FLAWS Flashcards
(39 cards)
Irrelevant Evidence
When an author misuses information to such a degree that they fail to provide any information to support their conclusion or provide information that is irrelevant to their conclusion.
For example:
The sky is blue. Therefore, we should go eat at McDonalds.
Note:
This example is extreme, but the principle is that the conclusion does not follow at all from the support.
Internal Contradiction
Either the conclusion contradicts one of the premises or two of the premises contradict each other.
For example:
We should not do anything illegal. Driving over the speed limit, though against the law, is convenient and enables one to get to where he or she is going faster than would otherwise be possible. It carries some risks, but those risks are usually outweighed by the benefits. Therefore, we should drive over the speed limit.
Hasty Generalization
A conclusion that generalizes from an unrepresentative sample, usually from one or a few to “all” or “most.”
Unconnected Terms
The author illicitly assumes that the first time is equivalent to the second term, or that the first time implies the second term.
For example:
Working alone cannot lead to synergistic creations. Therefore, artists who eschew collaboration cannot create great works of art.
Note:
this is especially common when a new term is introduced in the conclusion. However, it can also be two terms in the premises that are not connected but must be connected if the conclusion is to follow.
Appeal to Ignorance
An argument in which the argument concludes that something doesn’t exist or isn’t true, on the basis that no evidence against it has been found.
For example:
We have yet to find any evidence of the existence of aliens on other planets. Therefore, aliens don’t exist.
Appeal to Ignorance - True
An argument in which the argument concludes that something does exist or is true, on the basis that no evidence against it has been found against it.
For example:
No one has been able to prove that aliens do not exist. Therefore, aliens do exist.
Weakening Disproves (Conclusion)
An argument in which the author weakens the argument for a given conclusion and then concludes that the conclusion for that argument is false.
For example:
Jack Smith claims that the Native Americans are descendants from an East Asian nomadic tribe that came over on a land bridge. However, the source he relied on for his history was later shown to be fabricated. Therefore, his claim is false.
Strengthening Proves (Conclusion)
An argument in which the author strengthens the argument for a given conclusion and then concludes that the conclusion for that argument is true.
For example:
Jack Smith claims that the Native Americans are descendants from an East Asian nomadic tribe that came over on a land bridge. Recently, archaeologists discovered a kind of boat in modern day Alaska that previously has only been discovered in East Asia. This shows that his claim was true.
Source
An author attacks the person or group of people making the argument (the argument’s source) to conclude that their conclusion/claim is false and should be dismissed.
Circular Reasoning
An argument in which the conclusion is identical with one of the premises.
For example:
Chocolate Green Tea Forest is the best Baskin Robins ice cream flavor, because it is better than all the rest.
Mistaken Reversal
“A –> B
B
Therefore, A.
An author concludes that the sufficient condition is true, because the necessary condition is true.”
For example:
All tables have four legs. This cat has four legs. Therefore, this cat is a table.
Mistaken Negation
“A –> B
/A
Therefore, /B.
An author concludes that the necessary condition is false, because the sufficient condition is false.”
For example:
All tables have four legs. This cat is not a table. Therefore, this cat does not have four legs.
Correlation = Causation
The author concludes that A causes B on the basis that A and B have been observed to be correlated.
For example:
99% of people who are involved in a car accident are wearing shoes at the time of the accident. This shows that wearing shoes increases the likelihood of being in a car accident.
Alternate Cause
The author argues A causes B, when there is an possible (usually obvious) alternative cause/explanation.
For example:
People who shop at Whole Foods tend to have fewer health problems and live longer than people who shop at Walmart. This shows that the food at Whole Foods promotes longevity.
Reversed Cause
The author argues A causes B, when it is just as likely that the causal pattern is reversed.
For example:
A study found that those who used social media the most were also the most likely to have depression and suicidal ideation. Therefore, social media is ruining the mental health of those who use it.
Post hoc ergo propter hoc
The author assumes that A causes B, just because B happened after A happened.
For example:
James drank a Fresca and then he had a heart attack. Therefore, drinking Fresca was the cause of his heart attack.
Sole Cause
The author assumes that A is the only that causes B, when it’s possible that other things could also cause the same effect.
For example:
Smoking cigarettes causes lung cancer. Therefore, if we can convince all members of society to quit smoking, we can prevent all lung cancer.
Straw Man
The author attacks a weaker version of the real argument to make it easier to refute.
For example:
“Center Left Politician: I think that it is reasonable to moderately increase taxes on the top income brackets to ensure that the poorest people in our country can have access to healthcare.
Angry Right Politician: So what you’re saying is that you don’t respect people’s right of private property, because you think that the government should be able to take as much of our money as it wants to give to the needy.”
Appeal to Authority
The author uses an authority as the sole support of the conclusion’s truth, usually an authority from an unrelated field (thus, illegitimate authority).
For example:
It has been proposed that we should mandate measles vaccination for all school children. However, the majority of NBA players have expressed strong opposition to this measure. Therefore, it should not be adopted.
Appeal to Popular Opinion
A conclusion is claimed to be true because many people believe it.
For example:
Most people think fast food is healthy. Therefore, it can’t be true that eating fast food is unhealthy.
Appeal to Emotion
The author appeals to emotion (usually pity, like the etymology of the fallacy – ad misericordiam, appeal to pity) to justify the conclusion without any other support.
For example:
Attorney: Your honor, though it may appear that my client is guilty of the charges brought against her today, she should not be convicted. After all, she was brought up by a meth addicted mother in a single-wide trailer with flat tires, in which she was beaten every day with a tire iron and told she was fat and worthless.
Survey - Biased Sample
An author draws a conclusion about a given population from an unrepresentative subset of the population.
For example:
Sociologist: Desiring to ascertain rates of youth video game playing in Springfield, we stationed ourselves at the local internet cafe for a full day and asked all of the recipients that visited the cafe how many hours per day they played on average. To our surprise, the average given was 14 hours per day. Based on this, we concluded that there is a serious video game addiction problem among the youth in Springfield.
Survey - Faulty Questions
The survey uses bad questions (whether deliberately or not) that bias the answers. They then draw their conclusion from these biased answers.
For example:
Sociologists set up a table at the Occupy Wallstreet Movement in New York City. They put up a sign, asking for volunteers to answer a survey. One of the questions asked, “Which economic system do you prefer, capitalism or slavery?” To their surprise, every person answered “capitalism.” This shows that, contrary to expectation, the Occupiers are all capitalists.
Survey - Lying Answers
The survey asks about something and then concludes something based upon the answers, but without considering that the people responding could be lying.
For example:
North Koreans were polled on the street by the government news organization as to who the greatest world leader in history was. They all answered Kim Il-Sung. This shows that North Koreans think that Kim Il-Sung is the greatest leader in history.
