Logical Fallacies - Comp 2 The Fallacy A fallacy is simply an error in logic. Put another way, a fallacy is a flaw in reasoning that can seriously undermine an argument. The following are some of the most prevalent and well-known fallacies.

Logical Fallacies - Comp 2 Emotive Language Fallacies that fall under the category of emotive language include appeals to fear, pity, flattery, and peer pressure. e.g. – “Without the Second Amendment which guarantees our right to have guns, the government is going to take away all our guns, and then we and our children will be at the mercy of rapists, murderers and thieves.”

Emotive Language e.g. – “The Segway is an amazing breakthrough in transportation technology! This amazing device will revolutionize the way we travel!”

Emotive Language

Straw Man When the arguments of the opposition are distorted or exaggerated, we end up with a “straw man” that is easily knocked down. e.g. – “We should have the draft reinstated. The whole thing is that people don't want to enter the military because they find it an inconvenience. But they should realize that there are more important things than convenience.”

Straw Man e.g. - “All the people who are in favor of cloning want to do is bring back loved ones who have died. That’s playing at God and not realistic, so we should not consider cloning a reasonable idea.”

Straw Man

Ad hominem From the Latin phrase “to the man” this fallacy uses a personal attack on an individual as a substitute for a reasoned critique of the individual’s position. e.g. – “Governor Romney came up with a plan to help poor people, but why bother with it? He’s never been poor. What would he know about helping the impoverished?”

Ad hominem Bill: "I believe that abortion is morally wrong." Dave: "Of course you would say that, you're a priest." Bill: "What about the arguments I gave to support my position?" Dave: "Those don't count. Like I said, you're a priest, so you have to say that abortion is wrong. Further, you are just a lackey to the Pope, so I can't believe what you say."

Ad hominem

False Dilemma (Either-or) Sometimes called the “either-or” fallacy, this describes the strategy of presenting only two extreme alternatives and leaving out any middle ground. e.g. – “America – love it or leave it.”

False Dilemma e.g. - "Look, you are going to have to make up your mind. Either you decide that you can afford this stereo, or you decide you are going to do without music for a while."

False Dilemma

Post Hoc Ergo Propter Hoc – (Post Hoc) Sometimes called “false” cause reasoning, this fallacy takes its name from the Latin phrase post hoc ergo propter hoc which means “after this, therefore because of this.” It is assumed there is a cause and effect relationship between two events simply because one came first. e.g. – “Soon after she got married she started drinking a great deal. Her heavy drinking must have been caused by her marriage.”

Post Hoc Ergo Propter Hoc – (Post Hoc) e.g. – “Our school instituted a dress code policy and there was a decrease in vandalism. Therefore, we should keep the dress code because it caused the drop in vandalism.” Other factors may be at work such as increased security, more troublesome students being expelled, etc.

Post Hoc Ergo Propter Hoc – (Post Hoc)

Slippery Slope This fallacy suggests that if one thing happens, something else will necessarily follow. Sometimes it is also called the “domino theory.” e.g. – “You should never gamble. Once you start gambling you find it hard to stop. Soon you are spending all your money on gambling, and eventually you will turn to crime to support your earnings.”

Slippery Slope e.g. - If we pass laws against fully-automatic weapons, then it won't be long before we pass laws on all weapons, and then we will begin to restrict other rights, and finally we will end up living in a communist state. Thus, we should not ban fully-automatic weapons.

Slippery Slope

Circular Reasoning Sometimes called “begging the question” the justification of the claim is simply a restatement of the claim. e.g. - "The stock market fell because of a technical downward adjustment."

Circular Reasoning

Common practice - Here the appeal is to popular behavior. Sometimes called “bandwagon” it is the idea that since everyone else is doing it, it is acceptable. It is sometimes called “ad populum.” e.g. – “Everyone takes software off the internet without paying for it. It’s okay.”

Common practice e.g. - Everyone is selfish; everyone is doing what he believes will make himself happier. The recognition of that can take most of the sting out of accusations that you're being 'selfish.' Why should you feel guilty for seeking your own happiness when that's what everyone else is doing, too?"

Common practice E.g. - “Harry Potter and the Big, Giant Cauldron of Money must be a great book, eight million people have bought it.”

Common practice E.g. – “Most people in the state support the death penalty, so it must be the morally right thing to do.”

Common practice

Red Herring This fallacy is a classic example of distraction – using an unrelated point to distract the audience’s attention from the real issue at hand. e.g. - "I think there is great merit in making the requirements stricter for the graduate students. I recommend that you support it, too. After all, we are in a budget crisis and we do not want our salaries affected."

Red Herring e.g. - "You know, I've begun to think that there is some merit in the Republican's tax cut plan. I suggest that you come up with something like it, because If we Democrats are going to survive as a party, we have got to show that we are as tough-minded as the Republicans, since that is what the public wants."

False Analogy As we know, an analogy is a comparison of two things showing how they have a similarity. A false analogy is a comparison that may seem acceptable on the surface, but in truth, has little or no similarity.

False Analogy E.g.- “Government is like a business; therefore, it must be sensitive to the bottom line.”

False Analogy E.g.- “Students should be allowed to look at their textbooks during an exam. Doctors look at x-rays during an operation, lawyers look at their legal briefs during a trial, so why shouldn’t students get a chance to look at their textbooks?”

Hasty Generalization Making a generalization based on too small a sample. e. g. – A man from England is visiting the United States. He spies two albino squirrels on a tree outside his hotel window. When calling his wife in England, he tells her all the squirrels in the USA are white.

Hasty Generalization e. g. – “I talked to a couple of people in town and they were for the idea of getting rid of the park and putting in a big parking lot. I’m sure most of the people in town feel the same way.”

Non sequitur This phrase comes from the Latin: “it does not follow.” Like the false analogy, the non-sequitur jumps from one point to another without any logical reason. E.g. – “You shouldn’t take Dr. Wilkie’s class because he’s from New Jersey.”

Non sequitur This phrase comes from the Latin: “it does not follow.” Like the false analogy, the non-sequitur jumps from one point to another without any logical reason. E.g. – “You shouldn’t take Dr. Wilkie’s class because he’s from New Jersey.”

Non sequitur