LSAT Flaws

How to answer every kind of flaw question

What is Bad Conditional Reasoning

• Occurs when the author reads the conditionals supplied in the premises incorrectly

• The author reads the conditional chain wrong

Example of Bad Conditional Reasoning

If you ride a wild horse, you are an adventurous sort. All adventurous sorts desire the thrill of the new. Therefore, if you desire the thrill of the new, you must have ridden a wild horse.

Loophole of Bad Conditional Reasoning

What if we actually have to follow the rules of conditioning

ex. wild horse → adventurous sort → thrill of new

What is the flaw of this example of Bad Conditional Reasoning:

Unplugging a peripheral component such as a ‘mouse’ from a personal computer renders all of the software programs that require that component unusable on that computer. On Fred’s personal computer, a software program that requires a mouse has become unusable. So it must be that the mouse for Fred’s computer became unplugged.

Conclusion reads the conditional chain backwards without negating it

There may be many reasons it may not be working, not just that it is unplugged.

What is Bad Causal Reasoning

When two things are correlated and one assume that one is causing the other

Loophole for Bad Casual Reasoning

What if the Omitted Options is the Case?

What are the Omitted Options

No Relationship, Backwards Causation, New Factor Causing One or Both

Example of Bad Causal Reasoning

Natalie Portman’s lack of chemistry with Hayden Christensen and her outlandish costumes made the Star Wars prequels borderline unwatchable. Therefore, Natalie Portman caused the temporary downfall of the franchise.

What is the flaw in this example of Bad Causal Reasoning:

Chronic fatigue syndrome, a condition that afflicts thousands of people, is invariably associated with lower than normal concentrations of magnesium in the blood. Further, malabsorption of magnesium from the digestive tract to the blood is also often associated with some types of fatigue. These facts in themselves demonstrate that treatments that raise the concentration of magnesium in the blood would provide an effective cure for the fatigue involved in the syndrome.

Just because magnesium and fatigue are correlated, does not mean that low magnesium causes fatigue. Therefore, improving magnesium would not improve fatigue. Out of the omitted options, a new factor could be causing fatigue and magnesium or just one of them.

What is Whole-to-Part & Part-to-Whole

Assuming what is true of the whole of a property, is also true of a part of the property and vice versa.

Example of Whole-to-Part & Part-to-Whole

A Starbucks location has a sale, so every Starbucks under the corporation has the same sale

Loophole of Whole-to-Part & Part-to-Whole

What if whole’s don’t necessarily equal parts

What is the flaw of the Whole-to-Part & Part-to-Whole Example:

Each of the elements of Girelli’s recently completed design for a university library is copied from a different one of several historic libraries. the design includes various features from Classical Greek, Islamic, Mogul and Romanesque structures. Since no one element in the design is original, it follows that the design of the library cannot be considered original.

Just because the parts of the structure’s design were not original, does not mean the structure as a whole is not original. What if these parts has never previously been combined before.

What is Overgeneralization

Occurs when you have premises about something specific, and make a general conclusion from them

Loophole for Overgeneralization

What if we can’t generalize from this one thing to a bunch of other things

Example of Overgeneralization

Lina was quite clever in her paper on shark anatomy. So Lina is a clever person.

What is the flaw in this example of overgeneralization:

Those economists who claims that consumer price increases have averaged less than 3% over the last year are mistaken. They clearly have not shopped anywhere recently. Gasoline is up 10% over the last year; my auto insurance, 12%; newspapers, 15%; propane 13%; bread 50%

You can’t take a few examples and conclude that the economists are lying or wrong.

What Are Survey Problems

Surveys may seem reasonable but they are often done incompetently, with many silent things wrong with them

Loophole For Survey Problems

What if the sample was biased, the questions were biased, there are other contradictory surveys, people lied on the survey, or the sample size is too small

Explain the loopholes for survey problems

• Biased Sample

  • Unrepresentative group

• Biased Questions

  • Crafting questions to get certain answers

• Survey Liars

  • Question gives respondents reasons to lie OR lie without incentive

  • The respondents are lying/inclined to lie

• Small Sample Size

  • Not enough respondents

• Other Contradictory Surveys

  • Survey results say something, when other evidence says the opposite, making us doubt the conclusion

What is the flaw in this example of survey problems:

A survey alumni of the class of 1960 at Aurora University yielded puzzling results. When asked to indicate their academic rank, half of the respondents reported that they were in the top quarter of the graduating class in 1960.

How could half of the students be in the top quarter of the class? People lied on the survey.

