Chocolate is made from the beans of the cacao tree, which grows in tropical regions of the New World (i.e., North, Central and South America). When chocolate arrived in Europe around 1500, it was only consumed as a hot drink. In the mid-1800s, however, the Swiss invented a way to make chocolate into solid candy that people could eat. Today, millions more pounds of chocolate are produced for eating than for drinking.
Which of the following can be inferred from the statements above?
A. Today, the cacao tree cannot be grown anywhere else in the world besides the tropical regions of the Americas.
(A) is incorrect because there is nothing in the stimulus suggesting that the cacao tree ONLY grows in the American tropics. Even if it only grew there at the time it was discovered, it could be cultivated elsewhere today. Nothing in the stimulus suggests otherwise.
B. When chocolate was introduced to Europe, it was most commonly used in solid form.
(B) is incorrect because it directly contradicts the stimulus' claim that chocolate was only used as a hot drink in Europe until the 1800s.
C. The number of pounds of chocolate used to make solid candy today is greater than the number of pounds used to make chocolate drinks during the 1800s.
(C) is incorrect because there is not enough information in the stimulus to support this claim. We are told that more chocolate is made into solid candy than drinks TODAY, but we have no idea exactly how many pounds are made into candy today, nor do we know exactly how many pounds were made into drinks during the 1800s. No comparisons are made between the quantity of chocolate used for specific purposes then, versus now.
D. Chocolate was not eaten as solid candy in the New World during the 1500s.
(D) is correct because the stimulus suggests that solid chocolate candy was not invented until the 1800s by the Swiss. It can therefore be inferred that the North, Central and South American Indians of the 1500s did not know how to make it.
E. If the Swiss had not invented a way to make solid chocolate candy, chocolate would not have become as popular as it is today.
(E) is incorrect because the stimulus does not attribute chocolate's popularity to the invention of solid chocolate candy. Even though the candy is more popular today than the drinks, the drinks were made and consumed by Europeans for 300 years before the candy was invented. There is no reason to believe that chocolate drinks would not be just as popular today as the candy had the latter never been invented.
November 12, 2009
Homework #28
The Brooklyn Museum has a totem pole that was too tall to be stored in the museum's temperature-controlled storage vault. Fortunately, the totem pole can now be stored in the temperature-controlled vault thanks to the efforts of restoration artists, who have discovered a way to separate the pole into two parts for storage purposes. The artists' method allows the totem pole to be reassembled later without any noticeable change in its appearance.
The argument above depends on which of the following assumptions?
A. Neither of the two separated parts of the totem pole is too tall to fit into the vault.
B. The totem pole can be separated into two equal-sized parts.
C. The procedure for separating the two parts of the totem pole will not cost more than it would cost to replace the totem pole if it deteriorated.
D. Placing the two parts of the totem pole into the vault would not require them to remove other key artifacts from the vault.
E. The vault can be set to the proper temperature required to preserve totem pole.
The argument above depends on which of the following assumptions?
A. Neither of the two separated parts of the totem pole is too tall to fit into the vault.
B. The totem pole can be separated into two equal-sized parts.
C. The procedure for separating the two parts of the totem pole will not cost more than it would cost to replace the totem pole if it deteriorated.
D. Placing the two parts of the totem pole into the vault would not require them to remove other key artifacts from the vault.
E. The vault can be set to the proper temperature required to preserve totem pole.
November 10, 2009
Homework #26 Answer
Judges in the Kingsborough Student Essay Contest disqualified Sam's entry because it broke one of the contest rules. The rules specified that students should place their name ONLY on the cover page of the essay, which the judges would not see, to make sure they judged it fairly and without bias against the individual student. Sam, however, put his name on each and every page of his essay. Nevertheless, Sam's entry should be allowed to qualify, because Sam's parents recently got divorced, and it's been very hard for him.
Which one of the following explains why this is a flawed response to the judges' decision?
