Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Transcript of Logical Fallacies
Slippery Slope and Flawed Analogy
Based on the idea that if one event is allowed to occur, it will be followed by other negative events.
Example: "America shouldn't get its military involved in Syria, because then we will have to get involved in every conflict."
Example 2: "If we don't stop allowing domestic spying now, eventually, we'll never be in private!"
Slippery slope is partly based on a flawed analogy.
A flawed analogy is a statement that sets up an equivalence where none exists.
Example: "Education is like business, so we should use the ideas of successful businesses to apply to educational institutions."
Hasty Generalization & Genetic Fallacy
A conclusion based on insufficient or biased evidence.
Example: "I knew a girl who said that all men were sexist pigs. She said she was a feminist. All feminists must hate men."
Example 2: "You can never trust a man."
The hasty generalization is related to the genetic fallacy.
Genetic fallacies are those which use the source of an idea, person, institution, etc., as the primary determiner of its worth or character.
Example: "We shouldn't ban smoking in restaurants, because the Nazis banned smoking in restaurants."
Post Hoc Ergo Propter Hoc
Roughly translated, "after this, therefore because of this," it can also be called "correlation, not causation."
This fallacy assumes that if Second Event follows First Event, that First Event must have *caused* Second Event.
Example: "I wore my new shoes, and then I won the race. Therefore, my new shoes must be lucky!"
Begging the Claim/Question and Circular Argument
Begging the claim uses language within the claim to validate the proposal.
Example: "If it's a Hollywood blockbuster, it has to be good, because they wouldn't have made it if it wasn't."
Circular arguments rephrase the argument rather than proving it.
Example: "You can't give me a C! I'm an A student."
Begging the claim and circular arguments are related partly in terms of *language*.
Red Herring Fallacies
The classic "red herring" is when one responds to an argument with another argument that is irrelevant and draws attention away from the first argument.
Example: A mother warns her teen son against drinking at a party. He replies "Mom, how can you even think of that when I've been studying all day?"
"Red herring" introduces irrelevant information into an argument in order to mislead.
"Reductio ad Absurdum" is related to a red herring.
The "thought-terminating cliche'" is another version.
Example: "Everything happens for a reason."
Example 2: "That's just your feelings."
Ad Hominem and Straw Man
"Ad hominem," or "to the man" is an attack on the character of the person rather than on the argument.
Example: "'No Child Left Behind' is bad educational policy because George W. Bush was stupid."
Example 2: "I don't care what Greenpeace has to say, because they're just a bunch of dirty hippies."
A straw man is when the weakest version of an opposing argument is set up in order to be knocked down.
Example: "Atheists believe in nothing and so, can't be moral."
Example 2: "Christians blindly accept whatever their pastors tell them, and so are easy to lie to."
Appeals to Credibility and Emotion
Both pathos and ethos can be used in fallacious ways.
Appeals to credibility can be manipulated. For example, ads and fake news may use celebrities rather than *relevant*experts.
Emotional appeals can also be manipulated, particularly if the author is over-reliant on them. There are many types of emotional appeals, and it is important to distinguish between them (pity, fear, ridicule, flattery).
Naturalistic Fallacy/Moralistic Fallacy
supposes that what is found in nature is *good*.
Example: "War is good because violence is instinctive."
Example 2: "Nature gives people diseases and sickness; therefore, it is morally wrong to interfere with nature and treat sick people with medicine."
supposes that what is good found in nature.
Example: "Being mean to others is wrong. Therefore, it cannot possibly be part of our nature."
Example 2: "Because everybody ought to be treated equally, there are no differences between people."
Either/Or (False Dilemma)
Holding out two possible options as if they are the only choices, but there are in fact more.
Example: "Either you're with us, or you're with the terrorists."
Example 2: "You're either a vegan, or you hate animals."
A related fallacy is the argument from ignorance, which assumes that a claim is false because it has not been proven true, or that a claim is true because it has not been proven false.
Example: "Since there is no evidence that Big Foot exists, he must not be real."
As mentioned on the OWL page, logical fallacies are *common* flaws in reasoning that undermine your argument.
An argument can contain *formal* logical fallacies whether or not it is based on the truth.
An *informal* fallacy is fallacious because its content is somehow unreasonable.
Tu Quoque, and the Fallacy of Relative Privation
Tu quoque is a fallacy that points out hypocrisy.
Example: "Jimmy Swaggart argued strongly against sexual immorality, yet he has had several affairs with prostitutes, therefore, sexual immorality is acceptable."
Tu quoque is also related to the "Two wrongs make a right" fallacy.
The fallacy of relative privation suggests that an argument should be ignored because there are other, often unrelated, problems in the world.
Example: "Eat your dinner, because there are children starving in Africa!"
Post Hoc Ergo Propter Hoc