Summarize Argument: Phenomenon-Hypothesis
The representatives hypothesize that the deformity in bluefin cod was caused by the chemical waste dumped into Cod Bay. This is because those chemicals are known to cause genetic mutations.
Notable Assumptions
Based on a mere correlation, the representatives assume that the presence of chemicals caused the deformity in bluefin cod. This means the representatives don’t believe some third factor in fact caused the deformity, and that the deformity rates didn’t in fact precede the chemical waste being dumped in Cod Bay.
A
What is the incidence of deformed fins in bluefin cod that are not exposed to chemicals such as those dumped into Cod Bay?
If the incidence of deformity in bluefin cod is generally 3%, then it would seem the chemicals made no difference—a weakener. If the incidence was generally 0%, then the chemicals (or some other factor) would explain the 3% rate in Cod Boy—a strengthener.
B
What was the incidence of deformed fins in bluefin cod in Cod Bay before the chemical dumping began?
If the incidence of deformity in bluefin cod was 3% before chemical dumping, then it would seem the chemicals made no difference—a weakener. If the incidence was 0% before dumping, then the chemicals would explain the 3% rate in Cod Boy—a strengthener.
C
Has the consumption of the bluefin cod from Cod Bay that have deformed fins caused any health problems in the people who ate them?
We don’t care about how these deformities impact human health. The representatives hypothesize about what caused the deformities in the first place.
D
Are bluefin cod prone to any naturally occurring diseases that can cause fin deformities of the same kind as those displayed by the bluefin cod of Cod Bay?
If the answer is yes, then these diseases rather than the chemical may have been responsible for the deformities. If the answer is no, then chemicals remain a highly viable explanation of the deformities.
E
Are there gene-altering pollutants present in Cod Bay other than the chemical wastes that were dumped by the companies?
This points to an alternate cause. If other pollutants can cause deformities, then chemical waste might not be to blame. If other pollutants can’t cause deformities, chemical waste remains a highly viable explanation.
Summarize Argument
The columnist concludes that it is reasonable to doubt statements from anonymous sources in news stories. To support this position, the columnist draws an analogy to doubting the truth of an unsigned letter, reasoning that in either case, anonymity gives a writer more freedom to speak dishonestly without worrying about personal consequences.
Describe Method of Reasoning
The columnist concludes that a response is reasonable in one case by offering an analogous case where that response is considered reasonable, and showing that the response can be justified by the same reasoning in both cases.
A
pointing out that a certain attitude would presumably be adopted in one situation, in order to support the claim that a similar attitude would be justified in an analogous situation
The attitude of doubt adopted in the situation of receiving an unsigned letter is used to justify an attitude of skepticism toward reading statements from anonymous sources in newspapers—two situations presented as analogous.
B
drawing an analogy between an attitude commonly adopted in one situation and a different attitude commonly adopted in another situation, and establishing that the latter attitude is better justified than the former
The columnist doesn’t argue about different attitudes being adopted in two different situations. Rather, the columnist argues that the same attitude should be adopted in analogous situations.
C
inferring that an attitude would be justified in all situations of a given type on the grounds that this attitude is justified in a hypothetical situation of that type
The columnist doesn’t make any generalizations about a “type” of situation, only justifying one situation—doubting anonymous sources in newspapers—using another, analogous situation of doubting the contents of unsigned letters.
D
calling into question a certain type of evidence by drawing an analogy between that evidence and other evidence that the argument shows is usually false
The columnist isn’t showing that any evidence is false, instead only arguing that it is reasonable to doubt statements from certain sources by comparing them to analogous sources that are usually doubted—not shown to be false.
E
calling into question the motives of those presenting certain information, and concluding for this reason that the information is likely to be false
The columnist doesn’t conclude that any information is likely to be false, only concluding that skepticism about some information is justified.