A. It presents a conclusion without providing supporting evidence.
(A) is incorrect because the conclusion is supported by evidence, even though that evidence is completely irrelevant. The conclusion is that Sam's essay should be allowed to qualify; the "evidence" is that his parents recently got divorced and he is struggling with that. The reasons why Sam broke the rule are irrelevant, because the rule regarding the placement of the student's name does not take the student's reasons for doing it wrong into account. This is true for most rules. The best example is traffic violations. If you speed, or run a stop sign, it doesn't matter why you did it; you're guilty unless you can prove that you did not actually speed, or that you did not actually run the stop sign. Why you did it is of no consequence, even if you had a really good reason. You're still guilty and still have to pay the fine.
B. It treats a factor that may cause a particular outcome as the only possible cause of that outcome.
(B) is incorrect whether the "outcome" refers to Sam's mistake or the resulting disqualification. In the case of Sam's mistake, the cause is irrelevant. It doesn't matter why he wrote his name on every page of the essay. In the case of the disqualification, again it doesn't matter that there are other reasons why he could have been disqualified. The fact that he was disqualified because he wrote his name on every page is the only thing that matters.
C. It focuses on a trivial, unimportant aspect of the judges' argument.
(C) is incorrect because there is nothing trivial or unimportant about any aspect of the judges' argument. There was a rule, Sam broke the rule, and he broke it in such a way as to completely defeat the purpose of having the rule in the first place.
D. It incorrectly states the facts that formed the basis of the judges' decision.
(D) is incorrect because there is nothing in the stimulus to suggest that Sam did not actually break the rule, or that the judges are mistaken (or lying) about his name being on every page.
E. It appeals to the judges' emotions instead of addressing their reason for disqualifying the essay.
(E) is correct. The argument is an appeal for sympathy, nothing more. It suggests that the judges should ignore the fact that Sam broke the rule and admit his essay anyway because they feel sorry for him. Whether you agree with this or not, the fact remains that Sam broke the rule and defeated its purpose; there is no logical reason or rational basis for admitting his essay under these circumstances.
Which one of the following explains why this is a flawed response to the judges' decision?
A. It presents a conclusion without providing supporting evidence.
(A) is incorrect because the conclusion is supported by evidence, even though that evidence is completely irrelevant. The conclusion is that Sam's essay should be allowed to qualify; the "evidence" is that his parents recently got divorced and he is struggling with that. The reasons why Sam broke the rule are irrelevant, because the rule regarding the placement of the student's name does not take the student's reasons for doing it wrong into account. This is true for most rules. The best example is traffic violations. If you speed, or run a stop sign, it doesn't matter why you did it; you're guilty unless you can prove that you did not actually speed, or that you did not actually run the stop sign. Why you did it is of no consequence, even if you had a really good reason. You're still guilty and still have to pay the fine.
B. It treats a factor that may cause a particular outcome as the only possible cause of that outcome.
(B) is incorrect whether the "outcome" refers to Sam's mistake or the resulting disqualification. In the case of Sam's mistake, the cause is irrelevant. It doesn't matter why he wrote his name on every page of the essay. In the case of the disqualification, again it doesn't matter that there are other reasons why he could have been disqualified. The fact that he was disqualified because he wrote his name on every page is the only thing that matters.
C. It focuses on a trivial, unimportant aspect of the judges' argument.
(C) is incorrect because there is nothing trivial or unimportant about any aspect of the judges' argument. There was a rule, Sam broke the rule, and he broke it in such a way as to completely defeat the purpose of having the rule in the first place.
D. It incorrectly states the facts that formed the basis of the judges' decision.
(D) is incorrect because there is nothing in the stimulus to suggest that Sam did not actually break the rule, or that the judges are mistaken (or lying) about his name being on every page.
E. It appeals to the judges' emotions instead of addressing their reason for disqualifying the essay.
(E) is correct. The argument is an appeal for sympathy, nothing more. It suggests that the judges should ignore the fact that Sam broke the rule and admit his essay anyway because they feel sorry for him. Whether you agree with this or not, the fact remains that Sam broke the rule and defeated its purpose; there is no logical reason or rational basis for admitting his essay under these circumstances.
