Logical Reasoning Flaw Questions in the News

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Manhattan Prep LSAT Blog - Logical Reasoning Flaw Questions in the News by Patrick Tyrrell

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1/6 of our questions in Logical Reasoning are Flaw questions, and about 45-50% of the answer choices in Logical Reasoning Flaw questions (over the past ten tests) refer to one of these 10 Famous Flaws:

  • Conditional Logic (Necessary vs. Sufficient)
  • Part vs. Whole
  • Correlation vs. Causality
  • Unproven vs. Untrue
  • Sampling
  • Ad Hominem (Attacking the Source, not the Content)
  • Appeal to Inappropriate Authority
  • Two Different Meanings (Equivocation)
  • Circular (Assumes the Conclusion / Premise Restates the Conclusion)
  • Internal Contradiction (Inconsistent claims)

Since so many answer choices are going to be alluding to these same ten flaws, it’s valuable to really understand the flaws. The better we know what they are, the easier it is to see when they aren’t occurring, and so that makes evaluating 45-50% of the answer choices much easier!

Here are ten political arguments, each one exhibiting a different Logical Reasoning flaw on the list. See if you can match them up.

(And call off your dogs… these arguments don’t reflect our editorial views. This is good practice to stay intellectually disciplined. Some of these premises will sound partisan, but we’re not here to fight premises. We’re here to analyze reasoning. The problems we’re trying to identify relate to The Move from evidence to conclusion. Focus on that.)

1. CNN has suggested that candidates be held more responsible for their statements by adding a “realtime fact checking” component to future debates. However, we can safely ignore this idea, given that CNN has frequently been guilty of factual inaccuracies in its own reporting.

2. President Trump is clearly inept at foreign policy. His erratic confrontations with North Korea led to a sudden switch in tone from the North Koreans and a welcome chance to open direct talks, but this result was only a lucky happenstance, since the President is too poor at foreign policy to have planned this chain of events.

3. People agitating for gun control measures such as universal background checks claim that these restrictions would not impinge upon the 2nd Amendment, but obviously they are trying to take our guns away. For in the very name ‘gun control’, it betrays their desire to have control of our guns.

4. President Trump recently proposed enacting tariffs on imported steel and aluminum, to improve the business position of the American steel and aluminum manufacturers. Although opponents of the action point out that it will raise the price of many domestic goods that use steel and aluminum, it is clear that tariffs are popular with the American worker, as a recent poll found that 76% of steel and aluminum workers support the measure.

5. Only those who are in the top 1% of wealth will see long term benefit from the new tax plan. Anyone who sees long term benefit from the new tax plan will support it. Thus, if someone is attacking the new tax plan, then they are clearly not in the top 1% of wealth.

6. Trump is the worst person who has ever been and who could ever be President. But if he were to be removed from office, then we’d be stuck with Mike Pence, who is also a disaster. Hence, we’re better off just having Trump be President.

7. The Environmental Protection Agency (EPA) and the scientific community have been overblowing the potential danger and extent of climate change. We know this because in numerous surveys encompassing a diverse group of Americans, a consistent majority of respondents believe that the climate is “not currently in crisis.”

8. The FBI’s probe into Russian interference in the 2016 election reveals that as Russian “trolling” activity picked up in the summer of 2016, Trump’s popularity rose and his opponent’s popularity fell. Clearly, this meddling from Moscow had a critical effect on the election results.

9. Special Counsel Robert Mueller has been investigating connections between Russia and the Trump campaign leading up to the 2016 election. Since the investigation has not found any evidence of collusion, we can be sure that there was not any collusion.

10. The US Congress works slowly, often irrationally, and with constant partisan bickering. Therefore, Lindsay Graham, a US congressperson, works slowly, often irrationally, and with constant partisan bickering.

Wow, wasn’t that excruciating? You went to your favorite LSAT blog as an escape from the political stories flooding your Twitter and Facebook feeds. Okay, let’s see how we did.

ANSWERS

1. CNN has suggested that candidates be held more responsible for their statements by adding a “real-time fact checking” component to future debates. However, we can safely ignore this idea, given that CNN has frequently been guilty of factual inaccuracies in its own reporting.

AD HOMINEM
(rejects an idea based on its source, not its content)

One of the most beautiful habits the LSAT trains us to possess is to evaluate ideas on their own merit, regardless of whether they’re being offered by people who are potentially biased, have an ulterior motive, or have behaved in the past in ways that conflict with their current advice. Maybe your ex doesn’t believe that you can change, but the LSAT does.  

