PHI 1100 Informal Logic Cumulative Exercises Assignment
The following examples cover all the various sorts of arguments examined in this book, with the exception of statistical fallacies. As always, some are fallacious and some are not. For each example, first tell what form the argument is (such as questionable cause); then determine whether the argument is or is not fallacious.
The argument forms we have examined are as follows:
- Ad hominem: sometimes a fallacy, sometimes not Inverse ad hominem: sometimes a fallacy, sometimes not Strawman: always a fallacy
- Irrelevant reason (or red herring): always a fallacy
- Appeal to ignorance: always a fallacy
- Ambiguity: always a fallacy
- Appeal to authority: sometimes a fallacy, sometimes not
- Appeal to popularity: always a fallacy
- Appeal to tradition (traditional wisdom): always a fallacy
- Analogies (deductive, inductive, figurative): sometimes fallacious, sometimes legitimate
- Analogical literalism: always a fallacy
- Slippery slope: sometimes a fallacy, sometimes not
- Dilemma arguments: sometimes the fallacy of false dilemma, sometimes a genuine dilemma
- Golden mean: always a fallacy (though it is not inherently fallacious to advocate a moderate position)
- Begging the question: always a fallacy
- Self-sealing argument: always a fallacy
- Complex question: always a fallacy (though embedded noncontroversial assumptions do not commit this fallacy)
- Modus ponens: not a fallacy, a valid argument form
- Modus tollens: not a fallacy, a valid argument form
- Denying the antecedent: always a fallacy
- Affirming the consequent: always a fallacy
Causal arguments: some are legitimate, some commit the fallacy of questionable cause.
Guaranteeing health-care coverage for every citizen of the United States would be too expensive; on the other hand, as a wealthy country, it is wrong for the United States to have almost 40 million people without health coverage. A good solution is to guarantee health care for all citizens under age 18, but not provide guaranteed health care for all adults.
If everyone fails this final exam, then it is too hard. But certainly not everyone will fail this final exam, so clearly the exam is not too hard.
If there was no effective communications in New Orleans after Hurricane Katrina, then the Federal Emergency Management Administration (FEMA) did a lousy planning job. So obviously FEMA did a lousy job, because New Orleans did not have effective communications after Hurricane Katrina.
Darling, you shouldn’t be angry at me; I’ve never been unfaithful to you. OK, I admit that I did spend that weekend with Tony, and then there was that time I had a little fling with Robert, and last year I did slip off to Abe’s apartment a few times during lunch, and maybe there were one or two others. But I wasn’t really cheating on you, because I was always faithful to you in my heart, even if my body occasionally strayed. So I’ve never really been unfaithful.
We are now spending millions of dollars on increased airport and air travel security. But it’s a total waste of time and money. Either the new security measures must make air travel absolutely safe, or they are totally useless. But there’s no way airport security measures can make air travel perfectly safe; after all, there is always the possibility of pilot error or mechanical failure. So clearly we must conclude that the airport security measures are useless.
We recently did a study of graduating seniors, and we found that students who made a grade of A in critical thinking were significantly more likely to graduate with honors than were students who had never taken critical thinking. So clearly doing well in the critical thinking class causes students to make higher grades in all their classes.
There were many great artists of the Renaissance period—Michelangelo, Da Vinci, Raphael, and many others. Some art experts say Da Vinci was the best, some say Michelangelo was greatest, some favor Raphael, and others have their own favorites. But my art history professor—Alice Krokowski, who has her doctorate in art history from Yale—says that the greatest of all Renaissance artists was Albrecht Durer. So that should settle it: Durer was the greatest artist of the Renaissance period.
If the United States had been a democracy in 1800, then all adult U.S. citizens would have had the right to vote. But certainly it was not the case that all U.S. citizens could vote: women, African Americans, and people without property were all denied the right to vote in 1800. So clearly the United States was not a democracy in 1800.
Look, we all agree that every child, rich or poor, should be provided with a decent education, since without a good education one does not have a real opportunity to succeed, right? So likewise, we should also make sure that every child has good health care, since lack of good health care also destroys a child’s opportunity for success: a child who is sick or chronically unhealthy is deprived of opportunity, just like a child who is not taught to read or write.
