Gas station owner: Increased fuel efficiency reduces air pollution and dependence on imported oil, which has led some people to suggest that automobile manufacturers should make cars smaller to increase their fuel efficiency. But smaller cars are more likely to be seriously damaged in collisions and provide less protection for their occupants. Greater fuel efficiency is not worth the added risk to human lives; therefore, manufacturers should not seek to increase fuel efficiency.

A
presumes, without providing justification, that it would be impossible to reduce the likelihood of dangerous accidents for small cars
The gas station owner never assumes this. In fact, she’s not talking about the likelihood of getting into an accident at all. She just claims that, when they are in accidents, smaller cars are more likely to be seriously damaged and so they pose a risk to human lives.
B
concludes, on the basis of the claim that one means to an end is unacceptable, that the end should not be pursued
The owner concludes, on the basis of the claim that making cars smaller to make them more fuel efficient is unacceptable, that manufacturers shouldn’t pursue increased fuel efficiency at all. But perhaps there are other ways to increase fuel efficiency that are perfectly safe.
C
draws a conclusion about what should be done from premises all of which are about factual matters only
The gas station owner does draw a conclusion about what should be done, but her premises are not all about factual matters only. The premise “greater fuel efficiency is not worth the added risk to human lives” is subjective.
D
presupposes the truth of what it sets out to prove
This is the cookie-cutter flaw of circular reasoning, in which the conclusion merely restates a premise. The gas station owner doesn’t make this mistake; her premises and conclusion are distinct.
E
presumes, without providing justification, that increasing fuel efficiency is the only way to reduce air pollution
The gas station owner says that increasing fuel efficiency reduces air pollution, but she never assumes that it’s the only way to reduce air pollution.

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If violations of any of a society’s explicit rules routinely go unpunished, then that society’s people will be left without moral guidance. Because people who lack moral guidance will act in many different ways, chaos results. Thus, a society ought never to allow any of its explicit rules to be broken with impunity.

Summarize Argument
The author concludes that a society should never allow any of its explicit rules to be broken without punishment. This is based on the fact that if violation of a society’s explicit rules ROUTINELY go unpunished, the people in society will be left without moral guidance, which ultimately leads chaos.

Identify and Describe Flaw
The author overlooks the possibility that allowing rules to SOMETIMES go unpunished doesn’t necessarily have the negative effects of allowing rules to ROUTINELY go unpunished. Routine non-punishments means regularly letting violations go unpunished. Chaos results if that happens. But chaos might not result if you just left a few violations go unpunished, without letting the nonpunishment become routine.

A
takes for granted that a society will avoid chaos as long as none of its explicit rules are routinely violated with impunity
The author never assumes that avoiding routine nonpunishment is sufficient to avoid chaos completely. There might be other causes that lead to chaos; the author’s simply recommending that we should avoid one thing that we know causes chaos.
B
fails to consider that the violated rules might have been made to prevent problems that would not arise even if the rules were removed
The purpose of the explicit rules is irrelevant, because the argument is based on the impact of routinely letting violations go unpunished. The purpose of the rules has no relationship to the fact that routine nonpunishment leads to chaos.
C
infers, from the claim that the violation of some particular rules will lead to chaos, that the violation of any rule will lead to chaos
The argument does not use a premise about some particular rules to reach a conclusion about any rules. Both the premise and conclusion are about any explicit rules.
D
confuses the routine nonpunishment of violations of a rule with sometimes not punishing violations of the rule
The premise concerns the effects of routine nonpunishment. But the author interprets this as a statement about the effects of sometimes not punishing. This is why the author believes society should not even allow a single instance of nonpunishment.
E
takes for granted that all of a society’s explicit rules result in equally serious consequences when broken
The argument is based on the fact the routine nonpunishment of any explicit rule leads to chaos. But the author is open to the idea that murder might be more serious than theft. What matters is that routine nonpunishment of either leads to chaos.

72 comments

Many successful graphic designers began their careers after years of formal training, although a significant number learned their trade more informally on the job. But no designer ever became successful who ignored the wishes of a client.

Summary
The stimulus can be diagrammed as follows:

Notable Valid Inferences
Some graphic designers with formal training do not ignore clients’ wishes.

Some graphic designers with informal training do not ignore clients’ wishes.

A
All graphic designers who are unsuccessful have ignored the wishes of a client.
This could be false. (A) says “/successful→Ignore client.” This is a confusion of the sufficient and necessary conditions of the relationship described in the stimulus.
B
Not all formally trained graphic designers ignore clients’ wishes.
This must be true. If we translate into lawgic, (B) says “formal ←S→ /ignore client.” As shown below, we see that there must be overlap between those two groups.
C
The more attentive a graphic designer is to a client’s wishes, the more likely the designer is to be successful.
This could be false. The argument does not distinguish between different levels of attention to clients, or different likelihoods of success. We just care about whether or not someone falls into these categories at all.
D
No graphic designers who learn their trade on the job will ignore clients’ wishes.
This could be false. (D) takes it too far. (D) says “informal→/ignore client.” We can’t support that conditional statement. We can just say that SOME who learn informally on the job won’t ignore client wishes; we can’t make this statement about everyone who learned informally.
E
The most successful graphic designers learn their trade on the job.
This could be false. Similar to (C), the stimulus does not make comparative statements. Since we don’t have any comparative evidence in the stimulus, we cannot make any comparative inferences about what the “most successful” designers do.

21 comments

Film critic: There has been a recent spate of so-called “documentary” films purporting to give the “true story” of one historical event or another. But most of these films have been inaccurate and filled with wild speculations, usually about conspiracies. The filmmakers defend their works by claiming that freedom of speech entitles them to express their views. Although that claim is true, it does not support the conclusion that anyone ought to pay attention to the absurd views expressed in the films.