What are False Starts

Researchers always assume that the two groups are the same in all aspects except ones called out in the study

Despite the researchers assumptions, the two groups always have the possibility of being different

Example of False Starts

A researcher compares two groups: one exercises and one does not. You get results saying the groups that exercises is healthier.

It is easy to assume that the group is healthier because they exercise, but that is the trap, there could be many other reasons why.

Loophole for False Starts

What if the two groups were different in a key respect

What is the flaw in this example of false starts:

In a recent study, each member of two groups of people, Group A (composed of persons 65-75) and Group B (college students) was required to make a telephone call to a certain number at a specified time. That time when each call was initiated was recorded electronically. Group A proved far better at remembering to make a telephone call precisely at a specified time than did Group B. There were 14 lapses in Group B, but only 1 in Group A. Clearly, at least one type of memory does not suffer as a person ages.

Researchers assume that college students and old people are equal in all respects except their age. Ignored the fact that college students don’t have access to phones, and have more time commitments.

Possibility ≠ Certainty

It is fine to say someone has not proven their conclusion, and it is not necessarily true. It is not fine to assume that if someone has not proven their conclusion, the conclusion cannot be true.

Facts are not affected by the failure of an argument.

Loophole for Possibility ≠ Certainty

What if lack of evidence ≠ evidence of lacking (if it is not necessarily true, it does not mean it cannot be true)

What if proof of evidence ≠ evidence of proof (it could be true, it does not mean it must be true)

What is the flaw in this example of Possibility ≠ Certainty:

Despite the best efforts of astronomers, no one has yet succeeded in exchanging messages with intelligent life on other planets or in other solar systems. In fact, no one has even managed to prove that any kind of extraterrestrial life exists. Thus, there is clearly no intelligent life anywhere but on Earth.

Just because it hasn’t been proven that intelligent life exists, it does not mean it cannot exist.

What is an Implication

Opinions and facts do not play well together. One can be aware of facts and choose not to believe them.

What is the flaw in this example of implication:

Josefina believes there is an omnipotent robot overlord in charge of our daily lives. Robot overlords always wear neckties. Therefore, Josefina believes a necktie wearer is in charge of our daily lives.

When the conclusion adds she believes the premises, they are assuming too much. She may not be aware of the premises, or she may be and choose not to believe it.

Loophole for Implication

What if the person in question isn’t aware of what their belief implies.

False Dichotomy/Dilemma

Pretends there are only two options, when there could be more.

Two ways to go wrong:

• Limiting a spectrum

• Limiting options

Loophole for False Dichotomy/Dilemma

What if there are more than two options

Loophole for False Dichotomy/Dilemma (Limiting a Spectrum)

Not more ≠ less

Not less ≠ more

Example of False Dichotomy Limiting Options

My career options include becoming an astronaut and becoming a personal assistant. I’ve decided I’m afraid of space, so I’m going to be a personal assistant.

Example of False Dichotomy Limiting a Spectrum

The quality of the orange zest didn’t deteriorate overnight, so it must have improved

What is Straw Man

Arguments respond to an opponent by ‘mishearing’ what was said to them; they respond to something entirely different.

Often start with ‘so what you’re really saying is’; ‘so what you mean is’.

Opponent distorts the person’s point to make it easier to take the argument down.

Loophole for Straw Man

What if what they said has nothing to do with the claim they’re pretending to respond to?

Example of Straw Man

“we need to create a more reliable schedule for feeding the alligators in the preserve. It’s dangerous for us to enter the pen when the alligators are hungry”

“so what you’re really saying is that we should let the alligators get their own food whenever they want! That’s even more dangerous than leaving them hungry. I should give the alligators your job.”

What is the flaw in this example of straw man:

Student Rep: our university, in expelling a student who verbally harassed his roommate, has erred by penalizing the student for doing what he surely has a right to do: speak his mind!

Dean: But what you’re saying is that our university should endorse verbal harassment. Yet surely if we did that, we would threaten the free flow of ideas that is the essence of university life

The dean misdescribes the students reps position here. The student rep never mentioned verbal harassment. However, by bringing that up, the dean attacks the argument and gets away from addressing the actual point of the argument: expelling the student.

What is Ad Hominem

Insults the source of the argument, and then the conclusion challenges the truth of the position. However, the source does not impact the truth/falsity of the source’s position.

Essentially, attack on the person

Loophole for Ad Hominem

What if this person’s character/motivation doesn’t affect the truth.

