Summarize Argument: Counter-Position
The author considers the general principle that only highly evolved species alter the environment to aid their survival and concludes this characteristic is common. As evidence, the author provides an example of some species of plankton. Plankton generate a gas that is converted into particles of sulfate, which causes water vapor to condense and form clouds. More cloud cover causes more sunlight to be reflected so the Earth absorbs less heat. Therefore, these plankton cause the surface of the Earth to be cooler for their benefit.
Describe Method of Reasoning
The author counters a position held by others. She offers a counter example to illustrate that the general principle believed by others is incorrect. If some species of plankton are able to alter the environment for their benefit, then it cannot be true that only highly evolved species have this characteristic.
A
A general principle is used to justify a claim made about a particular case to which that principle has been shown to apply.
The author’s argument counters the general principle believed by others. The particular case of certain species of plankton counters this general principle.
B
An explanation of how a controversial phenomenon could have come about is given in order to support the claim that this phenomenon did in fact come about.
The author does not address any phenomenon that is controversial. We cannot assume that because certain species of plankton act contrary to what others believe that the behavior of these plankton is controversial.
C
A generalization about the conditions under which a certain process can occur is advanced on the basis of an examination of certain cases in which that process did occur.
The author’s argument counters the general principle believed by others. The general principle believed by others is not a generalization about conditions a certain process can occur. Rather, the generalization is about what kinds of species can alter their environment.
D
A counterexample to a position being challenged is presented in order to show that this position is incorrect.
The position being challenged is the general principle that only highly evolved species can alter their environment to aid their own survival. The counterexample the author provides to counter this position is the case of certain species of plankton.
E
A detailed example is used to illustrate the advantage of one strategy over another.
The author does not compare strategies. The author’s argument only presents one strategy that certain species of plankton use.
Smoker: But it is equally well established that regularly eating high-fat, high-cholesterol foods causes as many serious health problems as does smoking, yet it would be manifestly unreasonable to force those who purchase such foods to bear the burden of financing this campaign.
Summarize Argument: Counter-Position
In response to the politician’s claim that the new nationwide health-awareness campaign should be funded by increasing taxes on cigarettes, the smoker counters that regularly eating high-fat and high-cholesterol foods cause as many serious health problems as smoking. Moreover, the smoker states it would be unreasonable to force consumers of these foods to bear the burden of financing the campaign.
Describe Method of Reasoning
The smoker counters the position held by the politician. He does this by providing a counterexample. If consuming certain foods cause as many serious health problems as smoking, but it would be unreasonable for the consumers of these foods to bear the burden of financing the campaign, then it is likely equally unreasonable for smokers to bear the burden of financing the campaign.
A
offers a counterexample that calls into question the politician’s reasoning
The counterexample is the people who consume high-fat and high-cholesterol foods. The politician’s reasoning questionable because, if it is unreasonable to force these people to fund the campaign, then it is likely unreasonable to force smokers to fund the campaign.
B
presents an alternative solution to that proposed by the politician
The smoker does not propose any solution.
C
argues that the method proposed by the politician would be inadequate for its intended purpose
The smoker does not state that the politician’s proposal is inadequate. Rather, the smoker implies that the politician’s proposal is unfair because similarly situated groups would not bear the burden of financing the campaign.
D
questions the accuracy of the information cited by the politician in reaching a conclusion
The smoker does not question the politician’s premises. In fact, the smoker concedes that smoking causes as many serious health problems compared to ingesting high-fat and high-cholesterol foods.
E
illustrates how the politician’s proposal could aggravate the problem it is intended to solve
The smoker does not suggest that the politician’s proposal would cause people to smoke more cigarettes.
Keisha: Anarchists have always been few in number, whereas other ideologies have often spawned mass movements. Therefore, the proportion of anarchists who are violent is possibly greater than the proportion of adherents of other ideologies who are violent.
Summarize Argument: Counter-Position
In response to Tony’s claim that the association between anarchism and political violence is unwarranted, Keisha concludes that the proportion of violent anarchists is possibly greater in comparison to other ideologies. As evidence, she points out that anarchism has always had few members in comparison with other ideologies.
Describe Method of Reasoning
Keisha counters the position held by Tony. She does this by positioning the small number of violent anarchists in the context of the total population of anarchists. Even if violent anarchists are outnumbered by the violent adherents of other ideologies, the proportion of violent anarchists might be greater than the proportion of violent adherents of other ideologies.
A
She shows that Tony’s conclusion is questionable because Tony bases it on a comparison that inappropriately involves absolute numbers rather than proportions.
The comparison Tony makes is between the absolute number of violent anarchists compared to the absolute number of violent adherents of other ideologies. Keisha thinks Tony’s conclusion is questionable without acknowledging the proportion of violent members in each group.
B
She attempts to undermine Tony’s conclusion by introducing plausible evidence that is incompatible with the evidence Tony offers in support of that conclusion.
The evidence Keisha offers is not incompatible with Tony’s evidence. Rather, Keisha is pointing out that Tony’s conclusion is questionable without considering the factors she mentions.
C
She questions the accuracy of the claims on which Tony bases his conclusion.
Keisha does not question the accuracy of Tony’s claims. Rather, Keisha is pointing out that Tony’s premises do not necessarily support his conclusion because his argument only accounts for absolute numbers instead of proportions.
D
She presents evidence that the two groups Tony has compared have no significant qualities in common.
Keisha’s evidence does not suggest that she thinks the two groups Tony compares have no qualities in common. She acknowledges Tony’s comparison and questions it because Tony fails to consider proportions between groups.
E
She indicates that Tony has adopted questionable criteria for including certain people in the groups he is comparing.
Tony does not provide any criteria for determining who belongs to a certain group.