Answers to Logical Weakness Exercises

Begging the question. The judge is assuming the answer to the trial before the facts have been proven.
Non sequitur. Just because something is good for us doesn’t mean that the government should enforce compliance.
Post hoc fallacy. There is no proof that watching these particular TV shows is the cause of either high or low grades. It’s more reasonable to suppose that children who do well or poorly in school select one show or the other because of its appeal to their levels of intelligence and achievement, or its popularity among their peers.
Hasty generalization or insufficient sample. A faulty prediction for one month is not enough for an accusation of unreliability.
Two wrongs don’t make a right. The writer thinks that death and danger are unacceptable for men in combat, but subjecting women to death and danger doesn’t make these “wrongs” more acceptable.
False authority. Taste is a matter of individual preference. It would be hard to prove that Cher, however gifted an actress, is superior to anyone else in her choice of sweetener. In addition, as an actress she may be performing a role here for which she is paid—she may actually use some other sweetener at home.
Two wrongs don’t make a right. The arguer seems to infer that gambling is morally wrong; making it legal won’t make it morally right.
False comparison (or unknown facts). What was money spent for in the past? Have conditions changed that may make the expenditure of more money appropriate now?
Non sequitur. It doesn’t follow that campus newspapers select the best writers. It usually happens that they settle for those who make themselves available and turn articles in.
Begging the question. The arguer assumes that Standard English is necessary only for certain kinds of employment, but that remains to be proved. Standard English has other uses unrelated to employment.
Faulty definition. In this case discrimination means “making judicious choices,” and should not be considered pejorative. To perform their duties, which may involve physical exertion, police officers are required to meet certain physical standards.
Faulty comparison or begging the question. Qualified doctors and medical students are different. By definition a student is still being tested, and access to information in books during the testing process may defeat the purposes of testing.
Faulty definition. Chemicals are the building blocks of nature. Some may be unsafe, but they are not all synonymous with poisons by any mean. Consider H₂O, for instance.
Begging the question. The arguer assumes that the only relevant criterion for choosing courses is payment of tuition. But a student enters into an implicit agreement when he or she enrolls in a college or university to accept the conditions established by the institution in order to receive a degree.
Either/or (false dilemma) fallacy. The writer assumes that there are only two alternatives available to those who wish to marry. But there is at least one more—marriages freely chosen but not based on romantic love. Besides, we have no way of knowing how well arranged marriages worked. Staying married when it was hard to obtain a divorce doesn’t prove the success of the marriage.
Hasty generalization or insufficient sample. Three examples are not enough to support a generalization about a population of hundreds of thousands, even millions.
Hasty generalization or insufficient sample. One example of a highly intelligent athlete is not enough to prove the intelligence (or lack thereof) of a large population.
Unknown fact. There is insufficient evidence in this quotation to prove the reasons for Sasway’s failure to register, which may or may not be based on moral principles.
Post hoc fallacy. We have no way of knowing if the exercise videos are the cause of Jane Fonda’s great shape.
Faulty analogy. Harris is making an analogy between inanimate objects—buildings, cars, ham—and animate human beings, who have choices and some control over their education and behavior. Students are not products assembled out of consistent raw materials but individuals.
Post hoc fallacy. There is no evidence here that the doctrines of feminism caused women to turn to crime. Statistics show that increase in crime is better correlated with economic conditions, educational levels, exposure to illegal activities, and breakdowns in the family.
Non sequitur. It doesn’t follow that just because an activity is healthful the university should require it. There are numbers of things that are good for us that a center of academic learning does not choose to introduce into its academic curriculum.
Ad hominem. Meany is attacking the habits of the younger generation, which are different than their viewpoints (and those viewpoints are unknown).
Non sequitur. It doesn’t follow that early poverty makes a candidate more sympathetic to the problems of the poor; in fact, that may make him or her less tolerant of it.
False comparison. Russia sent troops into Hungary to crush individual freedom. In the Little Rock case the troops were used to protect the right to individual freedom.
Post Hoc fallacy. There is no evidence that the election of Governor Jones is the cause of the corruption. His election and the corruption may be coincidental, or the corruption may have existed for a long time and the cover-up has now worn through.
False dilemma (either/or) fallacy. These may not be the only alternatives for the voters; there may be other ways to improve education without a pay increase.
Post hoc fallacy. It would be hard to prove a cause-effect relationship.
False comparison. The dissimilarities between Imperial Rome and democratic 21^st century America are probably much greater than the similarities.
Post hoc fallacy. This one ought to be obvious.
False use of authority. Aristotle, working in the fourth century B.C.E., had no way of measuring whether air had weight. Galileo should have known better.
Slippery slope fallacy. The progression projected by Brustein—from Congress curtailing grant funds to Congress actually ordering the execution of artists—is hardly inevitable (or likely).