Homework #27
Chocolate is made from the beans of the cacao tree, which grows in tropical regions of the New World (i.e., North, Central and South America). When chocolate arrived in Europe around 1500, it was only consumed as a hot drink. In the mid-1800s, however, the Swiss invented a way to make chocolate into solid candy that people could eat. Today, millions more pounds of chocolate are produced for eating than for drinking.
Which of the following can be inferred from the statements above?
A. Today, the cacao tree cannot be grown anywhere else in the world besides the tropical regions of the Americas.
B. When chocolate was introduced to Europe, it was most commonly used in solid form.
C. The number of pounds of chocolate used to make solid candy today is greater than the number of pounds used to make chocolate drinks during the 1800s.
D. Chocolate was not eaten as solid candy in the New World during the 1500s.
E. If the Swiss had not invented a way to make solid chocolate candy, chocolate would not have become as popular as it is today.
Which of the following can be inferred from the statements above?
A. Today, the cacao tree cannot be grown anywhere else in the world besides the tropical regions of the Americas.
B. When chocolate was introduced to Europe, it was most commonly used in solid form.
C. The number of pounds of chocolate used to make solid candy today is greater than the number of pounds used to make chocolate drinks during the 1800s.
D. Chocolate was not eaten as solid candy in the New World during the 1500s.
E. If the Swiss had not invented a way to make solid chocolate candy, chocolate would not have become as popular as it is today.
Homework #25 Answer
If someone puts too much pressure on the bottom shelf of a bookcase, the entire bookcase will collapse. Shelly's bookcase has collapsed. Therefore, someone must have put too much pressure on the bottom shelf.
Which one of the following criticisms best describes a weakness in the argument above?
A. It supports its conclusion with irrelevant evidence.
(A) is incorrect because the evidence, while inadequate to support the conclusion, is nonetheless relevant. The evidence here is that the bookcase collapsed, and that putting too much pressure on the bottom shelf of any bookcase will cause that bookcase to collapse. The conclusion is that the collapse of Shelly's bookcase must have happened because someone put too much pressure on the bottom shelf. The evidence is relevant because it makes the conclusion more likely to be true; if the bookcase collapsed, and too much pressure on the bottom shelf can cause it, then the collapse of the bookcase could suggest that someone put too much pressure on the bottom shelf. The problem is that the evidence does not by itself prove that the conclusion must be true.
B. It changes the meaning of the word "collapse" from "partial collapse" to "full collapse."
(B) is incorrect because the argument does not hinge on the definition of "collapse." This is a simple reverse cause-and-effect argument; it doesn't matter whether the collapse was "partial" or "full," or whether the author meant "partial" or "full" when he wrote the word "collapse." At issue is the cause of the collapse, not the extent of it.
C. It concludes that an outcome must have been caused by one particular factor, which may be only one of many possible causes of that outcome.
(C) is correct. As discussed above, the flaw in the argument is that the author has assumed the cause based only on the outcome and nothing more. This classic logical fallacy came up in Homework #23 and #24 as well. Just because X can cause Y, or has a tendency to cause Y, does not mean that if Y occurs it must (or could only) have been caused by X. Only if we know that there is no other possible cause can we assume the cause from the outcome alone.
D. It overlooks the possibility that some bookshelves have only one shelf.
(D) is incorrect because "the possibility that some bookshelves have only one shelf" does not make it more or less likely that the collapse of this particular bookcase was caused by pressure on the bottom shelf. Therefore the fact that the possibility was "overlooked" is not a weakness, because there is nothing wrong with ignoring irrelevant factors when making an argument. Indeed, ignoring irrelevancies actually strengthens the argument.
E. It draws an overly broad conclusion from small, insignificant pieces of evidence.
(E) is incorrect because the conclusion is not "overly broad;" it is in fact overly narrow, assuming only one of many possible causes for a specific outcome. Neither is the evidence (i.e., the collapse of the bookcase) "small" or "insignificant."
Which one of the following criticisms best describes a weakness in the argument above?
