Section Types Logical Reasoning

Student: The publications of Professor Vallejo on the origins of glassblowing have reopened the debate among historians over whether glassblowing originated in Egypt or elsewhere. If Professor Vallejo is correct, there is insufficient evidence for claiming, as most historians have done for many years, that glassblowing began in Egypt. So, despite the fact that the traditional view is still maintained by the majority of historians, if Professor Vallejo is correct, we must conclude that glassblowing originated elsewhere.

A

It draws a conclusion that conflicts with the majority opinion of experts.

There is nothing flawed about disagreeing with experts. What matters is whether you have enough evidence to support your conclusion. Whether that conclusion goes against experts’ views has no bearing on the quality of the argument.

B

It presupposes the truth of Professor Vallejo’s claims.

By using “if Professor V is correct,” the conclusion is conditioned on the hypothetical situation in which Professor V is correct. This does not assume that the professor is in fact correct. So the author doesn’t assume that Professor V’s claims are true.

C

It fails to provide criteria for determining adequate historical evidence.

The premise asserts that if Professor V is correct, there’s not enough evidence to say that glassblowing began in Egypt. We accept this premise as true. It doesn’t matter whether we know the criteria for adequate evidence.

D

It mistakes the majority view for the traditional view.

The author labels the view of “most historians” as the “traditional view.” We have no reason to think this labeling is wrong. In any case, whether a view is traditional has no impact on the argument. The author never rejected a view because it was traditional or not traditional.

E

It confuses inadequate evidence for truth with evidence for falsity.

The author confuses inadequate evidence for the truth of a claim (that glassblowing began in Egypt) as evidence that the claim is false. This is a flaw because a claim can still be true, even if there’s not enough evidence to prove that it’s true.

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LSAT 125 - Section 2 - Question 23

April 21, 2012

8 comments

LSAT 125 - Section 2 - Question 24

April 21, 2012

Cookie Cutter: PrepTest 23 Section 3 Question 10

There are 1.3 billion cows worldwide, and this population is growing to keep pace with the demand for meat and milk. These cows produce trillions of liters of methane gas yearly, and this methane contributes to global warming. The majority of the world’s cows are given relatively low-quality diets even though cows produce less methane when they receive better-quality diets. Therefore, methane production from cows could be kept in check if cows were given better-quality diets.

Summarize Argument

The amount of methane released because of cows would be reduced if they had better diets. This is because good diets make them produce less methane.

Notable Assumptions

The author assumes that giving cows healthier diets doesn’t have an undesirable consequence, such as causing them to produce less meat or milk. This may make it necessary to have more cows to compensate for decreased production per cow, thus potentially increasing methane production.

A

Cows given good-quality diets produce much more meat and milk than they would produce otherwise.

This strengthens the argument by reinforcing the assumption that feeding cows better diets would not limit their production of meat or milk. (A) says cows would produce less methane but even more milk and meat.

B

Carbon and hydrogen, the elements that make up methane, are found in abundance in the components of all types of cow feed.

This does not affect the argument. Cow feed having carbon and hydrogen doesn’t mean anything for our argument, as we know that healthier feed makes them produce less methane.

C

Most farmers would be willing to give their cows high-quality feed if the cost of that feed were lower.

This does not affect the argument. The conclusion is not about whether farmers should or could give their cows healthier diets. The conclusion is about what would happen if they did.

D

Worldwide, more methane is produced by cows raised for meat production than by those raised for milk production.

This does not affect the argument. The conclusion is still valid—regardless of which cows produce more methane, all cows’ methane production would decrease if given healthy diets.

E

Per liter, methane contributes more to global warming than does carbon dioxide, a gas that is thought to be the most significant contributor to global warming.

This does not affect the argument, which is solely about methane. The conclusion that methane production would decrease is not impacted by whether methane or carbon dioxide contributes more to global warming.

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LSAT 125 - Section 2 - Question 25

April 21, 2012

To face danger solely because doing so affords one a certain pleasure does not constitute courage. Real courage is manifested only when a person, in acting to attain a goal, perseveres in the face of fear prompted by one or more dangers involved.

Summary

Real courage requires persevering in the face of fear while acting to attain a goal.

Facing danger only because it brings one pleasure is not real courage.

Very Strongly Supported Conclusions

If one faces danger in order to attain a goal, he is only being courageous if he is also persevering in the face of fear.

If one perseveres in the face of fear, he is only being courageous if he’s also acting to attain a goal.

A

A person who must face danger in order to avoid future pain cannot properly be called courageous for doing so.

Unsupported. A person facing danger to avoid pain is acting to attain a goal. This person might also be persevering in the face of fear, in which case, they could potentially be called courageous.

B

A person who experiences fear of some aspects of a dangerous situation cannot be said to act courageously in that situation.

Unsupported. Courage requires persevering in the face of fear. The fact that someone experiences fear in a dangerous situation is not sufficient to conclude that they are not acting courageously.

C

A person who happens to derive pleasure from some dangerous activities is not a courageous person.

Unsupported. Facing danger solely because it brings pleasure is not real courage. As long as pleasure isn’t the only reason that this person faces danger, we can’t conclude that they are not courageous.

D

A person who faces danger in order to benefit others is acting courageously only if the person is afraid of the danger.

Very strongly supported. Courage requires persevering in the face of fear. One can only persevere in the face of fear if one is actually afraid. So someone who faces danger in order to attain the goal of benefiting others is only courageous if they are afraid of the danger.

E

A person who has no fear of the situations that everyone else would fear cannot be said to be courageous in any situation.

Unsupported. Just because this person isn’t afraid of the situations that other people are afraid of doesn’t mean that they aren’t afraid of any situation. This person might still persevere in the face of fear in some situations that other people do not fear.

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