Some people believe that we should legalize marijuana for medicinal purposes: for example, marijuana can be very effective in relieving severe nausea following certain types of cancer treatments. But it would be a mistake to legalize medicinal marijuana, because we should never legalize marijuana for any use whatsoever.
It has often been claimed that the U.S. Air Force keeps a secret file—a top-secret “green book”— containing conclusive evidence of extraterrestrial visitations to Earth. Now of course the Air Force always denies such a secret file, but they have never provided one shred of hard evidence to prove that such a file does not exist. Until they offer such proof, it is only reasonable to conclude that there really is such a secret file.
Some people argue that capital punishment is necessary, because it is the only appropriate punishment for those who commit the most atrocious and depraved crimes. However, we should not pay any attention to such arguments. It is well established that those who argue for capital punishment are usually people who see themselves as helpless and inadequate in a changing, complex world, and subconsciously such people see capital punishment as a way of striking back at a confusing world.
Industrial pollution is not harming our environment. Pollution control devices are very expensive, and they raise the prices American consumers pay for manufactured products. Also, if American industry must spend money on pollution control, that will make American industrial products more costly, and will thus make it more difficult for American-made products to compete in the international market. Therefore, our environment is not being damaged by industrial pollution.
It is sometimes claimed that an artist who creates a model for a sculpture and then has someone else actually do the sculpting is still really the artist: like a composer who writes a symphony and then has an orchestra perform it. The composer doesn’t play the instruments, but is still the artist; and in a similar way, some people claim, the artist who creates the model doesn’t actually use a hammer and chisel, but she is still the artist. But that’s not a good comparison, because sculptors work with solid materials like marble or steel and composers work with sounds.
We should not abolish capital punishment because we have had capital punishment in this country since the Colonial period. Even in the early days of Western expansion, the death penalty was imposed. In short, we have had capital punishment in the American colonies and the American nation for some 300 years, and we should not change now.
If Rachel is guilty of first-degree murder, then she must have intended to kill Ralph. And indeed she did intend to kill him, as she admitted in her own testimony. Therefore, Rachel is indeed guilty of first-degree murder. We should not place any waiting period requirement on the purchase of handguns. For if you first start with a required waiting period for handguns, then soon other restrictions on handguns will occur, and then the ban of handguns, and before too long there would be a ban on all private ownership of firearms—and you wouldn’t even be able to own a shotgun for hunting or skeet shooting. “18,812,563 customers can’t be wrong.” Worldwide Auto Parts (billboard advertisement).
129. Rachel argues that it is wrong for humans to eat animals for food since meat-eating is a luxury and not a necessity for humans, and because such indulgence in luxury cannot justify the suffering imposed on the slaughtered animals. But Rachel is wearing leather shoes, a leather belt, and carrying a matching leather handbag: all luxuries, not necessities; and they are all made from slaughtered animals. So Rachel’s arguments against eating meat are undermined by her own actions.
Look, it’s not at all fair for you guys to raise my insurance rates; after all, I’m a very safe and cautious driver. OK, it’s true that I was responsible for four small traffic accidents during the last 2 years, and have received several tickets for reckless driving. But all those things happened when I wasn’t really driving: I was distracted by something, or I was daydreaming or talking on my cellular phone. So those don’t really count as driving.
So when I drive, I am always a very safe and cautious driver. Look, we were faced with a tough choice. Either we carry out a full-scale military attack on Iraq and occupy the country, or we allow Saddam Hussein to build nuclear weapons, biological weapons, and any other weapons of mass destruction that he pleases. But of course we could not allow Saddam to build such weapons of mass destruction. That would have posed a threat to the United States, and also would have destabilized the Middle East. So we were forced to launch a military attack against Iraq.
Some people suggest that chimpanzees have higher intelligence: that they can make plans, solve problems, and even use language. But clearly chimps do not have higher intelligence, because humans are the only animals that have higher intelligence.