Despite increasing international efforts to protect the natural habitats of endangered species of animals, the rate at which these species are becoming extinct continues to rise. It is clear that these efforts are wasted.

Summarize Argument
International efforts to protect the natural habitats of endangered species are wasted. This is because the rate of extinction for endangered species continues to grow.

Notable Assumptions
The author assumes that if the rate of extinction for endangered species rises, then international efforts to protect their habitats are entirely wasted. Furthermore, the author assumes that the rate of extinction for these animals would not be significantly higher without the international efforts to protect their natural habitats.

A
Scientists are better able to preserve the habitats of endangered species now than ever before.
This does not affect the argument. While scientists may be better able to protect endangered animals’ natural habitats, the rate of extinction for these animals is nevertheless increasing.
B
Species that would have become extinct have been saved due to the establishment of animal refuges.
This weakens the argument. It exploits the author’s assumption that if the rate of extinction for endangered species rises, all efforts are wasted. (B) says the efforts are not being wasted, as species are being saved from extinction.
C
Scientists estimate that at least 2000 species become extinct every year.
This does not affect the argument. While the increase in the rate at which endangered species are going extinct is a key part of the argument, the actual number of species that go extinct in a given year is not relevant.
D
Many countries do not recognize the increased economic benefit of tourism associated with preserved natural habitats.
This does not affect the argument. Countries failing to recognize other benefits of efforts to protect natural habitats does not weaken the conclusion that the protection efforts are wasted because the rate of extinction of endangered species continues to rise.
E
Programs have been proposed that will transfer endangered species out of habitats that are in danger of being destroyed.
This does not affect the argument. Proposed programs (i.e., programs that do not currently exist) are outside the scope of the argument.

37 comments

Aaron: A prominent judge, criticizing “famous lawyers who come before courts ill-prepared to argue their cases,” recently said, “This sort of cavalier attitude offends the court and can do nothing but harm to the client’s cause.” I find the judge’s remarks irresponsible.

Belinda: I find it natural and an admirable display of candor. Letting people know of the damage their negligence causes is responsible behavior.

Speaker 1 Summary
An important judge criticized famous lawyers who aren’t prepared to argue their cases in court. Aaron asserts that the judge’s comments were irresponsible.

Speaker 2 Summary
Belinda asserts that the judge was good to make that criticism. This is because letting the lawyers know about the damage caused by their lack of preparation is a responsible thing to do.

Objective
We’re looking for a point of disagreement. The speakers disagree about whether the judge’s criticism was responsible. Aaron believes it wasn’t. Belinda believes it was.

A
ill-prepared lawyers damage their clients’ causes
Aaron doesn’t express an opinion. He calls the judge’s remarks irresponsible, but that doesn’t mean he believes ill-prepared lawyers harm their clients. He might just think the judge shouldn’t have aired that criticism publicly.
B
the judge’s criticism of lawyers is irresponsible
This is a point of disagreement. Aaron thinks the judge’s remarks were irresponsible. Belinda thinks the judge engaged in responsible behavior by letting the lawyers know about the harm they cause.
C
a lawyer’s being ill-prepared to argue a client’s case constitutes negligence
Aaron doesn’t express an opinion. Although he thinks the judge’s remarks were irresponsible, that doesn’t imply he thinks ill-prepared lawyers are not negligent. He might agree that those lawyers are negligent, but think the judge was wrong to air criticism publicly.
D
famous lawyers have a greater responsibility to be well prepared than do lawyers who are not famous
Neither speaker expresses an opinion. They don’t discuss non-famous lawyers or what kind of lawyers has a greater responsibility to be prepared.
E
it is to be expected that ill-prepared lawyers would offend the court in which they appear
Neither speaker expresses an opinion. Although the speakers have opinions about whether the judge’s remarks were responsible, they don’t suggest anything about the concept of “offense” or who we would expect to cause offense to a court.

2 comments

Recent investigations of earthquakes have turned up a previously unknown type of seismic shock, known as a displacement pulse, which is believed to be present in all earthquakes. Alarmingly, high-rise buildings are especially vulnerable to displacement pulses, according to computer models. Yet examination of high-rises within cities damaged by recent powerful earthquakes indicates little significant damage to these structures.

"Surprising" Phenomenon
Why have high-rises within cities damaged by recent powerful earthquakes sustained little significant damage when computer models say these buildings are especially vulnerable to displacement pulses?

Objective
Any hypothesis that can resolve this will need to explain how these buildings manage to avoid significant damage during earthquakes, despite their expected vulnerability.

