Logical Fallacies
Definition Logical fallacies are flaws or gaps in logic that undermine an argument. You should, of course avoid using logical fallacies in your own writing; you should also look for these when you’re critically reading as well. There are many different types, but we’ll go over those that are most commonly used.
Hasty generalization A hasty generalization is a conclusion based on insufficient evidence. Many stereotypes, for example, are hasty generalizations. Asian students are exceptionally intelligent. Stereotyping is prevalent since we, as humans, like to categorize and group people. We also tend to see evidence that confirms our previously held beliefs. Many hasty generalizations contain words like “all,” “ever,” “always,” or “never”. Qualifiers like “most,” “many” or “seldom,” can increase accuracy and help you avoid making a hasty generalization
Faulty Analogy An analogy points out similarities between things that are otherwise different. They can be effective when handled correctly. However, the analogy can become faulty when there is an assumption that the two items are comparable when if fact they are not. If we can put humans on the moon, we should be able to find a cure for the common cold. Putting humans on the moon and finding a cure for the common cold are both scientific endeavors, but the problems confronting medical researchers and space scientists are quite different.
Faulty Cause When two events occur silumtaneously orone after another, we tend to see causal relationships between them: one caused the other. However, there could be a third, unnamed cause contributing to the outcome. Therefore, explaining a causal relationship is difficult and should be approached with care. The chemistry course had a high failure rate. Therefore, the professor was ineffective. What other causes might be contributing? Large class size Inadequate preparation of students Lack of support resources like tutors on campus
Either-Or Fallacy When we boil down a situation so that there appear to be only two options when in reality there are more, we have used the either or fallacy. Either you support the President in everything he says and does or you are not a patriotic American.
Non sequitur Claims are backed by reasons. When the relationship is between the claim and the reason is unclear, a non sequitur fallacy has been committed. Non sequitur is Latin for “does not follow” Mary loves good food; therefore, she will be an excellent chef. How will enjoying food qualify her to be a chef? What qualities do make people good chefs?
Straw Man A straw man fallacy sets up the counter argument so that it is easy to tear down, a misrepresentation of the opposition. People who think abortion should be banned have no respect for the rights of women. They treat them as nothing but baby-making machines. That's wrong. Women must have the right to choose.
Appeal to tradition Explaining that we’ve followed a procedure for a long time is not enough justification for continuing that procedure. The appeal to tradition was a common defense of slavery prior to the Civil War. People in the South explained that they knew no other way of life, and therefore the practice had to continue.
Bandwagon The bandwagon fallacy is the assumption that just because something is popular, it is good/right/acceptable. If all of your friends jumped off a cliff, would you do it, too?
False authority When doing research, citing relevant experts in the field is key in establishing your ethos and logos. If you cite an expert whose expertise is in an unrelated field, you have used the false authority analogy. My friend, who is serving in the infantry in Iraq, tells me that the government has a secret plan for how to win the War that they won’t release until after the election
Ad hominem When addressing the counter argument, it is important to keep criticism relevant to the presentation of ideas rather than attacking people personally. “Ad Hominem” is Latin for “to the man”. It is a personal attack. Here’s what I think about what you have written: anyone who opposes the death penalty for murder is a criminal at heart.
Circular Reasoning When supporting a claim, you need to give reasons and evidence to back it up. Circular reasoning happens when, rather than giving reasons to support your claim, you re-state your claim in new words. Wrestling is a dangerous sport because you can get hurt while doing it.
Guilt By association Arguing that all members of a group are like some other members of that group, or are responsible for what those others have done. Those who attacked the United States on September 11, 2001 were Muslims; therefore, all Muslims are potential terrorist threats to the United States.
Slippery slope To greatly exaggerate the supposedly inevitable future consequences of an action by suggesting one small step will initiate a process that will necessarily lead the way to a much bigger result. If you restrict my right to say whatever I want anywhere I want however I want, this is the beginning of totalitarianism in America.
Red Herring Drawing attention away from the issue at hand by focusing on an irrelevant issue as a substitute for making a case. You can’t trust Jim to do a good job as student body president; he doesn’t dress with an up-to- date sense of style.
Activity Read through Rush Limbaugh’s article “Sexual Harassment and the Feminist Front” Look for logical fallacies as you read. See if you can identify and label them by type. Now get into small groups of about 3 or 4 and share your findings. Be prepared to share your findings with the rest of the class.