Exam 3: Informal Fallacies

Nobody has ever proved that Ouija boards can't be used to predict the future. It therefore follows that they can be used for this purpose.

This cup of coffee contains caffeine. Therefore, every spoonful of it contains caffeine.

Which of the following fallacies arises from a statement made by someone other than the arguer?

Professor Stevens, the great English scholar, says that Chaucer's Canterbury Tales represents a milestone in the development of the English language. Therefore, the Canterbury Tales must indeed be a milestone, just as he says.

For the past several years, every time that Ruben has suffered a bout of sneezing, he has come down with a cold. Therefore, to prevent colds in the future, Ruben must constantly suppress the urge to sneeze.

George likes chocolate truffles, and he also likes Tabasco sauce. Therefore he would certainly like some chocolate truffles topped with Tabasco sauce.

Given the argument, "If the sky is clear, then the stars are visible. The stars are visible. Therefore, the sky is clear." This argument is an example of:

This pamphlet from the hospital says I should eat right before surgery. Apparently I should go into the operating room with a full stomach.

Karen argues that it's not right to post the photographs of convicted child molesters on the Internet. Obviously Karen supports child molestation. But these monsters have completely ruined the lives of thousands of children. They can't be allowed to wreak their havoc any longer. Clearly, Karen's argument is misguided.

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.

A fallacy that can be detected through mere inspection of the form of an argument is:

Either you pay my tuition to Stanford or I'll be doomed to a life of mediocrity. I'm sure you don't want that.

Professional sports figures are not the clean, upright types people take them to be. Just look at Tiger Woods. He betrayed his lovely wife by engaging in extramarital affairs with several different women.

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.

There is a good deal of concern these days about whether eating fast food is unhealthy. But most fast food is really tasty. Just think of those juicy McDonald's hamburgers dripping with melted cheese, and the wonderful golden fries. And the crispy Chicken McNuggets, the creamy shakes, and the Egg McMuffins. How could anyone complain about today's fast food?

By accident Shelley left her old fashioned flashlight turned on all night. Therefore, it's likely that the batteries are dead.

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.

The first rule of good behavior is always be yourself. Therefore, professional actors, who adopt the role of someone other than themselves, are behaving improperly.

Every ingredient in this new drink concoction is highly alcoholic. Therefore, the drink is highly alcoholic.