A
Displacement pulses travel longer distances than other types of seismic shock.
It doesn’t matter how far displacement pulses travel compared to other seismic shocks. We need to know why high-rises are able to withstand powerful displacement pulses.
B
Scientific predictions based on computer models often fail when tested in the field.
If scientific predictions based on computer models are frequently inaccurate, it’s possible the models’ predictions about high-rises may be inaccurate. Therefore, (B) presents the possibility that high-rises aren’t actually vulnerable to displacement pulses in the first place.
C
While displacement pulses have only recently been discovered, they have accompanied all earthquakes that have ever occurred.
This confirms that all earthquakes are accompanied by displacement pulses but does nothing to explain why high-rises have sustained little damage from these pulses.
D
The displacement pulses made by low- and medium-intensity earthquakes are much less powerful than those made by the strongest earthquakes.
We’re not concerned with low- and medium-intensity earthquakes or their displacement pulses. The stimulus only discusses powerful earthquakes and their displacement pulses.
E
Computer models have been very successful in predicting the effects of other types of seismic shock.
This fails to explain why high-rises suffer little significant damage. If anything, this deepens the mystery, because if computer models are so good at predicting the effects of other seismic shocks, then why are the models about the effects of displacement pulses on high-rises so at odds with real-world results?

30 comments

Terry: Months ago, I submitted a claim for my stolen bicycle to my insurance company. After hearing nothing for several weeks, I contacted the firm and found they had no record of my claim. Since then, I have resubmitted the claim twice and called the firm repeatedly, but I have yet to receive a settlement. Anyone can make mistakes, of course, but the persistence of the error makes me conclude that the company is deliberately avoiding paying up.

Summary

Terry submitted a claim for his stolen bicycle.

Weeks later, the insurance company had no record of the claim.

Terry then submitted the claim two more times, but has not received a settlement.

Anyone can make mistakes.

Because of the persistence of the error, Terry believes that the company is avoiding paying the settlement.

Notable Valid Inferences

Terry believes that the delay in paying the settlement is not an unintentional mistake by the insurance company.

A
Consumers should avoid attributing dishonesty to a corporation when the actions of the corporation might instead be explained by incompetence.

This must be false. Terry has attributed dishonesty to the corporation, even though the corporation’s actions could be explained by incompetence. Terry’s conclusion that the company is deliberately avoiding paying the settlement is a violation of this principle.

B
Consumers should attempt to keep themselves informed of corporate behavior that directly affects their interests.

This could be true. We just don’t have enough information to determine how much Terry has been keeping himself informed.

C
In judging the quality of service of a corporation, a consumer should rely primarily on the consumer’s own experience with the corporation.

This could be true. Terry is relying on his own experience to make his conclusion, so this principle has not been violated.

D
In judging the morality of a corporation’s behavior, as opposed to that of an individual, mitigating circumstances are irrelevant.

This could be true. Terry doesn’t seem to be considering mitigating circumstances, so the information given is consistent with the principle in (D).

E
Corporations ought to make available to a customer any information the customer requests that is relevant to the customer’s interests.

This could be true. The first time Terry reached out, the corporation answered that they had no record of his claim. In further communications, we only know that Terry hasn’t received his settlement; we don’t know if the corporation withheld information.


31 comments

The question stem reads: The editorialist's reasoning is flawed in that it fails to take into account that… This is a Flaw question.

The editorialist states that a recently passed law limits freedom of speech to silence dissenters. He then describes the claim that those ignorant of history are doomed to repeat it. In this claim, "doomed" is a necessary condition indicator. So we can rewrite the claim into lawgic: ignorant of history -> repeat history. The editorialist concludes that "If this (ignorant of history -> repeat history) is true, then those responsible for passing the laws must be ignorant of a great deal of history." In lawgic, the conclusion reads:

(ignorant of history -> repeat history) -> law passers ignorant of history

The editorialists note that in the past, silencing dissenters have tended to promote undemocratic policies and the establishment of authoritarian regimes. Let's outline the argument::

P1: A Law has been passed to silence dissenters

P2: Silencing dissenters has occurred in the past.

______________________________________________

C: (ignorant of history -> repeat history) -> law passers ignorant of history

Looking at the premises, we can infer that history has been repeated. Dissenters have been silenced in the past, and lawmakers today are trying to silence dissenters now.

P1: A Law has been passed to silence dissenters

P2: Silencing dissenters has occurred in the past.

P3: history has been repeated

______________________________________________

C: (ignorant of history -> repeat history) -> law passers ignorant of history

Finally, we can kick up the sufficient condition of the conclusion:

P1: A Law has been passed to silence dissenters

P2: Silencing dissenters has occurred in the past.

P3: history has been repeated

P4: ignorant of history -> repeat history

______________________________________________

C: law passers are ignorant of history

Remember, satisfying the necessary condition yields no information about the sufficient condition. The editorialist has used the fact that history has been repeated (P4's necessary condition) to conclude that the lawmakers are ignorant of history (P4's sufficient condition). The editorialist is affirming the consequent, a classic logical fallacy. Now that we see the error in the editorialist's reasoning let's move the answer choices.

