Consumer advocate: In some countries, certain produce is routinely irradiated with gamma rays in order to extend shelf life. There are, however, good reasons to avoid irradiated foods. First, they are exposed to the radioactive substances that produce the gamma rays. Second, irradiation can reduce the vitamin content of fresh foods, leaving behind harmful chemical residues. Third, irradiation spawns unique radiolytic products that cause serious health problems, including cancer.

Summarize Argument

The consumer advocate concludes that irradiated foods should be avoided, based on three points: (1) irradiated foods are exposed to radioactive substances, (2) irradiation can reduce vitamins and leave harmful chemical residues, and (3) irradiation creates unique radiolytic products that may cause serious health issues, including cancer.

Notable Assumptions

The consumer advocate makes the following assumptions:

Irradiating foods causes unique radiolytic products to be in the produce itself.

Just because irradiation can reduce vitamins in produce, it does reduce vitamins in produce.

The amount of harmful chemical residue left after irradiation is more than the amount left without it.

Because irradiation creates unique radiolytic products and these products cause cancer, irradiated foods cause cancer.

A
Unique radiolytic products have seldom been found in any irradiated food.

The consumer advocate assumes that irradiation, which creates unique radiolytic products, causes those unique radiolytic products to be present in the produce itself. (A) weakens the argument by showing that this assumption is false.

B
Cancer and other serious health problems have many causes that are unrelated to radioactive substances and gamma rays.

This doesn't weaken the argument. The fact that cancer and other health problems have other causes doesn't mean that radioactive substances and gamma rays don't also cause these issues and need to be avoided.

C
A study showed that irradiation leaves the vitamin content of virtually all fruits and vegetables unchanged.

The consumer advocate assumes that, just because irradiation can reduce the vitamins in produce, it actually does reduce the vitamins in produce. (C) weakens the argument by showing that this assumption is false.

D
The amount of harmful chemicals found in irradiated foods is less than the amount that occurs naturally in most kinds of foods.

The consumer advocate assumes that the amount of harmful chemical residues left after irradiation is more than the amount of harmful chemical residues left without irradiation. (D) weakens the argument by showing that this assumption is false.

E
A study showed that the cancer rate is no higher among people who eat irradiated food than among those who do not.

The consumer advocate assumes that, because irradiation creates unique radiolytic products and these products cause cancer, irradiated foods cause cancer. (E) undermines this link by showing that cancer rates are not actually higher among people who eat irradiated food.


10 comments

Philosopher: To explain the causes of cultural phenomena, a social scientist needs data about several societies: one cannot be sure, for example, that a given political structure is brought about only by certain ecological or climatic factors unless one knows that there are no similarly structured societies not subject to those factors, and no societies that, though subject to those factors, are not so structured.

Summarize Argument: Causal Explanation
To be able to explain the causes of cultural phenomena, you can’t just look at one society in isolation; you need data about several societies. Why? The philosopher walks us through an example. Say you want to know whether a certain political system can only be caused by specific environmental conditions. You’d need to know that this political system and these environmental conditions always go hand-in-hand. So, you’d need to look at the political systems and environmental conditions of several different societies to be sure there’s a pattern.

Identify Argument Part
The claim referenced in the question stem is the first sentence in the stimulus. It’s the philosopher’s main conclusion, and is supported by an example.

A
It describes a problem that the philosopher claims is caused by the social scientist’s need for certainty.
The referenced text is a conclusion, not a problem. The philosopher is stating what social scientists must do rather than describing issues within the field.
B
It is a premise used to support a general theoretical claim about the nature of cause and effect relationships.
The referenced text is a conclusion supported by the rest of the argument. There’s no general claim about the nature of cause and effect relationships.
C
It is a general hypothesis that is illustrated with an example showing that there is a causal relationship between political structures and environmental conditions.
“Hypothesis” is appealing, and there’s certainly an example. However, the example doesn’t demonstrate a causal relationship between political structures and environmental conditions. It simply states a conditions needed to be certain that such a relationship exists.
D
It is a dilemma that, it is argued, is faced by every social scientist because of the difficulty of determining whether a given cultural phenomenon is the cause or the effect of a given factor.
The philosopher doesn’t claim the referenced text is a dilemma, nor that it’s difficult to determine cause and effect. The philosopher simply claims that social scientists must examine several societies to explain the causes of cultural phenomena.
E
It is a claim that the philosopher attempts to justify by appeal to the requirements for establishing the existence of one kind of causal relationship.
The claim in question is the conclusion about social scientists’ need to examine other cultures. The justification is the example about ecological causes of political systems, which is one kind of causal relationships. This works!

