People ought to take into account a discipline’s blemished origins when assessing the scientific value of that discipline. Take, for example, chemistry. It must be considered that many of its landmark results were obtained by alchemists—a group whose superstitions and appeals to magic dominated the early development of chemical theory.

Summarize Argument
The author concludes that, when assessing a discipline's scientific value, people should consider that discipline’s blemished origins. He points to chemistry as an example, noting that many important discoveries were made by alchemists, whose superstitions and belief in magic shaped early chemical theory.

Identify and Describe Flaw
The author concludes that people should consider a discipline’s blemished origins when assessing that discipline’s scientific value. But he fails to consider whether those origins are relevant to how the discipline functions today. To use his example, what if chemistry today is entirely different from chemistry as practiced by the alchemists? In that case, why should we consider the alchemists when judging chemistry’s current scientific value?

A
fails to establish that disciplines with unblemished origins are scientifically valuable
The author never assumes that disciplines with unblemished origins are scientifically valuable. He just argues that blemished origins should be considered when assessing a discipline’s scientific value.
B
fails to consider how chemistry’s current theories and practices differ from those of the alchemists mentioned
The author fails to consider the possibility that alchemists’ practices are entirely different from current chemistry practices and so perhaps should not be considered when assessing chemistry’s scientific value.
C
uses an example to contradict the principle under consideration
The author does use an example, but he uses it to support the principle under consideration, not to contradict it.
D
does not prove that most disciplines that are not scientifically valuable have origins that are in some way suspect
The author never assumes that disciplines that are not valuable have suspect origins, so he doesn’t need to prove this. He doesn’t say how a discipline’s origins affect its scientific values, only that its origins should be considered when assessing its value.
E
uses the word “discipline” in two different senses
This is the cookie-cutter flaw of “equivocation.” The author doesn’t make this mistake because he uses the word “discipline” consistently throughout his argument.

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Editorial: The government claims that the country’s nuclear power plants are entirely safe and hence that the public’s fear of nuclear accidents at these plants is groundless. The government also contends that its recent action to limit the nuclear industry’s financial liability in the case of nuclear accidents at power plants is justified by the need to protect the nuclear industry from the threat of bankruptcy. But even the government says that unlimited liability poses such a threat only if injury claims can be sustained against the industry; and the government admits that for such claims to be sustained, injury must result from a nuclear accident. The public’s fear, therefore, is well founded.

Summary

The government claims that there will be no nuclear accidents. It also claims that it must protect the nuclear industry from the threat of bankruptcy posed by unlimited liability—the claims that follow are shown in the diagram below.

Notable Valid Inferences

The government’s position is inconsistent. We can see this by taking the contrapositive of the conditional relationship in the stimulus. The contrapositive shows that if there is no potential for injuries from a nuclear accident (which is what the government claims), unlimited liability does not pose a threat. However, the government also claims that unlimited liability does pose a threat. These two claims are incompatible.

A
The government’s claim about the safety of the country’s nuclear power plants is false.

This could be false. We know the government’s position is contradictory, but we don’t know which of its claims are true. It could be that the plants are safe and the government is incorrect to claim that unlimited liability poses a threat to the nuclear industry.

B
The government’s position on nuclear power plants is inconsistent.

This must be true. It cannot both be true that there is no potential for nuclear accidents and unlimited liability poses a threat to the nuclear industry.

C
The government misrepresented its reasons for acting to limit the nuclear industry’s liability.

This could be false. We know the government’s position is contradictory, but we don’t know which of its claims are true. It could be that the government wants to protect the industry from bankruptcy and it instead misrepresented how safe the nuclear power plants actually are.

D
Unlimited financial liability in the case of nuclear accidents poses no threat to the financial security of the country’s nuclear industry.

This could be false. The government claims that unlimited financial liability is a threat to the financial security of the nuclear industry. We don’t know for sure whether this claim is correct or not, only that the government made this claim.

E
The only serious threat posed by a nuclear accident would be to the financial security of the nuclear industry.

This could be false. The stimulus does not suggest that nuclear accidents do not threaten physical health or safety—it says that the government claims nuclear accidents won’t happen in the first place.


49 comments

The higher the average fat intake among the residents of a country, the higher the incidence of cancer in that country; the lower the average fat intake, the lower the incidence of cancer. So individuals who want to reduce their risk of cancer should reduce their fat intake.

Summarize Argument: Phenomenon-Hypothesis
The author concludes that eating less fat will help reduce cancer risk. He supports this by pointing to a correlation between cancer rates and fat intake: countries with higher cancer rates also have higher average fat intake.

Notable Assumptions
Based on a mere correlation, the author hypothesizes that higher fat intake is what’s causing the higher cancer rates. This means he assumes that the relationship isn’t the reverse (i.e., the higher cancer rates aren’t somehow causing higher fat intake), and also that there isn’t some hidden, alternative cause that’s actually responsible for the difference in cancer rates between different countries.

A
The differences in average fat intake between countries are often due to the varying makeup of traditional diets.
In order for this to weaken the argument, traditional diets would need to provide an alternative explanation for the difference in cancer rates between different countries. However, the possible effect of any given traditional diet on cancer rates is entirely unclear.
B
The countries with a high average fat intake tend to be among the wealthiest in the world.
In order for this to weaken the argument, the wealth of a country would need to provide an alternative explanation for the increased cancer rates in high-fat counties. However, the connection between increased national wealth and increased cancer likelihood is entirely unclear.
C
Cancer is a prominent cause of death in countries with a low average fat intake.
The stimulus tells us that cancer nevertheless occurs more commonly in countries with higher average fat intake. (C) fails to address any reason for that difference in cancer rates, and so fails to weaken the conclusion that the difference is due to fat intake.
D
The countries with high average fat intake are also the countries with the highest levels of environmental pollution.
This provides an alternative cause for the difference in cancer rates between different countries: it’s not fat intake that’s responsible, but rather exposure to pollution.
E
An individual resident of a country whose population has a high average fat intake may have a diet with a low fat intake.
The fact remains that, in general, high average fat intake correlates with high cancer rates. The possibility that someone’s fat intake might deviate from the average has no effect on the argument.

207 comments