The question stem reads: The flawed pattern of reasoning in which one of the following is most closely parallel to that in the argument above? This is a Parallel Flaw question.

The author states," A species in which mutations frequently occur will develop new evolutionary adaptations in each generation." We can translate this into lawgic to read:

Mutations Frequently Occur -> Develop Evolutionary Adaptations

The author then states the premise and conclusion, "Since species survive dramatic environmental changes only if they develop new evolutionary adaptions (premise), a species in which mutations occur frequently occur will survive drastic environmental changes (conclusion)." Let's translate those into lawgic:

Premise:
Survive Dramatic Environmental Changes -> Develop Evolutionary Adaptations

Conclusion:
Mutations Frequently Occur -> Survive Dramatic Environmental Changes.

We can combine the argument to read:

P1: Mutations Frequently Occur -> Develop Evolutionary Adaptations
P2: Survive Dramatic Environmental Changes -> Develop Evolutionary Adaptations
____________________________________________________________________________
C: Mutations Frequently Occur -> Survive Dramatic Environmental Changes

We can see that the author confused the sufficient and necessary conditions of P2. Evolutionary adaptations are a requirement to survive dramatic environmental changes, but there might be additional requirements, such as having enough food. Let's take the general form of the argument:

A -> C
B -> C
____________
A -> B

By that line of reasoning, we could conclude that all apples (A) are peaches (B) because all apples (A) are fruit (C), and all peaches (B) are fruit (C).

When evaluating an answer choice, we need two sufficient conditions pointing to the same necessary condition. We also need a conclusion that says one of those sufficient conditions is sufficient for the other sufficient condition. Now that we know what we are looking for let's turn to the answer choices.

Answer Choice (A) is incorrect. The first premise says: properly built -> stones support each other. So the next premise needs "stones supporting each other" for the necessary condition. However, we get: sturdy -> properly built. So we can stop reading there.

Answer Choice (B) is incorrect. The first premise says: play before a different audience -> never get the same reaction. So the next premise needs to have "never get the same reaction" for the necessary condition. However, we get: play -> always has a different audience. Like (A), we can stop reading there.

Correct Answer Choice (C) is what we discussed. The first premise says: perfectly honest -> always tell the truth. So the next premise needs "always tell the truth" in the necessary condition. The next premise says: morally upright -> always tell the truth. Ok, so that checks out. The conclusion has to say: perfectly honest -> morally upright, which is exactly what (C) says. So (C) is the right answer.

Answer Choice (D) is incorrect. The first premise says: garden productive -> soil well drained. So the next premise needs "soil well drained" in the necessary condition. However, we get: soil well drained -> good soil. So we can eliminate (D).

Answer Choice (E) is incorrect. The forest premise says: diet healthful -> well balanced. So the next premise needs to have "well balanced" in the necessary condition. However, the next premise says: well-balanced -> includes fruit and vegetables. So we can eliminate (E).


9 comments

The question stem reads: The flawed pattern of reasoning in which one of the following is most closely parallel to that in the argument above? This is a Parallel Flaw question.

The author states," A species in which mutations frequently occur will develop new evolutionary adaptations in each generation." We can translate this into lawgic to read:

Mutations Frequently Occur -> Develop Evolutionary Adaptations

The author then states the premise and conclusion, "Since species survive dramatic environmental changes only if they develop new evolutionary adaptions (premise), a species in which mutations occur frequently occur will survive drastic environmental changes (conclusion)." Let's translate those into lawgic:

Premise:
Survive Dramatic Environmental Changes -> Develop Evolutionary Adaptations

Conclusion:
Mutations Frequently Occur -> Survive Dramatic Environmental Changes.

We can combine the argument to read:

P1: Mutations Frequently Occur -> Develop Evolutionary Adaptations
P2: Survive Dramatic Environmental Changes -> Develop Evolutionary Adaptations
____________________________________________________________________________
C: Mutations Frequently Occur -> Survive Dramatic Environmental Changes

We can see that the author confused the sufficient and necessary conditions of P2. Evolutionary adaptations are a requirement to survive dramatic environmental changes, but there might be additional requirements, such as having enough food. Let's take the general form of the argument:

A -> C
B -> C
____________
A -> B

By that line of reasoning, we could conclude that all apples (A) are peaches (B) because all apples (A) are fruit (C), and all peaches (B) are fruit (C).

When evaluating an answer choice, we need two sufficient conditions pointing to the same necessary condition. We also need a conclusion that says one of those sufficient conditions is sufficient for the other sufficient condition. Now that we know what we are looking for let's turn to the answer choices.

Answer Choice (A) is incorrect. The first premise says: properly built -> stones support each other. So the next premise needs "stones supporting each other" for the necessary condition. However, we get: sturdy -> properly built. So we can stop reading there.

Answer Choice (B) is incorrect. The first premise says: play before a different audience -> never get the same reaction. So the next premise needs to have "never get the same reaction" for the necessary condition. However, we get: play -> always has a different audience. Like (A), we can stop reading there.