34 comments

Scientist: Physicists claim that their system of careful peer review prevents scientific fraud in physics effectively. But biologists claimed the same thing for their field 20 years ago, and they turned out to be wrong. Since then, biologists have greatly enhanced their discipline’s safeguards against scientific fraud, thus preventing further major incidents. It would be conducive to progress in physics if physicists were to do the same thing.

Summarize Argument
The author concludes that if physicists were to greatly enhance their discipline’s safeguards against scientific fraud, progress in physics would be advanced. This is based on an analogy to what occurred in the field of biology. Biologists enhanced their discipline’s safeguards against scientific fraud, and this prevented major incidents of fraud.

Notable Assumptions
The author assumes that preventing major incidents of fraud is something that would help advance progress in physics. The author also assumes that what happened in biology after biologists enhanced safeguards is likely to happen in physics after physicists enhance safeguards.

A
Major incidents of scientific fraud in a scientific discipline are deleterious to progress in that discipline.
This strengthens the link between preventing major incidents of fraud and advancing progress in a scientific discipline. Without (A), the argument contains no premise that allows us to conclude that anything is “conducive to progress in physics.”
B
Very few incidents of even minor scientific fraud have occurred in biology over the last 20 years.
The premises already establish that “further major incidents” of fraud were prevented in biology after the enhanced safeguards. What’s missing is how this relates to scientific progress in the field.
C
No system of careful peer review is completely effective in preventing scientific fraud in any scientific discipline.
The physicists never claimed that their peer review system was “completely” effective. We want to establish that improving physics’ safeguards will help advance progress in physics. Showing that the current peer review system isn’t perfect doesn’t help us reach this conclusion.
D
Twenty years ago the system of peer review in biology was less effective in preventing scientific fraud than the system of peer review in physics is today.
If anything, this might weaken by pointing out a relevant difference between biology and physics that could suggest what happened in biology after safeguards were established wouldn’t necessarily happen to physics.
E
Over the years, there have been relatively few, if any, major incidents of scientific fraud in physics.
If anything, this might weaken by suggesting that stronger safeguards in physics wouldn’t necessarily have a meaningful impact on major incidents of fraud, since there are already so few.

45 comments

Lutsina: Because futuristic science fiction does not need to represent current social realities, its writers can envisage radically new social arrangements. Thus it has the potential to be a richer source of social criticism than is conventional fiction.

Priscilla: That futuristic science fiction writers more skillfully envisage radically new technologies than new social arrangements shows how writers’ imaginations are constrained by current realities. Because of this limitation, the most effective social criticism results from faithfully presenting the current social realities for critical examination, as happens in conventional fiction.

Speaker 1 Summary
Lutsina concludes that futuristic sci-fi has the potential to be a richer source of social criticism than conventional fiction. This is because futuristic sci-fi writers can write about new social arrangements, since they don’t have to represent current social realities.

Speaker 2 Summary
Priscilla concludes that the most effective social criticism results from accurately presenting current social realities, as conventional fiction does. This view is based on the claim that futuristic sci-fi writers are better at imagining new technologies than they are at imagining new social realities. This shows that writers’ imaginations are constrained by current realities.

Objective
We’re looking for a point of disagreement. The speakers disagree about whether sci-fi or conventional fiction are the best at social criticism.

A
some science fiction writers have succeeded in envisaging convincing, radically new social arrangements
Neither expresses an opinion. Lutsina only speaks about potential effectiveness, not about actual successes in writing social criticism. Priscilla doesn’t say anything about successful sci-fi writers.
B
writers of conventional fiction are more skillful than are writers of futuristic science fiction
Neither expresses an opinion. Lutsina doesn’t discuss skill. Priscilla refers to skill at imagining technology and social arrangements, but doesn’t refer to writing skill. Neither compares writing skill among sci-fi and conventional writers.
C
futuristic science fiction has more promise as a source of social criticism than does conventional fiction
This is a point of disagreement. Lutsina thinks sci-fi does hold more promise. Priscilla thinks the most effective social criticism happens in conventional fiction (and therefore not in sci-fi).
D
envisaging radically new technologies rather than radically new social arrangements is a shortcoming of futuristic science fiction
Lutsina doesn’t express an opinion about this. She refers only to envisaging new social arrangements, but says nothing about new technologies.
E
criticism of current social arrangements is not effective when those arrangements are contrasted with radically different ones
Neither has an opinion. To Lutsina, imagining new arrangements can lead to better criticism, but that doesn’t mean anything is required to be effective. To Priscilla, current arrangements are important, but that doesn’t mean comparisons to other arrangements are required.

6 comments