A. It supports its conclusion with irrelevant evidence.
(A) is incorrect because the evidence, while inadequate to support the conclusion, is nonetheless relevant. The evidence here is that the bookcase collapsed, and that putting too much pressure on the bottom shelf of any bookcase will cause that bookcase to collapse. The conclusion is that the collapse of Shelly's bookcase must have happened because someone put too much pressure on the bottom shelf. The evidence is relevant because it makes the conclusion more likely to be true; if the bookcase collapsed, and too much pressure on the bottom shelf can cause it, then the collapse of the bookcase could suggest that someone put too much pressure on the bottom shelf. The problem is that the evidence does not by itself prove that the conclusion must be true.
B. It changes the meaning of the word "collapse" from "partial collapse" to "full collapse."
(B) is incorrect because the argument does not hinge on the definition of "collapse." This is a simple reverse cause-and-effect argument; it doesn't matter whether the collapse was "partial" or "full," or whether the author meant "partial" or "full" when he wrote the word "collapse." At issue is the cause of the collapse, not the extent of it.
C. It concludes that an outcome must have been caused by one particular factor, which may be only one of many possible causes of that outcome.
(C) is correct. As discussed above, the flaw in the argument is that the author has assumed the cause based only on the outcome and nothing more. This classic logical fallacy came up in Homework #23 and #24 as well. Just because X can cause Y, or has a tendency to cause Y, does not mean that if Y occurs it must (or could only) have been caused by X. Only if we know that there is no other possible cause can we assume the cause from the outcome alone.
D. It overlooks the possibility that some bookshelves have only one shelf.
(D) is incorrect because "the possibility that some bookshelves have only one shelf" does not make it more or less likely that the collapse of this particular bookcase was caused by pressure on the bottom shelf. Therefore the fact that the possibility was "overlooked" is not a weakness, because there is nothing wrong with ignoring irrelevant factors when making an argument. Indeed, ignoring irrelevancies actually strengthens the argument.
E. It draws an overly broad conclusion from small, insignificant pieces of evidence.
(E) is incorrect because the conclusion is not "overly broad;" it is in fact overly narrow, assuming only one of many possible causes for a specific outcome. Neither is the evidence (i.e., the collapse of the bookcase) "small" or "insignificant."
November 9, 2009
Homework #26
Judges in the Kingsborough Student Essay Contest disqualified Sam's entry because it broke one of the contest rules. The rules specified that students should place their name ONLY on the cover page of the essay, which the judges would not see, to make sure they judged it fairly and without bias against the individual student. Sam, however, put his name on each and every page of his essay. Nevertheless, Sam's entry should be allowed to qualify, because Sam's parents recently got divorced, and it's been very hard for him.
Which one of the following explains why this is a flawed response to the judges' decision?
A. It presents a conclusion without providing supporting evidence.
B. It treats a factor that may cause a particular outcome as the only possible cause of that outcome.
C. It focuses on a trivial, unimportant aspect of the judges' argument.
D. It incorrectly states the facts that formed the basis of the judges' decision.
E. It appeals to the judges' emotions instead of addressing their reason for disqualifying the essay.
Which one of the following explains why this is a flawed response to the judges' decision?
A. It presents a conclusion without providing supporting evidence.
B. It treats a factor that may cause a particular outcome as the only possible cause of that outcome.
C. It focuses on a trivial, unimportant aspect of the judges' argument.
D. It incorrectly states the facts that formed the basis of the judges' decision.
E. It appeals to the judges' emotions instead of addressing their reason for disqualifying the essay.
Homework #24 Answer
The advantages of a college education are much too precious to waste on students who are not seriously dedicated to learning and studying. Administrators should strictly enforce the idea that students must earn the privilege of enrolling in college, and then must earn the privilege of staying there. Any student who fails a course should be immediately dismissed from the university, so that a more deserving student may take his place.
Which one of the following is the best rebuttal of the argument above?
A. A student should not be expected to fulfill college requirements unless he gets to choose the courses he wants to take.