So what if CNN has been guilty of factual inaccuracies in the past? Maybe they’ve turned over a new leaf or reminded themselves of the definition of ‘journalism.’ And even if CNN is still veracity-challenged, is their proposal any good? If we’re hatin’ on Ted Turner’s Newsertainment Revue (CNN) because CNN has been a half-truth disseminating enterprise in the past, then we clearly hate the dissemination of half-truths. Well, political debates are full of half-truths, and since many people don’t get a chance to fact-check the debate later, then wouldn’t real-time fact-checking help to thwart the dissemination of half-truths? We should be liking CNN’s idea for the same reason we might not like CNN. We can’t be dismissive of ideas (“we can safely ignore this idea”) just because they’re coming from a potentially dubious source.

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2. President Trump is clearly inept at foreign policy. After all, his erratic confrontations with North Korea led to a sudden switch in tone from the North Koreans and a welcome chance to open direct talks, but this result was only a lucky happenstance, since the President is too poor at foreign policy to have planned this chain of events.

CIRCULAR REASONING
(the argument assumes what it sets out to prove / the conclusion is a restatement of one of the premises)

An author who’s guilty of circular reasoning doesn’t seem to have the capacity to consider possibly disconfirming evidence. “Chocolate is clearly the best flavor of ice cream, because if you consider all the other flavors, there just aren’t any flavors that are better than chocolate.”

This author believes that Trump is bad at foreign policy, and when he looks at a possibly disconfirming piece of evidence (the positive breakthrough of direct talks with North Korea), he stays determined to interpret this evidence through his pre-existing belief that Trump is bad at foreign policy.

Maybe Trump really did have a master plan. Maybe his years of negotiating deals have given him strong intuitive abilities to read his adversaries, and maybe Trump has had ample opportunities to experiment with unorthodox methods of negotiating.

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3. People agitating for gun control measures such as universal background checks claim that these restrictions would not impinge upon the 2nd Amendment, but obviously they are trying to take our guns away. For in the very name ‘gun control,’ it betrays their desire to have control of our guns.

EQUIVOCATION
(the argument uses the term “gun control” in two different ways)

When a Logical Reasoning flaw answer choice puts a term in quotes and accuses the author of shifting meanings, it’s probably an incorrect answer choice. This is very rarely the actual flaw. In order to feel good about picking such an answer, you should be able to define the word/idea in question in two completely different ways. For this argument, we can do just that:

Usage 1: “gun control” = universal background checks (controlling who is allowed to purchase guns)
Usage 2: “gun control” = taking someone’s guns away

This type of willful obfuscation of language is poisonous in our political discourse. It is similar to the idea of Straw Man, where you’re responding to a different position than the one actually offered. The Straw Man is an exaggerated version of the claim actually offered, so it’s an easy claim to defeat (a straw man is easy to bring down).  

Person 1: We should try to enact some additional constraints on gun ownership in an attempt to reduce the incidence/severity of mass shootings.
Person 2: No gun law is going to prevent all mass shootings. What we should REALLY be talking about is…

I want to suggest a Grand Bargain for liberals and conservatives:

CONSERVATIVES, you can’t have an absolutist position on current gun laws. There’s no way they’re currently perfect. We should be allowed to discuss possible changes to them without you freaking out and thinking we’re rescinding the 2nd Amendment.

LIBERALS, you can’t have an absolutist position on immigration laws. There’s no way they’re currently perfect. We should be allowed to discuss possible changes to them without you freaking out and thinking that we’re sending back the Statue of Liberty.

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4. President Trump recently proposed enacting tariffs on imported steel and aluminum, to improve the business position of the American steel and aluminum manufacturers. Although opponents of the action point out that it will raise the price of many domestic goods that use steel and aluminum, it is clear that tariffs are popular with the American worker, as a recent poll found that 76% of steel and aluminum workers support the measure.

SAMPLING

When arguments lean on a survey or sample, we want to ask ourselves a couple basic questions:
– is it a sufficiently large (at least 100 people) and diverse (i.e. representative) sample of people?
– do we have a reason to think their answers might be biased or pressured in some way?

A sampling flaw is only occurring when the conclusion speaks for a bigger group than the sample does.

f.e. if the conclusion had been “It is clear that tariffs are popular with the American steel worker,” it would be a much safer inference.
f.e. if the conclusion had been “It is clear that tariffs are popular with some American workers,” it would be a good inference.

A Sampling Logical Reasoning flaw can feel a lot like a Comparison Flaw. By concluding something about “the American worker” on the basis of a poll about “steel and aluminum workers,” we’re assuming that the average American worker is fair to compare to steel and aluminum workers. (The Comparison Flaw is that the author fails to recognize a key difference between the two groups.)

In this argument, the key difference is that steel and aluminum workers will disproportionately benefit from tariffs, whereas other workers are more likely to see some financial harm in the form of higher costs on certain goods.

