Clear Thinking: Logical Fallacies

Logical Fallacies Overgeneralization – coming to a conclusion based upon too few examples * “I took one class at Mentone Junior College and it was terrible – I’ll never take classes there again.” 2. Post Hoc/Cause-Effect (aka False Cause) – assuming that because A happened before B that A is the cause of B. “My car didn’t have any problems before I took it in for a tune-up; once I got it home, the fan belt broke – those mechanics must’ve arranged that so they could make more money off of me.” John is scratched by a cat while visiting a friend. Two days later he develops a fever and concludes the cat scratch is the cause of the illnes.

Logical Fallacies False Analogy – attempting to argue by comparison when the comparison seeks to make similar two things that really aren’t similar in essential ways. Ex: "Education is like cake; a small amount of cake tastes sweet, but eat too much and your teeth will rot out. Likewise, more than two years of education is bad for a student."

Logical Fallacies Ad hominem – attacking the arguer instead of the argument/issue under consideration * “You only support universal health care because you’re a Communist.” 5. Rationalizing – giving plausible but untrue reasons for our behavior *Me: John, sit down. John: I’m just getting a pencil. *Hospital patient dies due to physician error: “Why disclose the error? The patient was going to die anyway.”

Logical Fallacies Circular Thinking – “arguing in a circle” – restating the initial claim repeatedly without actually explaining WHY the statement is correct. “I can’t stand Mr. Martin’s class because I’m never happy in there.” God exists because the Bible says so; the Bible is true because it was written by God. 7. Begging the Question – assuming to be true the very issue that is being debated *Interviewer: "Your resume looks impressive but I need another reference.“ Bill: "Jill can give me a good reference.“ Interviewer: "Good. But how do I know that Jill is trustworthy?“ Bill: "Certainly. I can vouch for her." *Abortion is wrong because it’s murder.

Logical Fallacies Either-Or (aka False Dilemma, “Black & White”) – oversimplifying an issue into only two choices, when there may actually be more options to consider * "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." *Either we ban guns and keep our children safe or we allow free access to guns and we will be in constant danger or another massacre.

Logical Fallacies Bandwagon Appeal – “Everybody is doing it.” If a majority of people do/believe something, then it must be correct/true. Common tactic used in peer pressure and commercials. * “Mom, everybody else at school has a phone – why can’t I have one too?” *"Since Redlands High, REV, and Beaumont High all have open campuses, YHS should do the same.“

Logical Fallacies – Appeal To Tradition (aka Argument from Antiquity) – the belief that if something is well-established and proven it is correct/right and should be maintained * “My father and his father before him polished wood this way. Don't tell me how to polish wood.” 11. Appeal to Novelty – the belief that because something is new, it is superior to what is old. *This year's model has twenty new features.

Logical Fallacies – Appeal to Authority – the attempt to demonstrate the truth of a matter by citing some famous person who may or may not actually have any expertise in a matter. (only a fallacy if the cited person isn’t an expert). * “Stephen Hawking has concluded that black holes give off radiation.” (appropriate use of appeal to authority) * “Taylor Swift says that Firestone tires are the highest quality tires I can buy.” (inappropriate use of appeal to authority)

Logical Fallacies – Appeal to Pity (aka Special Pleading) – the attempt to get a conclusion accepted based upon feelings of pity * “I did not murder my mother and father with an axe. Please don't find me guilty; I'm suffering enough through being an orphan.” * “I haven't completed my work because my dog just died.”

Logical Fallacies – Slippery Slope Argument - The assumption that one event can cause of an undesirable chain reaction of events. The slippery slope fallacy is a case of if-then (“if you do A, then B,C, and D will follow”). Note: the slippery slope argument is only a fallacy when there is no clearly established cause-effect chain present between the initial act and the assumed following acts. *“If we allow the government to take away our automatic assault rifles, than they will take away all of our guns and we won’t be able to hunt or shoot recreationally.”

Logical Fallacies – Straw Man - attempt to "prove" an argument by over-stating, exaggerating, or over- simplifying the arguments of the opposing side *People who believe we should spend less for defense apparently believe no one will ever attack us. * “Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why he wants to leave us defenseless like that.”