(A) is incorrect because it's an excuse that's unrelated to the author's premise. The author argues that students who fail courses should be summarily thrown out of college, because the failure indicates that they are not "seriously dedicated to learning and studying." This, of course, is a faulty assumption. However, the flaw in the argument is not that a student should get to choose his own courses, because choice of courses has no direct bearing on dedication and seriousness. This choice addresses only the author's conclusion, not the reasons behind it.
B. The university may not have made the student fully aware of the demands of its curriculum and the intensity of study required.
(B) is also incorrect because it's also an excuse that has no bearing on the student's dedication and seriousness, which are the crux of the author's argument. Like (A), it only addresses the author's conclusion, not the reasons behind it. The author's point is that students who are not dedicated and serious should not be in college; shifting the blame to a third party based on unrelated factors does not undermine the original premise.
C. To dismiss a student who fails a course is to place achievement over the student's individual right to an education.
(C) is incorrect because it doesn't make a whole lot of sense. To the extent that a student has an "individual right to an education," that right is to the opportunity, not the outcome. In other words, a student has a right to be educated but does not have a right to receive high grades, or even to pass his courses. However, even if such a right does exist, it ends with secondary school; going to college is not a right. Further, like all other rights, it can be forfeited if one does not live up to one's responsibilities. Therefore there is nothing wrong with "plac[ing] achievement over the student's individual right to an education," especially in the college context. This idea is not incompatible with the author's argument, therefore (C) does not undermine it.
D. Scholarship is only one of the possible contributions that a student might make to the university community.
(D) is incorrect because it is also not incompatible with the author's argument. "Scholarship" here refers to a student's academic ability and performance, as opposed to "a scholarship" which would refer to a monetary grant of assistance based thereon. The idea that a student might contribute to a university community in non-academic ways, such as by playing football or having his family donate a building, does not undermine the author's argument about seriousness and dedication. It's a weak rebuttal.
E. A highly dedicated student may still fail a course for other reasons, which are unrelated to his dedication.
(E) is the best rebuttal to the author's argument because of the author's faulty assumption. The author assumes that if a student fails a course, it must mean that he is not serious or dedicated to his studies and should therefore be expelled, so someone who is serious and dedicated can take his place. The author fails to consider that serious, dedicated students may nonetheless fail courses for other reasons. Whether those reasons constitute mere excuses is beside the point; this choice undermines the author's flawed assumption, and is therefore the best rebuttal.
Which one of the following is the best rebuttal of the argument above?
A. A student should not be expected to fulfill college requirements unless he gets to choose the courses he wants to take.
(A) is incorrect because it's an excuse that's unrelated to the author's premise. The author argues that students who fail courses should be summarily thrown out of college, because the failure indicates that they are not "seriously dedicated to learning and studying." This, of course, is a faulty assumption. However, the flaw in the argument is not that a student should get to choose his own courses, because choice of courses has no direct bearing on dedication and seriousness. This choice addresses only the author's conclusion, not the reasons behind it.
B. The university may not have made the student fully aware of the demands of its curriculum and the intensity of study required.
(B) is also incorrect because it's also an excuse that has no bearing on the student's dedication and seriousness, which are the crux of the author's argument. Like (A), it only addresses the author's conclusion, not the reasons behind it. The author's point is that students who are not dedicated and serious should not be in college; shifting the blame to a third party based on unrelated factors does not undermine the original premise.
C. To dismiss a student who fails a course is to place achievement over the student's individual right to an education.
(C) is incorrect because it doesn't make a whole lot of sense. To the extent that a student has an "individual right to an education," that right is to the opportunity, not the outcome. In other words, a student has a right to be educated but does not have a right to receive high grades, or even to pass his courses. However, even if such a right does exist, it ends with secondary school; going to college is not a right. Further, like all other rights, it can be forfeited if one does not live up to one's responsibilities. Therefore there is nothing wrong with "plac[ing] achievement over the student's individual right to an education," especially in the college context. This idea is not incompatible with the author's argument, therefore (C) does not undermine it.
