To begin with, the article’s author provides no evidence that the study’s two groups were
otherwise at similar risk of stroke. Lacking such evidence, it is entirely possible that the
difference in stroke risk is attributable to some other phenomenon. Perhaps the average age of
the tea drinkers was significantly lower than that of the other group. Assuming that stroke risk
generally increases with age, this scenario would provide an equally plausible explanation for
the difference in stoke risk between the two groups. Or, perhaps the tea-drinkers tended to
engage in other activities that reduced their stroke risk, or to avoid activities that increased that
risk, whereas the other group did not.
Even assuming that Elysian men do indeed reduce stroke risk by drinking three cups of
black tea each day, it is nevertheless unfair to infer that women and non-Elysians would
benefit similarly from drinking black tea. Perhaps women do not derive this same benefit from
black-tea consumption; for that matter, perhaps for women the author’s prescrip tion would
actually increase stroke risk. Also, perhaps Elysians have certain other habits or certain
inherited traits needed for a person to reduce his or her stroke risk by drinking black tea
habits or traits which are far less common among non-Elysians.
Even if any person would reduce his or her risk of stroke by drinking at least three cups of
black tea each day, the author overlooks the possibility that stroke risk can just as effectively
be reduced by other means as well. Some other type of tea or herb might be just as beneficial
in this respect, or perhaps even more so. Or, people who weigh less than the men in the study
might derive the maximum benefit from black tea by drinking less than three cups per day. For
that matter, perhaps drinking 3 cups or more would amount to a harmful overdose for these
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people. Without accounting for these possibilities the author’s recommendation seems
premature at best.
Finally, even if all adult men and women would reduce their stroke risk by following the
author’s prescribed regimen for up to a ten-year period, it is possible that following this
regimen for a longer period would actually harm one’s health. Without the benefit of a longer
study---one in which subjects consume black tea daily from an early age up until an age at
which strokes are likely in any event, the author simply cannot justify the advice that
health-conscious people adhere to the prescribed regimen from an early age.
In sum, the argument is weak as it stands. To strengthen it the author must provide evidence
that the study’s two groups were similar in all other ways that might possibly affect their risk of
stroke, and that it was the tea itself rather than some other habit--that caused the
comparatively low risk of stroke among the tea-drinking group. The author must also show that
women and non-Elysians benefit similarly from the prescribed amount of black tea. To better
assess the argument it would be useful to know what alternatives are available for reducing
stroke risk, whether the benefits of drinking black tea vary with age or body weight, and the
potential longer-term health hazards of consuming black tea on a daily basis.
Argument 28
The following appeared in a report of the Committee on Faculty Promotions and Salaries at
Elm City University."During her seventeen years as a professor of botany, Professor Thomas has proved herself to
be well worth her annual salary of $50,000. Her classes are among the largest at the university,
demonstrating her popularity among students. Moreover, the money she has brought to the
university in research grants has exceeded her salary in each of the last two years. Therefore,
in consideration of Professor Thomas’ demonstrated teaching and research abilities, we
recommend that she receive a $10,000 raise and a promotion to Department Chairperson;
without such a raise and promotion, we fear that Professor Thomas will leave Elm City
University for another college."
In this report an Elm City University committee recommends increasing Professor Thomas’
salary and promoting her to Department Chairperson because of her effectiveness as a
teacher and researcher. To support this recommendation the report points out that Thomas’
classes are among the University’s most popular and that last year the amount of grant money
she attracted to the University exceeded her $50,000 salary. The committee argues further
that unless the University implements its recommendation Thomas is likely to defect to another
school. For several reasons, the evidence offered in support of the recommendation provides
little credible support for it.
First, the recommendation relies on the assumption that the popularity of Thomas’ classes is
attributable to her effectiveness as a teacher. Yet this assumption overlooks other possible
reasons for the popularity of these classes. Perhaps Thomas is a comparatively lenient grader;
or perhaps the classes she teaches are requirements for every science student. Without
considering and eliminating these and other possible alternative explanations for the popularity
of Thomas’ classes, the committee cannot convincingly condude based on that popularity that
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Thomas is an effective teacher and therefore should be granted a raise and a promotion.
Secondly, the mere fact that the amount of grant money Thomas attracted to the University
last year exceeded her salary proves nothing about either her teaching abilities or her research
abilities. Perhaps last year was an aberration, and in other years Thomas did not attract much
grant money. For that matter, perhaps many--or even most--other professors at the University
attracted even more grant money than Thomas, relative to their salary levels. Under either
scenario, Thomas would appear undeserving of the recommended raise and promotion
based on this particular criterion.
Thirdly, the report provides no evidence whatsoever regarding the likelihood that Thomas
would leave the University if she is not granted the proposed raise and promotion. Lacking
such evidence, it is entirely possible that Thomas is quite content in her current position and at
her current salary level. Thus the committee cannot justifiably rely on this daim to bolster its
recommendation.In conclusion, the committee’s recommendation is ill-founded. To strengthen it the
committee must provide dear evidence that Thomas is in fact an effective teacher--perhaps by
citing student or peer evaluations. The committee must also provide specific evidence of
Thomas’ research abilities--perhaps by listing scientific journals that have published the results
of her work. Finally, to better evaluate the argument I would need more information about the
degree to which Thomas is content in her current position and at her current salary, and
whether any other University would be willing to offer her a more attractive employment
package.
Argument 29
The following appeared in a newsletter distributed at a recent political rally.
"Over the past year, the Consolidated Copper Company (CCC) has purchased over one
million square miles of land in the tropical nation of West Fredonia. Mining copper on this land
will inevitably result in pollution and environmental disaster, since West Fredonia is home to
several endangered animal species. But such disaster can be prevented if consumers simply
refuse to purchase products that are made with CCC’s copper until the company abandons its
mining plans."
The author of this newsletter excerpt condudes that if consumers refuse to buy products
made with Consolidated Copper Company (CCC) copper the company will eventually abandon
its mining plans in the nation of West Fredonia, thereby preventing pollution and an
"environmental disaster" in that country. To justify this conclusion the author points out that
CCC has recently bought more than a million square miles of land in West Fredonia, and that
West Fredonia is home to several endangered animal species. I find this argument specious
on several grounds.
First, the author provides no evidence that the West Fredonia land that CCC has acquired
amounts to a significant portion of land inhabited by endangered animal species, or that CCC’s
land is inhabited by endangered animal species at all. Nor does the author provide clear
evidence that CCC’s mining activities are of the type that might cause pollution, the extinction
of animal species, or any other environmental damage. Lacking such evidence the author