Logical-Fallacies-and Appeals

LOGIC VOCAB

• Premise: Proposition used as evidence in an argument.• Conclusion: Logical result of the relationship between the

premises. Conclusions serve as the thesis of the argument. • Argument: The assertion of a conclusion based on logical

premises.• Syllogism: The simplest sequence of logical premises and

conclusions, devised by Aristotle.• Enthymeme: A shortened syllogism which omits the first

premise, allowing the audience to fill it in. For example, "Socrates is mortal because he is a human" is an enthymeme which leaves out the premise "All humans are mortal."

• Induction: A process through which the premises provide some basis for the conclusion.

• Deduction: A process through which the premises provide conclusive proof for the conclusion.

DOES LOGIC ALWAYS WORK?

• Logic is a very effective tool for persuading an audience about the accuracy of an argument. However, people are not always persuaded by logic. Sometimes audiences are not persuaded because they have used values or emotions instead of logic to reach conclusions. But just as often, audiences have reached a different logical conclusion by using different premises. Therefore, arguments must often spend as much time convincing audiences of the legitimacy of the premises as the legitimacy of the conclusions.

So how do I find fallacies in my own writing?

• Here are some general tips for finding fallacies in your own arguments:

• Pretend you disagree with the conclusion you’re defending. What parts of the argument would now seem fishy to you? What parts would seem easiest to attack? Give special attention to strengthening those parts.

• List your main points; under each one, list the evidence you have for it. Seeing your claims and evidence laid out this way may make you realize that you have no good evidence for a particular claim, or it may help you look more critically at the evidence you’re using.

So how do I find fallacies in my own writing?

• Learn which types of fallacies you’re especially prone to, and be careful to check for them in your work. Some writers make lots of appeals to authority; others are more likely to rely on weak analogies or set up straw men. Read over some of your old papers to see if there’s a particular kind of fallacy you need to watch out for.

• Be aware that broad claims need more proof than narrow ones. Claims that use sweeping words like “all,” “no,” “none,” “every,” “always,” “never,” “no one,” and “everyone” are sometimes appropriate—but they require a lot more proof than less-sweeping claims that use words like “some,” “many,” “few,” “sometimes,” “usually,” and so forth.

• Double check your characterizations of others, especially your opponents, to be sure they are accurate and fair.

Rhetorical AppealsoEthos, Pathos, and most importantly

Logos•Ethos - ethics or ethical. Better known as

“image”•Pathos - the emotion of the audience•Logos – logic of the argument.

▫ Persuasion, to a large extent, involves convincing people to accept our assumptions as probably true. Similarly, exposing questionable assumptions in someone else's argument is an effective means for preparing the audience to accept your own contrary position

LETS PLAY A

GAME

a. slippery slopeb. black-or-whitec. bandwagond. false cause

Example: Pointing to a fancy chart, Roger shows how temperatures have been rising over the past few centuries, whilst at the same time the numbers of pirates have been decreasing; thus pirates cool the world and global warming is a hoax.

a. ambiguityb. appeal to pityc. burden of proofd. slippery slope

Example: The fallacy of urging an audience to “root for the underdog” regardless of the issues at hand. “Those poor, cute little squeaky mice are being gobbled up by mean, nasty cats that are ten times their size!”

a. black-or-whiteb. ad hominemc. slippery sloped. burden of proof

Example: Colin Closet asserts that if we allow same-sex couples to marry, then the next thing we know we'll be allowing people to marry their parents, their cars and even monkeys.

a. bandwagonb. ad hominemc. burden of proofd. composition/division

Example: After Sally presents an eloquent and compelling case for a more equitable taxation system, Sam asks the audience whether we should believe anything from a woman who isn't married, was once arrested, and smells a bit weird.

a. black-or-whiteb. composition/divisionc. ambiguityd. burden of proof

•Example: Bertrand declares that a teapot is, at this very moment, in orbit around the Sun between the Earth and Mars, and that because no one can prove him wrong, his claim is therefore a valid one.

a. ambiguityb. black-or-whitec. begging the question(circular reasoning)d. bandwagon

•Example: The witchcraft problem is the most urgent challenge in the world today. Why? Because witches threaten our very souls

a. non sequiturb. bandwagonc. composition/divisiond. ambiguity

•Example: The fallacy of offering reasons or conclusions that have no logical connection to the argument at hand (e.g. “The reason I flunked your course is because the government is now putting out purple five-dollar bills!”)

a. red herringb. composition/divisionc. black-or-whited. false cause

• Example: An irrelevant distraction, attempting to mislead an audience by bringing up an unrelated, but usually emotionally loaded issue. E.g., "In regard to my recent indictment for corruption, let’s talk about what’s really important instead--terrorists are out there, and if we don't  stop them we're all gonna die!"  

a. straw manb. bandwagon c. black-or-whited. slippery slope

•Example: Whilst rallying support for his plan to fundamentally undermine citizens' rights, the Supreme Leader told the people they were either on his side, or they were on the side of the enemy.

a. bandwagon b. slippery slope c. false cause d. ad hominem

•Example:  The fallacy of attempting to refute an argument by attacking the opposition’s personal character or reputation, using a corrupted negative argument from ethos. "He's so evil that you can't believe anything he says."

•THE END