Finally, the argument suffers from "either-or" reasoning. Based on the fact that Monroetown
residents are opposed to Brown’s proposed tax cut, the author unfairly concludes that they
must be in favor of Greene’s proposal. However, the author overlooks the possibility that
Monroetown residents are not in favor of either proposal.
In sum, the author’s argument that Monroetown residents oppose Brown’s proposal and are
in favor of the proposals set forth by Greene is unconvincing. To strengthen the argument the
author must provide clear evidence that Monroetown residents voted contrary to their own
positions on the issues when they reelected Brown. To better evaluate the argument I would
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need to know how much time passed between the collection of the statistics showing the
national tendency cited by the author and the election. I would also need to know how much
time passed between the election and the survey showing that Monroetown residents oppose
Brown’s proposal. Finally, I would need to know what portion of Monroetown’s residents voted
in the election, and what portion of these residents were shown by the survey to oppose
Brown’s policies.
Argument 37
The following is a memorandum from the director of personnel to the president of Get-Away
Airlines.
"Since our mechanics are responsible for inspecting and maintaining our aircraft, Get-Away
Airlines should pay to send them to the Quality-Care Seminar, a two-week seminar on proper
maintenance procedures. I recommend this seminar because it is likely to be a wise
investment, given that the automobile racing industry recently reported that the performance of
its maintenance crews improved markedly after their crews had attended the seminar. These
maintenance crews perform many of the same functions as do our mechanics, including
refueling and repairing engines. The money we spend on sending our staff to the seminar will
inevitably lead to improved maintenance and thus to greater customer satisfaction along with
greater profits for our airline."In this memorandum Get-Away Airline’s personnel director asserts that Get-Away
mechanics should enroll in the Quality Care Seminar on proper maintenance procedures in
order to increase customer satisfaction and, in turn, profits. The director reasons that because
the performance of auto-racing mechanics improves after the seminar, so will that of
Get-Away’s mechanics. The director’s argument relies on a number of dubious assumptions
and is therefore unconvincing.
First of all, the argument unfairly assumes that because the performance of auto-racing
mechanics improves after the seminar so will the performance of aircraft mechanics. Common
sense tells me that, even though aircraft and auto mechanics serve similar functions, aircraft
repair and maintenance is far more involved than car repair and maintenance. Thus, a seminar
that improves the performance of auto mechanics will not necessarily improve that of aircraft
mechanics.
Secondly, the argument assumes that the performance of Get-Away mechanics is subject to
improvement. However, it is entirely possible that their performance level is already very high
and that the seminar will afford little or no improvement. Perhaps Get-Away’s mechanics have
already attended a similar seminar, or perhaps they meet higher standards than the ones
imposed on auto-racing mechanics.
Thirdly, the argument concludes from the mere fact that the performance of auto-racing
mechanics improved after the seminar that the seminar was responsible for this improvement.
However, it is possible that some other factor, such as improved diagnostic technology or more
stringent inspection requirements, was the reason for the improved performance. Without
ruling out these and other such possibilities, I cannot accept the memo’s final conclusion that
enrolling in the seminar will improve the performance of Get-Away’s mechanics as well.
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Finally, the argument concludes without adequate evidence that improved performance on
the part of Get-Away’s mechanics will result in greater customer satisfaction and therefore
greater profits for Get-Away. Admittedly, if a low performance level results in accidents,
customer satisfaction and profits will in all probability decrease. Otherwise, however, improved
mechanic performance will in all likelihood have no bearing on customer satisfaction; in other
words, customers are unlikely to be aware of the level of performance of an aircraft’s
mechanics unless accidents occur.
In conclusion, the argtunent is unconvincing as it stands. To strengthen it, the director must
provide more convincing evidence that the performance of Get-Away’s mechanics will actually
improve as a result of the seminar--perhaps by pointing out other airlines whose mechanics
benefited from the seminar. The director must also show a strong causal nexus between
improved mechanic performance and profit. In order to better evaluate the argument, I would
need more information about the cost of the seminar compared to its expected benefits, and
about what factors other than the seminar might have been responsible for the improved
performance of auto-racing mechanics.Argument 38
The following is a letter to the editor of an environmental magazine.
"The decline in the numbers of amphibians worldwide clearly indicates the global pollution of
water and air. Two studies of amphibians in Yosemite National Park in California confirm my
conclusion. In 1915 there were seven species of amphibians in the park, and there were
abundant numbers of each species. However, in 1992 there were only four species of
amphibians observed in the park, and the numbers of each species were drastically reduced.
The decline in Yosemite has been blamed on the introduction of trout into the park’s waters,
which began in 1920 (trout are known to eat amphibian eggs). But the introduction of trout
cannot be the real reason for the Yosemite decline because it does not explain the worldwide
decline."
The author of this letter concludes that a worldwide decline in the number of amphibians is
an indication, or result, of global air and water pollution. To support this assertion the author
first notes a decline in amphibians in Yosemite Park between 1915 and 1992, and
acknowledges that trout, which eat amphibian eggs, were introduced there in 1925. But, the
author then claims that the introduction of trout cannot be the reason for the decline in
Yosemite because the introduction of trout in Yosemite does not explain the worldwide decline.
I find this argument logically unconvincing in three critical respects.
First, the author fails to provide any evidence to refute the strong inference that the
amphibian decline in Yosemite was indeed caused by trout. Because the author provides no
affirmative evidence that pollution---or some other phenomenon--was instead the reason for
the decline, the author’s broad assertion that a worldwide decline in amphibians indicates
global pollution is entirely unconvincing.
Secondly, even if I were to concede that the introduction of trout was not the cause of
Yosemite’s amphibian decline, the author provides no evidence that the decline was caused by
pollution--rather than some other phenomenon. Perhaps some other environmental factor was
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instead the cause. Without ruling out all other possible explanations the author cannot
convince me that pollution is the cause of the worldwide amphibian decline--or even the
decline in Yosemite alone.