Correct Answer Choice (C) is what we discussed. The first premise says: perfectly honest -> always tell the truth. So the next premise needs "always tell the truth" in the necessary condition. The next premise says: morally upright -> always tell the truth. Ok, so that checks out. The conclusion has to say: perfectly honest -> morally upright, which is exactly what (C) says. So (C) is the right answer.

Answer Choice (D) is incorrect. The first premise says: garden productive -> soil well drained. So the next premise needs "soil well drained" in the necessary condition. However, we get: soil well drained -> good soil. So we can eliminate (D).

Answer Choice (E) is incorrect. The forest premise says: diet healthful -> well balanced. So the next premise needs to have "well balanced" in the necessary condition. However, the next premise says: well-balanced -> includes fruit and vegetables. So we can eliminate (E).


9 comments

To predict that a device will be invented, one must develop a conception of the device that includes some details at least about how it will function and the consequences of its use. But clearly, then, the notion of predicting an invention is self-contradictory, for inventing means developing a detailed conception, and one cannot predict what has already taken place.

Summarize Argument
Predicting an invention is self-contradictory. Why? Because predicting an invention entails developing a detailed conception of how that invention will function. But if you manage to do that, congrats, you just invented the thing. So that’s not prediction. That’s just invention. Hence, predicting an invention is impossible.

Describe Method of Reasoning
Author argues that something (predicting an invention) is impossible because a necessary condition of that something (developing a detailed conception of how that invention will function) rules that something out by definition (you can’t predict an invention that already exists).

A
constructing a counterexample to a general hypothesis about the future
Descriptively inaccurate. Author does not construct a counterexample. There is no general hypothesis about the future to disprove.
B
appealing to definitions to infer the impossibility of a kind of occurrence
Descriptively accurate. The author implicitly appeals to the definition of “predict” (stating that something will happen) and explicitly appeals to the definition of “invent” (developing a detailed conception) to infer that a kind of occurrence (predicting an invention) is impossible.
C
countering a hypothesis by indicating the falsehood of the implications of that hypothesis
Descriptively inaccurate. We’ll grant that the “hypothesis” is that “it’s possible to predict an invention.” But the author does not demonstrate that the implications of that hypothesis are false. Rather, the author demonstrates that the hypothesis is self-contradictory.
D
pointing out how a problem is widely thought to be scientific yet is really conceptual
Descriptively inaccurate. Argument does not contain any problem that is “widely thought to be scientific” nor does the author point out any problem as being actually “conceptual.”
E
attempting to show that predicting any event implies that it has in fact already taken place
Descriptively inaccurate. Author does not attempt to show that predicting any event implies that it has in fact already taken place. That would mean prediction in general would be impossible. Author only attempts to show that predicting a specific type of event (inventions) would be impossible.

18 comments

This year a flood devastated a small river town. Hollyville, also a river town, responded with an outpouring of aid in which a majority of its residents participated, a proportion that far surpassed that of a few years ago when Hollyville sent aid to victims of a highly publicized earthquake. This year’s circumstances were a reversal of last year’s, when Hollyville itself was the scene of a deadly tornado and so the recipient rather than the supplier of emergency aid.

Summary
A few years ago, some Hollyville residents helped send aid to victims of an earthquake. Last year, Hollyville was hit by a tornado and received aid from others. This year, after a flood hit a different town, most Hollyville residents sent aid to that town. The proportion of Hollyville residents who sent aid this year was much higher than the proportion that sent aid a few years ago, before Hollyville itself had been hit by a natural disaster.

Strongly Supported Conclusions
Hollyville’s receipt of aid after a tornado may have increased the proportion of Hollyville residents willing to donate to others after a natural disaster.

A
People are more likely to aid people they know than they are to aid strangers.
Unsupported. We don’t know whether any of the recipients of aid were known or strangers to the people who gave the aid. So there’s no evidence that people are more likely to aid people they know.
B
Those who have received aid are more likely to be in favor of government relief programs than are those who have not.
Unsupported. The stimulus never mentions government relief programs or whether Hollyville residents became more likely to support such programs after receiving aid.
C
The amount of aid that victims of a disaster receive is unrelated to the extent to which the disaster is publicized.
Unsupported. We don’t know the amount of aid anyone received or its relationship to the level of publicity. Although we know about the proportion of Hollyville residents who donated, that doesn’t tell us about the amount of aid received by the people to whom Hollyville donated.
D
Once a disaster has struck them, people are more likely to aid others in need than they were before the disaster.
Strongly supported. A higher proportion of Hollyville residents donated this year compared to a few years ago after Hollyville was hit by a natural disaster (tornado) last year and received aid from others.
E
People are more likely to aid those who have experienced a hardship similar to one they themselves have experienced than to aid those who have experienced a dissimilar hardship.
Unsupported. Hollyville experienced a tornado. Other towns experienced an earthquake and flooding. There’s no basis to say that a tornado is more similar to what Hollyville experienced than is an earthquake.

25 comments