If you’re trying to assess the popularity of a measure, you should definitely consider those it benefits and those it harms.

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5. Only those who are in the top 1% of wealth will see long term benefit from the new tax plan. Anyone who sees long term benefit from the new tax plan will support it. Thus, if someone is attacking the new tax plan, then they are clearly not in the top 1% of wealth.

CONDITIONAL LOGIC FLAW (aka “Necessary vs. Sufficient”)

If we’re reading a Logical Reasoning Flaw question and we see any conditional language (such as the “if” and “any” I just uttered), we need to start assuming that they’re testing Conditional Logic flaws. Here, the conditional giveaway words were only, anyone, and if.

If X, then Y” =  X —> Y
Only if X, then Y” =  Y —> X  

It’s very important to differentiate between these two. This is where many, if not most, of the conditional logic errors come from.

“Only” and “Only if” work the same way. They always introduce the right side idea, so we can draw an arrow through only / only if, to remind ourselves that what follows those words belongs on the right side of the arrow.

“-o-n-l-y—> those who are in top 1% will see long term benefit” = long term benefit –> in top 1%

Anyone is a universal, just like all, any, each, every, no, none. When you have a universal idea, it goes on the left.

“Anyone with long term benefit will support tax plan” = long term benefit —> support tax plan

When we have multiple conditionals, we ask ourselves, “Can these chain together?” (We may have to contrapose one of them to see the possible chain)

Chains happen when you have the opposite idea in the same place
    X  –> Y
  ~X –> Z
gives you
 ~Y –> ~X –> Z

or chains happen when you have the same idea in opposite places
   X –> Y
   Z –> X
gives you
   Z –> X –> Y

Can we chain together these two conditionals?
long term benefit –> in top 1%
long term benefit –> supports tax plan

No, because they have the same idea in the same spot. Meanwhile, the author’s conclusion acts like we can chain them together, because it’s saying “if not supports tax plan, then not in top 1%.” We should contrapose our two given conditionals so that we can better spot the illegal move the author is making.

not in top 1% –> not long term benefit
not supports tax plan –> not long term benefit

If our author’s conclusion is “if not supports tax plan, then not in top 1%,” then she’s picturing this logic train:

“if not supports tax plan, not long term benefit. if not long term benefit, then not in top 1%.”

The first half there is legitimate. The second half is going the wrong way. We can say to ourselves, “The author is botching that first conditional, the one connecting long term benefit to top  1%.”

We would be able to correctly describe the flaw by using necessary vs. sufficient language.

(A) the author treats a condition that guarantees membership in the top 1% as though it is required for membership in the top 1%

or we could correctly describe the flaw by showing a potential counterexample.

(A) the author fails to consider that some people might be in the top 1% but not receive long term benefit from the tax plan

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6. Trump is the worst person who has ever been and who could ever be President. But if he were to be removed from office, then we’d be stuck with Mike Pence, who is also a disaster. Hence, we’re better off just having Trump be President.

INTERNAL CONTRADICTION
(the author presents claims that are inconsistent with each other)

This famous Logical Reasoning flaw (just like Circular Reasoning and Equivocation) is very rare, although LSAT has tested it at least once on a recent test.

If Trump were really ‘the worst there ever was or will be,’ then ANYONE ELSE would be better. Hence, the conclusion’s notion that we’d be better off keeping Trump as President contradicts something she earlier said. In real life, you hear many exasperated liberals make arguments similar to this one. i.e., “Trump is the worst. But if we got rid of him, we’d have Pence, who’s just as bad.” It’s possible that Trump and Pence are tied for the worst, but that doesn’t seem to be the thinking here. It feels more like a desire to complain is making someone say, “Don’t bother trying to make me feel better… I’m still gonna be mad.”

A very common distinction that LSAT tests is the difference between Relative vs. Absolute. Perhaps Trump and Pence are both unappealing to liberals as options for our President (“unappealing” = absolute). But it’s possible that Trump is more unappealing than Pence (“more unappealing” = relative).

Someone who argues with the defeatist logic of “What’s the point of ousting Trump? His replacement would also be bad” basically thinks that losing $10,000 is the same as losing $1,000. Yes, they’re both bad outcomes, but isn’t one worse?

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7. The Environmental Protection Agency (EPA) and the scientific community have been overblowing the potential danger and extent of climate change. We know this because in numerous surveys encompassing a diverse group of Americans, a consistent majority of respondents believe that the global climate is “not currently in crisis”.

APPEAL TO INAPPROPRIATE AUTHORITY

The author argues that the EPA and the scientific community are wrong about climate change because most Americans believe that we’re not experiencing a global climate crisis. No offense, most Americans, but do you guys have any idea what you’re talking about? Climate science is about as complex a scientific undertaking as there is. It takes professionals years of studying and training to make sense of the available climate data. Have most Americans put in that time? Do they even understand the critical difference between their local weather and the global climate?  