Answer Choice (A) is irrelevant to the argument. The purpose of the law does not matter. What matters to the argument is that history is repeating itself.

Answer Choice (B) is irrelevant. If you picked (B), you likely got caught up in irrelevant parts of the stimulus, i.e., "limits freedom of speech" and "tended to promote undemocratic policies and the establishment of authoritarian regimes." But the editorialist's argument is not about what freedoms need or need not be protected.

Answer Choice (C) is actually taken into account by the argument. The stimulus says, "silencing dissenters has tended to promote… the establishment of authoritarian regimes." The fact that you can find some instances of undermining regimes is compatible with the editorialist's claim. Furthermore, what matters is that a law "silencing dissenters" is a repeat of history. Whether or not the law ends up establishing or undermining an authoritarian regime is arbitrary.

Answer Choice (D) is also irrelevant. Whether the law is good or bad has no effect on the argument.

Correct Answer Choice (E) is an illustration of our prephase. Those ignorant of history are doomed to repeat it, but it is entirely possible to be aware of history and still repeat it. Maybe these lawmakers intend to establish an authoritarian regime. Maybe not. In either case, (E) is good to go.


20 comments

This is an MBT question which we know because the question stem reads: If the statements above are true, then which one of the following must also be true?

Our stimulus gives us a set of facts about a plant called “false chicory”--which I can only assume is the sworn enemy of true chicory (kind of like the false chicory Wario to the true chicory’s Mario).

We know that false chicory (why is it false? Does it tell lies?) has a taproot that is half the size of the plant’s height. We also are told that false chicory tends to grow more as it receives more rain. We know that false chicory definitely reaches above average heights if it receives more than twice the average rainfall of its normal habitat.

Notice the shifting from tends to grow taller in sentence two, to always reaches above average heights in sentence three. One happens more often than not, the other always happens.

So what inferences can we make here? Well we know that the taproot is directly proportional to the height of a false chicory (it’s always half the value of the height). We also have some information about what causes the height of a false chicory plant to increase (namely, rain—more specifically twice than average normal rainfall). So can we make some conclusions about what might cause a taproot to grow? I think we can! Anything that makes the false chicory grow taller will also make its taproot grow longer (to exactly one half its height). Therefore rain that contributes to an increase in height would also contribute to a growth in the length of the taproot (that is exactly one half the value of its increase in height).

Cool? Cool!

Now let’s move on to the answer choices:

Answer Choice (A) This is tempting because it's playing on what we know about rain contributing to the height of a false chicory. But all we know about false chicory plants that receive more than twice the standard amount of rain is that they are always above average height. Does this mean that plants that don’t receive this much rain can’t be above average height? No! There may be all sorts of things that contribute to the growth of false chicory and rain is just one of them. There’s also the possibility that both of these plants with different heights received greater than average rainfall. This would mean that they both are above average height, but there would still most likely be a difference in height between them.

Answer Choice (B) So we know that if a false chicory plant has above average height, its taproot will be above average length (because it is always exactly one half of the plant’s height). But this AC has the same error that we found in (A). Receiving more than twice the amount of average rain is sufficient to cause above average height, but that doesn’t mean it’s the only thing that can cause it.

Answer Choice (C) Yet another answer choice that is demonstrating the same error we found in (A) and (B). More than twice the average rainfall is the sufficient condition and above average height is the necessary condition. This answer choice flips the two conditions.

Answer Choice (D) A few problems here. First, to reiterate: there are any number of factors that could contribute to the growth of false chicory. Just because these groups are the same height, does not mean that we can determine if they received the same amount of rainfall. Secondly, this question reads “[if] one group [is] not taller than [another] group,” then those groups must have received the same amount of rainfall. What does this mean? It means the first group could be the same size as the second group, or it could be any other size smaller than the second group. The chicory plants in the second group could all be 6 feet tall compared to the plants in the first group coming in at just over 6 inches tall—this would fit within the parameters set by our stimulus. So even if there was a direct correlation between rainfall and height (and no other factors involved in height), this would not be supported.

Correct Answer Choice (E) We know that if a false chicory plant receives greater than twice average rainfall it will be above average height. We also know that taproots are exactly half the size of the plant’s stalk (or whatever you call the vertical section of a false chicory plant–if you can’t tell by now, I am not a botanist!). Therefore, average taproot length would be exactly one half of average taproot height. So we can definitively say that if receiving more than twice the average amount of rainfall will lead to false chicory plants being above average height, it will also lead to them having taproots that are above average length.


6 comments