Proofs relying crucially on computers provide less certainty than do proofs not requiring computers. Human cognition alone cannot verify computer-dependent proofs; such proofs can never provide the degree of certainty that attends our judgments concerning, for instance, simple arithmetical facts, which can be verified by human calculation. Of course, in these cases one often uses electronic calculators, but here the computer is a convenience rather than a supplement to human cognition.

Summary
Proofs that rely on computers give less certainty than do proofs that don’t require using computers. This is because humans alone can’t verify computer-dependent proofs. With proofs that don’t require computers, we can verify them by human calculation. Note that although we often use computers to verify these non-computer-dependent proofs, we’re using these computers for convenience, not because we depend on the computers.

Strongly Supported Conclusions
Computers can provide assistance concerning tasks for which computers are not necessary.
Whether humans can verify a proof without the aid of computers is a factor in the level of certainty that the proof provides.

A
Only if a proof’s result is arrived at without the help of a computer can one judge with any degree of certainty that the proof is correct.
Unsupported. The stimulus acknowledges that computers can aid in the proof of non-computer-dependent proofs. So, it might be possible to judge that such proofs are correct even if we arrive at those proofs with the aid of computers.
B
We can never be completely sure that proofs relying crucially on computers do not contain errors that humans do not detect.
Strongly supported. We’re told that human cognition can’t verify computer-dependent proofs. And if they can’t verify such proofs, that suggests they can’t detect every single error in those proofs. So, some errors may slip by that humans can’t detect.
C
Whenever a computer replaces human calculation in a proof, the degree of certainty provided by the proof is reduced.
Unsupported. The stimulus acknowledges that we can use computers for convenience for non-computer-dependent proofs. And if such computer makes an error, we can catch the error through human calculation.
D
If one can corroborate something by human calculation, one can be completely certain of it.
Unsupported. Human ability to confirm something by calculation may mean we can be more certain about the thing, but that doesn’t imply we can be “completely” certain of it.
E
It is impossible to supplement the cognitive abilities of humans by means of artificial devices such as computers.
Unsupported. The stimulus tells us that when we use calculators to perform calculations that could be done by humans, we are not using calculators as a supplement. But that doesn’t imply it’s impossible for devices to supplement human cognition in other contexts.

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Madden: Industrialists address problems by simplifying them, but in farming that strategy usually leads to oversimplification. For example, industrialists see water retention and drainage as different and opposite functions—that good topsoil both drains and retains water is a fact alien to industrial logic. To facilitate water retention, they use a terrace or a dam; to facilitate drainage, they use drain tile, a ditch, or a subsoiler. More farming problems are created than solved when agriculture is the domain of the industrialist, not of the farmer.

Summary

Industrialists solve problems by simplifying them, but if this strategy were applied to farming the result would be oversimplification. For example, an industrialist sees water retention and drainage as opposite functions when in fact these factors aren’t necessarily so. Industrialists would facilitate retention by using a terrace or dam, and they would facilitate drainage using a drain tile, ditch, or subsoiler. In farming, more problems are created than solved using the industrialists’ methods.

Strongly Supported Conclusions

Problems associated with farming should be addressed by recognizing the complexity of a given problem.

A
The handling of water drainage and retention is the most important part of good farming.

This answer is unsupported. We don’t know whether drainage and retention are the most important factors of good farming. These factors were given as an example to illustrate how industrialists would oversimplify these issues.

B
The problems of farming should be viewed in all their complexity.

This answer is strongly supported. The Madden’s criticism with industrialists is that industrialists tend to simplify problems. Applying this strategy to farming would result in oversimplification.

C
Farmers are better than anyone else at solving farming problems.

This answer is unsupported. We don’t know whether farmers are better than anyone else. At best, we only know that farmers are better suited than industrialists to solve farming problems.

D
Industrial solutions for problems in farming should never be sought.

This answer is unsupported. Saying industrial solutions should “never” be sought is too strong. We only know from the stimulus that these solutions usually lead to oversimplification. There could be some instances where these solutions don’t lead to oversimplifications.

E
The approach to problem solving typical of industrialists is fundamentally flawed.

This answer is unsupported. The Madden is not arguing that an industrialist approach to solving problems is “fundamentally flawed.” Rather, the Madden is arguing that these approaches are flawed when specifically applied to farming.


17 comments

A recent study confirmed that salt intake tends to increase blood pressure and found that, as a result, people with high blood pressure who significantly cut their salt intake during the study had lower blood pressure by the end of the study. However, it was also found that some people who had very high salt intake both before and throughout the study maintained very low blood pressure.

"Surprising" Phenomenon
Why do some people who consume lots of salt have high blood pressure while others have very low blood pressure?

Objective
Any hypothesis explaining these results must state a distinction among people with high salt intake that explains why some have high blood pressure while others have low blood pressure. It may indicate that people react differently to a high salt intake, or it may be unrelated to salt intake altogether.

A
Study participants with high blood pressure who cut their salt intake only slightly during the study did not have significantly lower blood pressure by the end of the study.
This does not explain why people with high salt intake have such different blood pressures. It draws no distinction between groups of people who consume lots of salt.
B
Salt intake is only one of several dietary factors associated with high blood pressure.
This would explain why people with low salt intake have high blood pressure, but not why those with high salt intake have low blood pressure. It does not state that these dietary factors make low blood pressure possible despite a high salt intake.
C
For most people who have high blood pressure, reducing salt intake is not the most effective dietary change they can make to reduce their blood pressure.
This refers only to people with high blood pressure, and does not explain how people with high salt intake have very low blood pressure. It is not stated whether these other dietary changes will cause a person to have very low blood pressure.
D
At the beginning of the study, some people who had very low salt intake also had very high blood pressure.
This refers to people with low salt intake, not high salt intake. It does not explain why those with high salt intake can have low blood pressure.
E
Persons suffering from abnormally low blood pressure have heightened salt cravings, which ensure that their blood pressure does not drop too low.
This explains why some people with high salt intake have low blood pressure. They have very low blood pressure in the first place, and their salt consumption prevents it from dropping even lower.

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