Summarize Argument: Phenomenon-Hypothesis
Scientists hypothesize male sage grouse inflate their air sacs during a courting ritual so that female sage grouse can select healthy mates. They provide no evidence for this claim.
Notable Assumptions
The scientists assume that inflated air sacs either signify health in themselves, or demonstrate some feature that signify health. They also assume female sage grouse can determine which males are healthy and which aren’t. Lastly, the scientists assume the female sage grouse are more likely to choose the healthy males.
A
Some female sage grouse mate with unhealthy male sage grouse.
This is irrelevant. Perhaps those were the only unhealthy male sage grouse left.
B
When diseased male sage grouse were treated with antibiotics, they were not selected by female sage grouse during the courtship ritual.
We have no idea what effect antibiotics have.
C
Some healthy male sage grouse do not inflate their air sacs as part of the courtship ritual.
Are those males chosen by the females? We would need to know in order for this to be a strengthener.
D
Male sage grouse are prone to parasitic infections that exhibit symptoms visible on the birds’ air sacs.
Females can note parasitic infections when male sage grouse inflate their air sacs. Thus, they are quite likely looking to see which males are healthy during the courting ritual.
E
The sage grouse is commonly afflicted with a strain of malaria that tends to change as the organism that causes it undergoes mutation.
This has nothing to do with air sacs.
Speaker 1 Summary
Some writers explain Stalin’s misdeeds by characterizing his sanity during his later years as “paranoia” and “morbid suspiciousness.” However, Stalin’s cruelty was not more apparent during his later years than it was during the earlier periods of his rule. “Morbid suspiciousness” is a required characteristic for tyrants, because without it they would not remain in power.
Speaker 2 Summary
Objective
We need a statement that the critic and writers disagree on. They disagree whether certain characteristics of Stalin could explain why he was such a cruel leader. The writers think that Stalin’s characteristics could explain his misdeeds, while the critic thinks that Stalin was always a cruel leader.
A
whether Stalin should be held guilty of the cruel deeds attributed to him
Neither speaker expresses an opinion on this statement. We don’t know whether either speaker believes Stalin should be held guilty.
B
whether Stalin’s cruel misdeeds provide evidence of morbid suspiciousness
Neither speaker expresses an opinion on this statement. The writers would think the opposite relationship is true. For the writers, Stalin’s morbid suspiciousness explain his cruel misdeeds.
C
whether it is Stalin’s state of paranoia or rather his cruelty that gives the stronger reason for doubting his sanity
Neither speaker expresses an opinion on this statement. Neither speaker addresses whether it’s more likely paranoia or cruelty explain Stalin’s sanity.
D
whether tyranny tends to lead to cruelty
Neither speaker expresses an opinion on this statement. Only the critic addresses tyranny, and the critic does not conclude that tyranny usually leads to cruelty.
E
whether it was Stalin’s psychological state or rather his political condition that was the primary cause of his cruel misdeeds
The critic and the writers disagree on this statement. The writers agree that Stalin’s psychological state explain his cruel misdeeds, while the critic would agree that Stalin’s political status explain his cruel misdeeds.
Summarize Argument: Phenomenon-Hypothesis
The scientist hypothesizes Alzheimer’s disease is caused by a virus. This is based on a study where rats injected with blood from Alzheimer’s disease patients exhibited signs of a different neurological disorder which is caused by a virus.
Notable Assumptions
The scientist assumes that the rats developed Creutzfeldt-Jakob disease due to being injected blood from Alzheimer’s disease patients; if that virus came from elsewhere, then the hypothesis makes no sense. The scientist also assumes that the same virus that causes Creutzfeldt-Jakob disease causes Alzheimer’s disease. It would otherwise be purely coincidental that Alzheimer’s patients carry two separate disease-causing viruses.
A
Alzheimer’s disease in rats is not caused by a virus.
We have no evidence rats can even get Alzheimer’s. If anything, this seems to weaken the scientist’s argument.
B
Creutzfeldt-Jakob disease affects only motor nerves in rats’ limbs, not their brains.
We don’t care about how the disease affects rats. We care about where Creutzfeldt-Jakob disease came from.
C
The virus that causes Creutzfeldt-Jakob disease in rats has no effect on humans.
If it has no effect on humans, then it couldn’t cause Alzheimer’s disease. This weakens the scientist’s argument.
D
The symptoms known, respectively, as Creutzfeldt-Jakob disease and Alzheimer’s disease are different manifestations of the same disease.
Creutzfeldt-Jakob disease and Alzheimer’s disease are the same disease. Thus, a virus that causes one must cause the other, and we know that Creutzfeldt-Jakob disease in rats was caused by a virus.
E
Blood from rats without Creutzfeldt-Jakob disease produced no symptoms of the disease when injected into other experimental rats.
We need to strengthen the connection between a virus and Alzheimer’s disease. We can imagine rats without a virus don’t infect other rats.