Summarize Argument
An organization sent a fund-raising letter to 5,000 people. The author concludes that most of the 5,000 people to whom the letter was sent agreed with the organizaton’s position on a particular social issue. This is supported by results of a survey that was sent with the letter. Out of the 300 who responded to the survey, 283 responded that they agreed with the organization.
Identify and Describe Flaw
The author overlooks the possibility that the people who responded to the survey are unrepresentative of the people who didn’t respond to the survey with respect to their opinion on the issue. It’s possible that the people who responded are much more likely than the average recipient to be supportive of the organization’s position.
A
It draws a conclusion about a population from observations of a subgroup that is quite likely to be unrepresentative of that population in certain relevant respects.
The conclusion is based on responses of survey responders. It’s reasonable to think that responders are more likely to agree with the organization’s position than people who didn’t respond. So they’re likely unrepresentative of the entire group of 5,000.
B
It takes for granted that most individuals do not vary significantly in the opinions they would express on a given issue if surveyed regarding that issue on different occasions.
The conclusion asserts that most of the 5,000 agreed with the organization’s position. This doesn’t mean the author thinks people might not change their opinions later and respond differently later.
C
It relies on the accuracy of a survey made under conditions in which it is probable that most of the responses to that survey did not correctly reflect the opinions of the respondents.
We have no reason to suspect that when people responded that they agreed with the organization, that they actually didn’t agree. It’s possible this happened, but we have no reason to think it’s “probable.”
D
It uses evidence about an opinion held by the majority of a population in an attempt to justify a conclusion regarding the opinion of a small part of that population.
(D) is reversed. The author uses evidence concerning a small portion of a population (the survey responders) to justify a conclusion about a majority of the population (most people who got the letter and survey).
E
It takes for granted that the fund-raising letter had some influence on the opinions of most of the people who received it.
The author doesn’t assume that the letter affected anyone’s opinions. The argument simply interprets the survey results as indicative of the opinion of most people who got the letter.
Summarize Argument
The author concludes that the revolutionary party was not overambitious and caused NO suffering. This is based on the fact that most of the party’s goals were achieved quickly and that the party didn’t have enough power to cause GREAT suffering.
Identify and Describe Flaw
There are two key assumptions. First, the author assumes that achieving most goals quickly implies that there weren’t many overambitious goals. This overlooks the possibility that there were a lot of goals that the party still didn’t achieve. Second, the author assumes that not being able to cause GREAT suffering implies that the party caused NO suffering. This overlooks the possibility that the party still caused some suffering, even if it wasn’t great.
A
gives mutually inconsistent responses to the two criticisms
There’s nothing contradictory about claiming that the party achieved most goals and that it didn’t have enough power to cause great suffering. Both can be true.
B
fails to establish that the revolutionary party caused no suffering
The author’s premises establish that the party didn’t cause GREAT suffering. But this doesn’t establish what the conclusion asserts — that the party caused NO suffering.
C
fails to establish that any of the revolutionary party’s critics underestimated the party’s power
The argument didn’t need to establish anything about the critics of the revolutionary party. The critics’ claims are mentioned purely as context in the first sentence; the argument’s reasoning doesn’t rely on critics’ perceptions of the party.
D
provides no evidence that the revolutionary party’s goals were not overambitious
The author does provide some evidence that the goals were not overambitious — the party achievedmost of its goals quickly. This evidence doesn’t prove that the party was not overambitious, but it does constitute at least some evidence it wasn’t ambitious.
E
fails to consider other major criticisms of the revolutionary party
The argument didn’t need to consider other major criticisms. It focusd on two particular criticisms about being overambitious and causing great suffering and tried to rebut those points. But the argument doesn’t take a position on any other issues.