This argument advertises that it probably does NOT have a Sampling Flaw, because it reassures us that we have numerous surveys (decent sample size) with a diverse group of Americans (representative sample).

Appeal to Inappropriate Authority is a pretty rare Logical Reasoning flaw (both in terms of showing up as the genuine problem with the argument and in terms of showing up in incorrect answer choices). It has some close cousins: authors may appeal to people whose expertise has not been demonstrated, or authors may appeal to majority opinion as though that counts as fact, or authors may appeal to emotion in a matter that is purely factual.

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8. The FBI’s probe into Russian interference in the 2016 election reveals that as Russian “trolling” activity picked up in the summer of 2016, Trump’s popularity rose and his opponent’s popularity fell. Clearly, this meddling from Moscow had a critical effect on the election results.

CORRELATION vs. CAUSALITY

Getting better at spotting this flaw is mainly about developing an ear for Correlation language. The most common phrasings are:

People who are X are more likely than those who aren’t to be Y
People who are X tend to be Y
X happened. Then Y happened.
As X was happening, Y was happening.

Here, the author is arguing that “as more Russian trolling was happening, Trump was getting more popular and Hillary was getting less popular.” Does that mean that the first thing caused the second thing?

Maybe, but not necessarily. LSAT bristles against the overconfident certainty with which authors declare their causal conclusions. Had the argument merely concluded, “Clearly, this meddling from Moscow may have had some effect on the election results,” it would be a responsible conclusion.

When authors are overly sure about one possible way to interpret the background data, LSAT wants us to point out or entertain other possible ways to explain the same data.  

Maybe Russian trolling had an uptick in July, at the same time as the Republican Convention. The pro-Trump and anti-Hillary speeches at the Republican Convention may have been the real causal reason for the shift in polling numbers, and the increase in Russian trolling at the same time was just a coincidence.

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9. Special Counsel Robert Mueller has been investigating connections between Russia and the Trump campaign leading up to the 2016 election. Since the investigation has not found any evidence of collusion, we can be sure that there was not any collusion.

UNPROVEN vs. UNTRUE

Just because someone has failed to prove X, or has offered an inadequate argument in favor of X, does not mean that we can conclude, with certainty, that X is false. Even if Mueller’s investigation fails to find any evidence, that doesn’t prove that no evidence exists. (It just highly suggests we should move on with our lives.)

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10. The US Congress works slowly, often irrationally, and with constant partisan bickering. Therefore, Lindsay Graham, a US congressperson, works slowly, often irrationally, and with constant partisan bickering.

PART vs. WHOLE

We shouldn’t infer that because a collective has a given trait, each part of that collective shares the same trait (or vice versa). In this argument, we inferred that Lindsay Graham would be slow, irrational, and bickering on the basis of knowing that a group to which he belongs (Congress) is a slow, irrational, bickering group.

When we move from Part to Whole, or from Whole to Part as we did here, we’re really ignoring how group dynamics can result in emergent traits that differ from the underlying parts. We’re also failing to consider how individual parts of a group may be outliers and exceptions, but they are drowned out by the majority so “the group” doesn’t resemble the same qualities as the outliers. Part to Whole should be renamed “The All-Star Team Fallacy.” Just because you have the best players doesn’t mean you have the best teamAnd even though Congress is a slow, bickering group, Lindsey Graham might be an efficient, congenial member. They call him “Ol’ Golden Grahams” around the Capitol.

Whole to Part thinking is a pernicious force behind our growing political divisiveness. When we lump ALL Democrats or ALL Republicans together, we’re unfairly assuming that anyone accepting either group label automatically subscribes to the beliefs/behaviors we associate with that group. With that sort of dismissive, lazy, stereotyping thinking, we stop considering politicians on a case-by-case basis, and so we stop encouraging the Republicans we most like and the Democrats we most like. When Americans used to be more willing to “split the ticket” (i.e. I’m a Republican, but this Democrat is cool with me), we seemed to have a more centrist, civil, functional political discourse.

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We came here to practice our ten famous flaws, and I couldn’t resist submitting a plea for civil centrism by the end.

It’s up to you LSAT students and future lawyers to remind the world how to moderate your language and how to resist the temptation to argue claims that exceed your available evidence. 📝


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patrick-tyrrellPatrick Tyrrell is a Manhattan Prep instructor based in Los Angeles, California. He has a B.A. in philosophy, a 178 on the LSAT, and relentless enthusiasm for his work. In addition to teaching test prep since 2006, he’s also an avid songwriter/musician. Check out Patrick’s upcoming LSAT courses here!

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