D. Scholarship is only one of the possible contributions that a student might make to the university community.
(D) is incorrect because it is also not incompatible with the author's argument. "Scholarship" here refers to a student's academic ability and performance, as opposed to "a scholarship" which would refer to a monetary grant of assistance based thereon. The idea that a student might contribute to a university community in non-academic ways, such as by playing football or having his family donate a building, does not undermine the author's argument about seriousness and dedication. It's a weak rebuttal.
E. A highly dedicated student may still fail a course for other reasons, which are unrelated to his dedication.
(E) is the best rebuttal to the author's argument because of the author's faulty assumption. The author assumes that if a student fails a course, it must mean that he is not serious or dedicated to his studies and should therefore be expelled, so someone who is serious and dedicated can take his place. The author fails to consider that serious, dedicated students may nonetheless fail courses for other reasons. Whether those reasons constitute mere excuses is beside the point; this choice undermines the author's flawed assumption, and is therefore the best rebuttal.
November 4, 2009
Homework #25
If someone puts too much pressure on the bottom shelf of a bookcase, the entire bookcase will collapse. Shelly's bookcase has collapsed. Therefore, someone must have put too much pressure on the bottom shelf.
Which one of the following criticisms best describes a weakness in the argument above?
A. It supports its conclusion with irrelevant evidence.
B. It changes the meaning of the word "collapse" from "partial collapse" to "full collapse."
C. It concludes that an outcome must have been caused by one particular factor, which may be only one of many possible causes of that outcome.
D. It overlooks the possibility that some bookshelves have only one shelf.
E. It draws an overly broad conclusion from small, insignificant pieces of evidence.
Which one of the following criticisms best describes a weakness in the argument above?
A. It supports its conclusion with irrelevant evidence.
B. It changes the meaning of the word "collapse" from "partial collapse" to "full collapse."
C. It concludes that an outcome must have been caused by one particular factor, which may be only one of many possible causes of that outcome.
D. It overlooks the possibility that some bookshelves have only one shelf.
E. It draws an overly broad conclusion from small, insignificant pieces of evidence.
November 3, 2009
Homework #23 Answer
Children never develop strong self-esteem if they are guided by adults who criticize them. Therefore, if children are guided by adults who never criticize them, they will develop strong self-esteem.
Which one of the following arguments is most similar to the flawed pattern of reasoning used in the argument above?
This was a very difficult question. Parallel reasoning questions are probably the hardest, because you have to completely ignore the subject matter and substance of the stimulus and only consider its structure. Whether the argument in the answer choice is true, valid, believable or reasonable is entirely irrelevant. In this case, the question stem actually tells you that the argument in the stimulus is wrong because it depends on flawed reasoning, which means you already know it's not a reasonable argument. The question is not which of the following arguments seems reasonable, or likely to be correct. The question is which of the following arguments makes the same mistake of logic that the stimulus does, and is unreasonable for the same reason.
Completely ignoring the subject matter, and looking only at the structure of the argument, the stimulus is suggesting a cause-and-effect relationship where the occurrence of one event (X) causes the non-occurrence of another (Y). On other words, if X happens, Y will not happen. The flaw in the logic is the conclusion the author draws based on this relationship, i.e., the idea that if X does not happen, Y will happen, which is not logically sound. Just because X prevents Y from occurring, doesn't necessarily mean that the absence of X will cause Y to occur. Another example:
If you buy a sprinkler system, your house won't burn down. Therefore, if you don't buy a sprinkler system, your house will burn down.
This is flawed reasoning. The absence of a sprinkler system cannot by itself cause your house to burn down, nor does it guarantee by itself that your house will burn down. Of course, if your house catches fire, that's something else, but it's not part of the equation. The absence of a sprinkler system cannot cause it to catch fire, even though it might prevent you from putting that fire out. Just like in the stimulus; the absence of criticism from adults does not by itself guarantee that a child will develop high self-esteem, although it might contribute to that result.
