a general rule to a situation with disregard for relevant exceptions to that rule. ex.: General rule: All birds can fly. Exceptions: Flightless birds like kiwi, penguin, emu, ostrich, and rhea.

Abusing the Man (Ad Hominem)

any attempt to disprove a proposition or argument by launching a personal attack on the author of it. A person's character, or any of her actions that are unrelated to the discussion, does not necessarily predict the truth or falsity of a proposition or argument. ex.: We shouldn't listen to those Antifa protesters. They are all just a rabble of troublemakers, and they only care about themselves.

Appeal to Popularity

attempts to use the popularity of a position or premise as evidence for its truthfulness. ex.: All the mothers in my child's daycare are giving quinoa to their kids, so it must be the best thing for them. The iPod is a great product. Ten million people bought one.

Appeal to Tradition

cites historical preferences and practives of a culture or even a particular person, as evidence for a proposition or argument being correct. ex.: We have turkey for Thanksgiving dinner and duck for Christmas dinner every year, because that is what my parents and grandparents always had.

False Cause

comes about when one argues that because X happened immediately after Y, that Y was the cause of X. In a sense, it is jumping to a conclusion based upon coincidence, rather than on sufficient testing, repeated occurrence, or evidence. ex.: The sun always rises a few minutes after the rooster crows. So, the rooster crowing causes the sun to rise.

Amphiboly

is a fallacy of ambiguity, where the ambiguity in question arises directly from the poor grammatical structure in a sentence. The fallacy occurs when a bad argument relies on the grammatical ambiguity to sound strong and logical. ex.: I took some pictures of the dogs at the park playing, but they were not good.

Red Herring

is committed when someone raises an irrelevant issue in the middle of an argument, derails the original discussion, and causes the argument to contain two totally different and unrelated issues. ex.: "Did you clean your room?" Answer: "Well I started, but it got too hot up there. You know, we really need to get the air conditioning fixed. And why haven't you taken me shopping for summer clothes yet?"

Naturalistic Fallacy

occurs when a person bases their argument or position on the notion that what is natural is better or what 'ought to be'. In other words, the foundation for the argument or position is a value judgment; the fallacy is committed when the argument shifts from a statement of fact to one of value. ex.: it is only natural to feel angry sometimes; therefore, there is nothing wrong with feeling angry.

Appeal to Novelty

opposite of appeal to tradition, claims the newness or modernity of something is presented as evidence of its truth and superiority. ex.: String theory is a new and rising research area in particle physics, and therefore it must be true.

Appeal to Authority

prove a conclusion by improper appeal to the opinion of an authority. ex.: My mom says if I eat watermelon seeds, a plant will grow in my belly and I'll turn green. Because my mom said it, it must be true.

Tu Quoque

this is the fallacy of asking 'But what about you? it is the rhetorical device that is often used by people who are accused of something. ex.: Speaker 1: This man running for office campaigned against same-sex marriage, but he was caught by the police in an airport bathroom with a male prostitute. I can't vote for him. Speaker 2: But what about your candidate's emails? She used a private email server for government business. She's just as bad!

Appeal to Ignorance

to argue for or against a proposition or position because there is a lack of evidence against or for it. ex.: There is intelligent life on Neptune, for sure. Science has not found any evidence that there isn't life there.

Appeal to Emotion

to make someone accept a proposition or argument by arousing and exploiting their emotions to subvert someone's rational thinking. ex.: The defendant should not be found guilty of this crime. Her life has been filled with endless abuse, a lack of love and respect, and so many hardships.

Appeal to Force

to make someone accept a proposition or argument by using some type of force of threat, possibly including the threat of violence. ex.: I believe the Baccus Players should perform "Antigone" this year, and if they perform anything else, I'll burn down the theatre.

Shifting the Burden of Proof

to make someone else take up this burden commit the fallacy of shifting the burden of proof (bring forth the evidence that some statement is true) away from themselves onto someone else. ex.: Aliens must exist. Until scientists study every planet in the universe and show me there aren't any aliens anywhere, I will continue to believe that they exist.