What if the flaw in this example of Ad Hominem:

Isaac Newton destroyed the last known portrait of Robert Hooke, one of his intellectual rivals, so history would never know what Hooke looked like. He lied to Edmund Halley about having to ‘rework some figures’ so he could publish their shared work without having to credit Halley. Isaac Newton was a complete jerk. That’s why gravity is wrong.

Just because Isaac Newton is a bad person, does not invalidate the existence of gravity.

What is Circular Reasoning?

Assumes the conclusion is true before doing the work of proving it, ruling out any objections simply because the are incompatible with the conclusion.

The objection must not be true because it disproves the conclusion.

Circular arguments repeat their conclusion using synonyms, look out for synonyms.

Loophole for Circular Reasoning

What is we can’t use the conclusion as evidence for itself

Example of Circular Reasoning

Explaining circular reasoning is futile. Explaining complex concepts may seem a worthy aim. After all, it may be the only way to convey information. But since it will never work, there is no point.

What is the flaw in this example of circular reasoning:

Many people do not understand themselves, nor do they try to gain self-understanding. These people might try to understand others, but these attempts are sure to fail, because without self-understanding it is impossible to understand others. It is clear from this that anyone who lacks self-understanding will be incapable of understanding others.

The argument repeats things about self-understanding, repeating the conclusion twice.

What is Equivocation

Happens when the author changes the meaning of a word throughout an argument

Loophole for Equivocation

What if we shouldn’t let words change in meaning

What is the flaw in this example of Equivocation:

Our management consultant proposes that we reassign staff so that all employees are doing both what they like to do and what they do well. This she says, will ‘increase productivity by fully exploiting our available resources'.’ But Ace Manufacturing has a long-standing commitment not to exploit its workers. Therefore, implementing her recommendations would cause us to violate our own policy.

Exploit’s meaning changes. At first it means to use something to full extent, then it means to take advantage.

What is Appeal Fallacies

Turning an opinion into a fact. You cannot assume just cause someone in the stimulus says something is true, that it is true. Unless, it is an expert commenting on something in their field.

Can happen in two ways:

• Invalid appeal to authority

• Invalid appeal to public opinion

What is Invalid Appeal to Authority

Happens when the author uses a non-expert opinion to support their conclusion

Ex. zookeeper’s opinion cannot support a conclusion about baseball

What is Invalid Appeal to Public Opinion

Appeals to public opinion are invalid because people are unreliable

ex. a high % of people believing something has very little bearing on whether that thing is actually true

What is the flaw in this example of an appeal fallacy:

Most people believe that yawning is most powerfully triggered by seeing someone else yawn. This belief about yawning is widespread not only today, but also has been commonplace in many parts of the work in the past, if we are to believe historians of popular culture. Thus, seeing someone else yawn must be the most irresistible cause of yawning.

Nearly the exact same phrase is repeated in a premise and in the conclusion. The only difference is the premise stated the phrase as an opinion and the conclusion stated it as a fact. Never jump from conclusion to fact unless there is an expert opinion to back it up.

What is Irrelevant

Irrelevant occurs when the premises are entirely unrelated to the conclusion

Exploit gaps in the argument

Try every other applicable classic flaw before irrelavant

Loophole for Irrelavant

What is the premises and the conclusion have nothing to do with one another

What is the flaw in this example of irrelevant:

Manager: I will not order recycled paper for this office. Our letters to clients must make a good impression, so we cannot print them on inferior paper.

Supplier: recycled paper is not necessarily inferior. In fact, from the beginning the finest paper has been made of recycled material. it was only in the 1850’s that paper began to be made from wood fiber, and then only because there were no longer enough rags to meet the demand for paper.

The office manager is talking about a paper order, and the supplier starts talking about the history of paper. It is not related to the order, and therefore irrelevant. The supplier’s argument has nothing to do with the manager’s concern.

What is Percentages ≠ Numbers

A rising percentage doesn’t necessarily imply a rising number and vice versa

These arguments always assume the group size remains the same to keep the conclusion valid

Loophole of Percentages ≠ Numbers

Call out the group size, see if it is the same or not

What is the flaw in the example of Percentages ≠ Numbers:

A commonly accepted myth is that left-handed people are more prone to cause accidents than are right-handed people. But this is, in fact, just a myth, as is indicated by the fact more household accidents are caused by right-handed people than are caused by left-handed people.

There are a lot more righties in this world than lefties. It makes sense that the number of accidents caused by righties would be higher, even if the percentage of righties causing accidents is much lower.