The flawed logic can be formulated thusly: If X, then not Y; therefore, if not X, then Y.
A. Even though Hannah studies hard, she does not get good grades. Therefore, Hannah should not try to get good grades by studying hard.
(A) is incorrect because even though it is unreasonable, it is not so for the same reason as the stimulus. What's missing with respect to the stimulus is that the second sentence does not purport to guarantee that Hannah will get good grades if she does not study hard. (A) suggests not so much a cause-and-effect relationship but a method-and-goal relationship, specifically that the method has not thus far worked to achieve the goal, therefore Hannah should not continue to try this method. It's not entirely unreasonable; if a method doesn't work, try another method. In the context of this subject matter, though, it's bad advice.
B. Telephone salesmen who have bad phone manners do not sell any products. Therefore, telephone salesmen with low sales records must have bad phone manners.
(B) is also unreasonable but it's also incorrect. The flaw in the logic here is not that the non-occurrence of X guarantees the occurrence of Y. It's that X tends to cause Y, so if Y occurs, then X must be the cause. It's a simple cause-and-effect equation, simpler than the stimulus in that it merely inverts the cause and effect. Even though Y is a negative event ("...do not sell any products"), it's in the negative on both sides of the equation. The stimulus' pattern reverses the negations between X and Y (If X, then NOT Y; therefore if NOT X, then Y). This choice does not (If X, then NOT Y; therefore if NOT Y, then X).
C. Using the store's new knitting machine, the knitting store owner made twice as many sweaters yesterday as she did the day before. Therefore, if she uses the knitting machine again tomorrow, she will make twice as many sweaters as she did today.
(C) is incorrect because it also does not match the pattern of the stimulus' argument. For one thing, there are no negative events here. The statement is flawed because it assumes that because one event caused a changed outcome, a repetition of that event must cause the change (not the event itself) to occur again. The statement is absurd because the change in the outcome was attributable to a changed condition. If the new condition subsequently remains the same and does not change again, then the change in the outcome will not recur.
D. Puppies who are not used to being with people do not interact comfortably with a large group of people. Therefore, the more a puppy is used to being with people, the more comfortable he will be with a large group of people.
(D) is incorrect because it's not flawed; it's a perfectly reasonable statement.
E. People who take calcium supplements do not increase their risk of heart disease. Therefore, people who do not take calcium supplements will increase their risk of heart disease.
(E) is correct because it's the only choice that matches the pattern of the stimulus (If X, then not Y; therefore, if not X, then Y). In this case, X is the taking of calcium supplements, and Y is an increased risk of heart disease.
Which one of the following arguments is most similar to the flawed pattern of reasoning used in the argument above?
This was a very difficult question. Parallel reasoning questions are probably the hardest, because you have to completely ignore the subject matter and substance of the stimulus and only consider its structure. Whether the argument in the answer choice is true, valid, believable or reasonable is entirely irrelevant. In this case, the question stem actually tells you that the argument in the stimulus is wrong because it depends on flawed reasoning, which means you already know it's not a reasonable argument. The question is not which of the following arguments seems reasonable, or likely to be correct. The question is which of the following arguments makes the same mistake of logic that the stimulus does, and is unreasonable for the same reason.
Completely ignoring the subject matter, and looking only at the structure of the argument, the stimulus is suggesting a cause-and-effect relationship where the occurrence of one event (X) causes the non-occurrence of another (Y). On other words, if X happens, Y will not happen. The flaw in the logic is the conclusion the author draws based on this relationship, i.e., the idea that if X does not happen, Y will happen, which is not logically sound. Just because X prevents Y from occurring, doesn't necessarily mean that the absence of X will cause Y to occur. Another example:
If you buy a sprinkler system, your house won't burn down. Therefore, if you don't buy a sprinkler system, your house will burn down.
This is flawed reasoning. The absence of a sprinkler system cannot by itself cause your house to burn down, nor does it guarantee by itself that your house will burn down. Of course, if your house catches fire, that's something else, but it's not part of the equation. The absence of a sprinkler system cannot cause it to catch fire, even though it might prevent you from putting that fire out. Just like in the stimulus; the absence of criticism from adults does not by itself guarantee that a child will develop high self-esteem, although it might contribute to that result.
