LOGICAL FALLACIES Flashcards
AD HOMINEM
def - attacking the individual instead of the argument.
ex. Green Peace’s strategies aren’t effective because they are all dirty, lazy hippies.
ex. You don’t know what you’re talking about, you’ve only lived here for 6 months.
AD IGNORANTIUM
def - asserts that a proposition is true because it has not yet been proven false (or vice versa)
ex. The DA in the OJ Simpson case did not have enough evidence to convict him. A jury found him not guilty, so he must be innocent.
ex. God must exist, since no one can demonstrated that he does not exist.
AD POPULUM (bandwagon)
def - urging the hearer to accept a position because a majority of people hold to it. Popular acceptance proves it is the best one. After all, 85% of people may once have thought planet earth was flat, but that majority’s belief didn’t mean the earth really was flat when they believed it.
ex. The majority of people like soda. Therefore, soda is good.
ex. 85% of consumers purchase IBM computers rather than Macintosh; all those people can’t be wrong. IBM must make the best computer.
ex. Typical ways to express this fallacy will be familiar to anyone who watches television commercials: “the most widely sold…” or “America’s favorite…”
BEGGING THE QUESTION
def - assuming the thing to be true that you are trying to prove. It is circular.
def 2 - when an argument’s premises assume the truth of the conclusion, instead of supporting it.
ex. George Bush is a good communicator because he speaks effectively.
ex. God exists because the Bible says so. The Bible is inspired. Therefore, we know that God exists.
ex. I am a good worker because Frank says so. How can we trust Frank? Simple: I will vouch for him.
RED HERRING
def - a red herring is a deliberate attempt to change the subject or divert the argument from the real question at issue to some side-point.
ex. “I should not pay a fine for reckless driving. There are many other people on the street who are dangerous criminals and rapists, and the police should be chasing them, not harassing a decent tax-paying citizen like me.” Certainly, worse criminals do exist, but that is another issue. The questions at hand are (1) did the speaker drive recklessly, and (2) should he pay a fine for it?
ex. “We can’t raise salaries, but we still provide great benefits for our employees.”
SLIPPERY SLOPE
def - this is a logical fallacy in which the speaker argues that, once the first step is undertaken, a second or third step will inevitably follow, much like the way one step on a slippery incline will cause a person to fall and slide all the way to the bottom. This is a conclusion based on the premise that if A happens, then eventually through a series of small steps, through B, C, …, X, Y, and Z will happen, too, basically equating A and Z. So, if we don’t want Z to occur, A must not be allowed to occur either.
ex. If we ban Hummers because they are bad for the environment, eventually the government will ban all cars, so we should not ban Hummers.
ex. Jason is stressed because he has a calculus test tomorrow and he doesn’t feel prepared. He’s worried that if he doesn’t get an A in calculus, he won’t get the GPA he needs to get into a top school, and then he won’t be able to find a job or earn a living.
HASTY GENERALIZATION
def - Mistaken use of inductive reasoning when there are TOO FEW SAMPLES TO PROVE A POINT. In other words, you are rushing to a conclusion before you have enough evidence.
ex. Drew failed Biology 101. Emelia failed Biology 101. Isabella failed Biology 101. Therefore, I conclude that most students who take Biology 101 will fail it.
(In reality, maybe Drew, Emelia, and Isabella are exceptionally poor students. May they were sick and missed too many lectures that term to pass.
ex. Even though it’s the first day, I can tell this is going to be a boring course.
POST HOC
def - this is a conclusion that assumes that if ‘A’ occurred after ‘B’ then ‘B’ must have caused ‘A’.
ex. “A black cat crossed my path at noon. An hour, my mother had a heart-attack. Because the first event occurred earlier, it must have caused the bad luck later.”
ex. Our soccer team was losing until I bought new shoes. We have not lost a game since I got my lucky shoes!
EITHER/OR
There is a conclusion that oversimplifies the argument by reducing it to only two sides or choices, when there are many gray areas in the center of an argument.
ex. “You could either pursue your dream job or stay where you are and be miserable for the rest of your life.”
ex. We can stop using cars or destroy the earth.
AD ANTIQUATUM
def - things have always been done a certain way, so they should never be reevaluated.
ex. Franklin has kept its urban growth boundary at six miles for the past thirty years. That has been good enough for thirty years, so why should we change it now? If it ain’t broke, don’t fix it.”
ex. Church should begin at 11am because that’s the time that we have always begun the church service. ·
STRAW MAN
an attempt to “prove” an argument by overstating, exaggerating, or over-simplifying the arguments of the opposing side. The name comes from the idea of a boxer who meticulously builds a false opponent out of straw, like a scarecrow, and then easily knocks it over in the ring. His “victory” is a hollow mockery because the straw-stuffed opponent is not the “real” opponent. When a writer makes this opposing argument, he ignores the real points and knocks down each “fake” point one-by-one.
(Occurs when a person rebuts an argument by misconstructing it)
ex. A parent doesn’t let their daughter go to a party. The daughter responds with “Why do you hate me?”
ex. The boyfriend tells his girlfriend that he doesn’t want to go out to eat tonight. The girlfriend rolls her eyes and tells him he never wants to go out anymore.
ex. Starbucks decides to write “Happy Holidays” on their cups instead of “Merry Christmas”. The media is outraged, accusing Starbucks of waging a war on Christmas.
GENETIC FALLACY
def - irrelevance where a conclusion is suggested based solely on someone’s or something’s history, origin, or source rather than its current meaning or context.
ex. My mommy told me that the tooth fairy is real. Therefore, the tooth fairy is real.
ex. Eugenics was pioneered in Germany during the war. Therefore, Eugenics is a bad thing.
NON-SEQUITUR
a statement (such as a response) that does not follow logically from or is not clearly related to anything previously said.
ex. We were talking about the new restaurant when she threw in some non sequitur about her dog.
ex. “All trees are tall, all tall things are yellow, therefore, all trees are green.”
Plants need water to grow. I will water this rock and it too will grow.