Summary

There are a lot of purported “documentary” films that contain inaccurate accounts of historical events. Even though the filmmakers have the right to create these inaccurate films, that doesn’t mean anyone should pay attention to the views in those films.

Strongly Supported Conclusions

People can be entitled to create films that are inaccurate.

Some films contain views that people don’t need to pay attention to.

A
Although filmmakers are entitled to express absurd views, they are not justified in doing so.

This isn’t supported, because the author doesn’t suggest that the filmmakers were not justified in making their films. The author doesn’t suggest that they shouldn’t have made the films; only that people don’t need to pay attention to them.

B
Everyone ought to ignore films containing wild speculations about conspiracies.

This isn’t supported. The author doesn’t say that people should ignore the films. He just says that people don’t need to pay attention to them. “Shouldn’t do” and “don’t need to do” are different. Also, the facts only refer to “documentary” films, not all films with conspiracies.

C
Freedom of speech sometimes makes the expression of absurd views necessary.

Not supported, because the author doesn’t suggest that the filmmakers need to express the views in the films. They are entitled to do so, but that doesn’t mean they have to.

D
Freedom of speech does not entitle filmmakers to present inaccurate speculations as truth.

This is anti-supported, because the author says the filmmakers are entitled to make inaccurate films.

E
Views that people are entitled to express need not be views to which anyone is obliged to pay attention.

This is strongly supported by the last two sentences. The filmmakers are entitled to express their views, but that doesn’t imply people need to pay attention to them. So people need not (which means “don’t need to”) pay attention to hem.


4 comments

Health officials now recommend that people reduce their intake of foods that are high in cholesterol, such as red meat. The recent decline in the total consumption of beef indicates that many people are following this recommendation. But restaurants specializing in steak are flourishing despite an overall decline in the restaurant industry. So clearly there still are a lot of people completely ignoring the health recommendation.

A
It neglects to consider whether restaurants that specialize in steak try to attract customers by offering steak dinners at low prices.

It doesn’t matter how steak restaurants attract customers. Like (C), the author doesn’t need to explain why steak restaurants are flourishing. Instead, she needs to explain why the flourishing of these restaurants proves that many people are ignoring the health recommendation.

B
It assumes without warrant that people who eat steak at steak restaurants do not need to reduce their intake of foods that are high in cholesterol.

If anything, the author assumes that people who eat steak do need to follow the advice to reduce high-cholesterol food. People with low cholesterol might be intentionally eating steak, but (B) doesn’t make this attack. Either way, they would still be ignoring the recommendation.

C
It presupposes that the popularity of restaurants that specialize in steaks is a result of a decrease in the price of beef.

The author doesn’t assume that beef prices dropped or that this caused steak restaurants to be popular. Like (A), she doesn't need to explain why these restaurants are thriving. Instead, she needs to explain how their success shows that many people are ignoring the health advice.

D
It mistakes the correlation of the decline in beef consumption and the decline in the restaurant industry for a causal relation.

The author never assumes that the decline in beef consumption caused the decline in the restaurant industry or vice versa.

E
It fails to consider whether the people who patronize steak restaurants have heeded the health officials by reducing their cholesterol intake in their at-home diets.

The author draws a conclusion about overall eating habits from one instance of eating high-cholesterol food. She assumes that since people go to steak restaurants, they’re ignoring the advice to avoid high-cholesterol food. But they might follow that advice in their other meals.


19 comments

With decreased production this year in many rice-growing countries, prices of the grain on world markets have increased. Analysts blame this increase on the fact that only a small percentage of world production is sold commercially, with government growers controlling most of the rest, distributing it for local consumption. With so little rice being traded freely, even slight changes in production can significantly affect the amount of rice available on world markets.

Summarize Argument: Phenomenon-Hypothesis
The phenomenon is that world rice production decreased and prices increased. Analysts hypothesize that the price increase is due to the fact that most of the world's rice is controlled by governments and distributed for local use, with only a small portion being sold commercially. Because so little rice is sold commercially, minor fluctuations in production can significantly impact market supply.

Notable Assumptions
The analysts assume that because only a small amount of rice is sold commercially, it must be that a decrease in market supply caused the price increase. In other words, the analysts assume that no other factor could have caused the price increase.

A
Rice-importing countries reduce purchases of rice when the price increases dramatically.
This doesn’t affect the analysts’ explanation. (A) discusses how rice-importing countries react to price increases, but not the cause of the price increase, which is what the analysts’ explanation is about.
B
In times of decreased rice production, governments store more of the rice they control and reduce their local distribution of rice.
This doesn’t affect the analysts’ explanation. Governments choosing to store and reduce their distribution of rice should not impact market dynamics (i.e., price increases) because the rice they control was never part of the market anyway.
C
In times of decreased rice production, governments export some of the rice originally intended for local distribution to countries with free grain markets.
This weakens the analysts’ explanation. It challenges the assumption that the price increase is due to limited market supply by introducing the idea that, in periods of low production, world market supply is supplemented by governments who usually distribute their supply locally.
D
Governments that distribute the rice crop for local consumption purchase the grain commercially in the event of production shortfalls.
This strengthens the analysts’ explanation. It indicates that when supply is limited, governments who distribute rice locally turn to the world market for additional supply, strengthening the idea that periods of low production can greatly affect the world market supply of rice.
E
During reduced rice harvests, rice-importing countries import other kinds of crops, although this fails to compensate for decreased rice imports.
This does not affect the analysts’ explanation, which discusses how the world market supply of rice affects the price of rice—other kinds of crops are not relevant.

30 comments