The flawed logic can be formulated thusly: If X, then not Y; therefore, if not X, then Y.
A. Even though Hannah studies hard, she does not get good grades. Therefore, Hannah should not try to get good grades by studying hard.
(A) is incorrect because even though it is unreasonable, it is not so for the same reason as the stimulus. What's missing with respect to the stimulus is that the second sentence does not purport to guarantee that Hannah will get good grades if she does not study hard. (A) suggests not so much a cause-and-effect relationship but a method-and-goal relationship, specifically that the method has not thus far worked to achieve the goal, therefore Hannah should not continue to try this method. It's not entirely unreasonable; if a method doesn't work, try another method. In the context of this subject matter, though, it's bad advice.
B. Telephone salesmen who have bad phone manners do not sell any products. Therefore, telephone salesmen with low sales records must have bad phone manners.
(B) is also unreasonable but it's also incorrect. The flaw in the logic here is not that the non-occurrence of X guarantees the occurrence of Y. It's that X tends to cause Y, so if Y occurs, then X must be the cause. It's a simple cause-and-effect equation, simpler than the stimulus in that it merely inverts the cause and effect. Even though Y is a negative event ("...do not sell any products"), it's in the negative on both sides of the equation. The stimulus' pattern reverses the negations between X and Y (If X, then NOT Y; therefore if NOT X, then Y). This choice does not (If X, then NOT Y; therefore if NOT Y, then X).
C. Using the store's new knitting machine, the knitting store owner made twice as many sweaters yesterday as she did the day before. Therefore, if she uses the knitting machine again tomorrow, she will make twice as many sweaters as she did today.
(C) is incorrect because it also does not match the pattern of the stimulus' argument. For one thing, there are no negative events here. The statement is flawed because it assumes that because one event caused a changed outcome, a repetition of that event must cause the change (not the event itself) to occur again. The statement is absurd because the change in the outcome was attributable to a changed condition. If the new condition subsequently remains the same and does not change again, then the change in the outcome will not recur.
D. Puppies who are not used to being with people do not interact comfortably with a large group of people. Therefore, the more a puppy is used to being with people, the more comfortable he will be with a large group of people.
(D) is incorrect because it's not flawed; it's a perfectly reasonable statement.
E. People who take calcium supplements do not increase their risk of heart disease. Therefore, people who do not take calcium supplements will increase their risk of heart disease.
(E) is correct because it's the only choice that matches the pattern of the stimulus (If X, then not Y; therefore, if not X, then Y). In this case, X is the taking of calcium supplements, and Y is an increased risk of heart disease.
November 2, 2009
Homework #24
The advantages of a college education are much too precious to waste on students who are not seriously dedicated to learning and studying. Administrators should strictly enforce the idea that students must earn the privilege of enrolling in college, and then must earn the privilege of staying there. Any student who fails a course should be immediately dismissed from the university, so that a more deserving student may take his place.
Which one of the following is the best rebuttal of the argument above?
A. A student should not be expected to fulfill college requirements unless he gets to choose the courses he wants to take.
B. The university may not have made the student fully aware of the demands of its curriculum and the intensity of study required.
C. To dismiss a student who fails a course is to place achievement over the student's individual right to an education.
D. Scholarship is only one of the possible contributions that a student might make to the university community.
E. A highly dedicated student may still fail a course for other reasons, which are unrelated to his dedication.
Which one of the following is the best rebuttal of the argument above?
A. A student should not be expected to fulfill college requirements unless he gets to choose the courses he wants to take.
B. The university may not have made the student fully aware of the demands of its curriculum and the intensity of study required.
C. To dismiss a student who fails a course is to place achievement over the student's individual right to an education.
D. Scholarship is only one of the possible contributions that a student might make to the university community.
E. A highly dedicated student may still fail a course for other reasons, which are unrelated to his dedication.
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