LOGICAL FALLACIES Informal Reasoning

 A fallacy is a failure in reasoning that leads to an argument being invalid.  They are like cracks in the foundation of a building;; if they are present, the building is going to fall down. FALLACY

WHY SHOULD WE LEARN FALLACIES?  Detecting fallacies is a very important part of making yourself critically skilled.  If you know what fallacies are, you can… Avoid making them yourself when you present an argument. Spot them when others are using them.

WHO USES FALLACIES?  Everyone… at times.  Some are present innocently.  Some are done deliberately. Advertising Politics Media Law

1.Hasty generalization 2.Post hoc ergo propter hoc 3.Ad hominem fallacy 4.Circular reasoning 5.Special pleading 10 LOGICAL FALLACIES 6.Equivocation 7.Argument ad ignorantiam 8.False analogy 9.False dilemma 10.Loaded questions

HASTY GENERALIZATION  Generalizing from not enough evidence  Stereotyping Example: He’s Mexican so he must know how to garden.

POST HOC ERGO PROPTER HOC  An immediate jump to a conclusion without enough or very little evidence.  Something is not the cause of something else just because they follow each other. Example: People who drink one glass of wine a day have a lower chance of heart disease.

AD HOMINEM FALLACY  Rejecting what someone says solely on the basis of whom they are or what they believe.  Attacking or critiquing the person instead of critiquing the argument or point made. Example: President Wilson supported the League of Nations so it must be a good thing.

CIRCULAR REASONING  Vicious circle: One negative action/idea or wrong way of thinking leads to another.  Just assuming something is true when you are supposed to be proving it. I know that Sandra is innocent because Sandra would not lie to me.

SPECIAL PLEADING  Just because you are in a crisis, you believe that you deserve “the second chance”.  Having “Double Standards”… Do as I say, not as I do. Example: The city has asked residents to conserve water, everyone is expected to limit things such as showers but you make an exception for yourself… after all you hair is long and thick.

EQUIVOCATION  A term used in two or more senses with a single argument.  Comparing two like things that are not really alike or language is ambiguous or unclear. Example: A hamburger is better than nothing; nothing is better than good health; therefore, a hamburger is good health.

ARGUMENT AD IGNORANTIAM  To claim that something is true on the grounds that there is no evidence to dispute it. Example: I believe zombies exist because no one can prove they don’t. Example: I believe God exists because no one can prove that he doesn’t.

FALSE ANALOGY  Just because two things are similar in some situations does not mean they are in all situations. Example: Just as in time the gentle rain can wear down the tallest mountains, so, in human life, all problems can be solved by patience and quiet persistence.

FALSE DILEMMA  Assuming only two black and white dilemmas exist or divide things into two types.  When you leave little option or only two options- when in reality, things are rarely so simple. Example: Do people who want to see an increase in military spending really want to see our schools close? (This makes it sound like tax money either goes entirely to military or entirely to education.)

LOADED QUESTION  To put an assumption in a question.  A question with a false, disputed, or question-begging presupposition. Example: Do you always cheat on tests? It is assuming that you have cheated on tests at some point in time.