Exam 3: Informal Fallacies

Either the Nile or the Amazon is the longest river. But the Amazon is not the longest river. Therefore, the Nile is the longest river.

Rich people tend to be snobs because they have materialistic values. Of course they have materialistic values because they fail to appreciate true human qualities. And why do they do this? Because they are condescending and haughty. Naturally they are condescending and haughty because they tend to be snobs.

Every player on the varsity chess team is very good. Therefore, the team is very good.

Senator Dawson argues in favor of legalizing marijuana. But did you know that the senator has been married three times? And his last divorce was a real doozie. His wife went on and on about their sex life. Apparently the Senator is no good in bed. Enough about that issue ... . Shall we move on?

Willie the Weasel could not possibly be responsible for burglarizing the jewelry store. Willie is an inept bungler who couldn't steal a newspaper from a broken vending machine.

Every patch in this patchwork quilt is some shade of green. Therefore, the entire quilt is green.

The speed limit in this neighborhood is 25 miles per hour. Therefore, it was illegal for that ambulance to drive through here at 50 miles per hour.

Protons are not combustible, and neither are electrons. It therefore follows that hydrogen, which is composed of protons and electrons, is not combustible.

The number of alcoholics has risen steadily for the past 20 years, and so has the number of treatment centers. Therefore, to cut down on alcoholism we should eliminate the treatment centers.

The use of marijuana for medical purposes should never be allowed. Before long it will be marijuana for anyone who wants it. Then it will be hash, cocaine, and crack. In no time they'll want crystal, ecstasy, and heroin. In the end everyone will be so drugged out they won't be able to see straight.

The use of contraceptives is immoral, because anything that violates nature is immoral.

Joe Bradley has thick calluses on both of his hands. Thus, it would appear that Joe does a lot of manual labor.

Either Jane Austen was English or she was American. Since Jane Austen was not American, it follows that she was English.

Floyd Conway has given us his reasons for unrestricted logging in our national forests. But it's obvious why he says these things. Floyd is a lumberjack, and he just wants to ensure that he'll have a job in the years ahead.

Mr. Thompson, our jeweler, says that the stone in your ring is a sapphire. Since Mr. Thompson has an excellent reputation among jewelers, we conclude that the stone is indeed a sapphire.

It's appropriate for parents to invade their children's privacy to protect them from danger. But the role of government is similar to that of parents. Therefore, it's appropriate for the government to invade the privacy of citizens to protect the country.

Nobody has ever seen Mr. Albie walk without crutches. We conclude that Mr. Albie needs crutches to walk.

Benjamin Franklin wrote, "Beer is proof that God loves us and wants us to be happy." Therefore, since old Ben would never lie about anything so important as God, we must conclude that God does indeed exist.

Smith, Adams, and Harris all outlived their wives, and their wives were younger than they were. It must be the case that men outlive women these days.

Either Coleridge or Longfellow wrote the "Rime of the Ancient Mariner." But it certainly wasn't Longfellow. Therefore, Coleridge wrote it.