1. Logical Fallacies
ERWC

2. What is a logical fallacy?
Definition: statements that might sound reasonable or superficially true but are actually flawed or dishonest
Tricks, illusions of thought

3. Why are logical fallacies used if they’re wrong?
They can work if the audience isn’t knowledgeable
Unintentional in younger, less experienced thinking/writing

4. Types of Fallacies
Fallacies of Relevance: Evidence that is used is irrelevant to the claim
Fallacies of Accuracy: Evidence is intentionally or unintentionally wrong
Fallacies of Insufficiency: Not enough evidence is provided
Others

5. Slippery Slope
Definition: This is a conclusion based on the idea that if A happens, then B, C…X, Y, Z will happen, too; therefore, A shouldn’t happen.
Effect: shifts attention to extreme hypotheticals instead of the issue at hand
Appeal to pathos (usually fear)

6. Direct TV commercial

8. Slippery Slope Examples
We have to stop the tuition increase! The next thing you know, they'll be charging $40,000 a semester!"
"The US shouldn't get involved militarily in other countries. Once the government sends in a few troops, it will then send in thousands to die."
If we ban Hummers because they are bad for the environment eventually the government will ban all cars, so we should not ban Hummers.

9. Ad hominem
Definition: This is an attack on a person’s character or personal traits rather than his/her opinions or arguments.
Effect: By attacking the person, it casts doubt on their character, thus undermining someone’s case w/o actually having to argue the issue.
Fallacy of Relevance

12. Barack Obama: attacking Sarah Palin saying she’s not an expert rather than addressing the argument

13. Ad hominem Example
Example: Green Peace’s strategies aren’t effective because they are all dirty, lazy hippies.
In this example, the author doesn’t’ even name particular strategies Green Peace has suggested, much less evaluate those strategies on their merits. Instead, the author attacks the characters of the individuals in the group.
This type of logical fallacy is very common in politics.

14. Red Herring
Definition: A remark that is irrelevant or has only surface-level relevance, usually emotionally-loaded.
Effect: mislead and distract an audience from the actual facts.
Fallacy of Relevance

15. Red Herring Example
The level of mercury in seafood may be unsafe, but what will fishers do to support their families?
Mike: It is morally wrong to cheat on your spouse, why on earth would you have done that?
Ken: But what is morality exactly?
Mike: It’s a code of conduct shared by cultures.
Ken: But who creates this code?...
In this example, the author switches the discussion away from the safety of the food and talks instead about an economic issue, the livelihood of those catching fish. While one issue may affect the other, it does not mean we should ignore possible safety issues because of possible economic consequences to a few individuals.

16. Straw Man
Definition: When a speaker chooses a poor or oversimplified version of an argument to make it easier to attack
This is done by exaggerating, misrepresenting, misquoting, leaving out key information, or completely fabricating an argument
Effect: Presents your own position as reasonable in comparison (dishonest)
Fallacy of Accuracy

18. Straw Man

19. Straw Man: she never implied this.

20. Straw Man Example
People who don’t support the proposed state minimum wage increase hate the poor.
Bill and Jill are arguing about cleaning out their closets: Jill: "We should clean out the closets. They are getting a bit messy." Bill: "Why, we just went through those closets last year. Do we have to clean them out everyday?" Jill: "I never said anything about cleaning them out every day. You just want too keep all your junk forever, which is just ridiculous."
In this example, the author attributes the worst possible motive to an opponent’s position. In reality, however, the opposition probably has more complex and sympathetic arguments to support their point. By not addressing those arguments, the author is not treating the opposition with respect or refuting their position.

21. Either/Or Fallacy (AKA False Dilemma)
Definition: Two extreme choices are presented as the only possible choices when in fact more possibilities exist
Effect: appearance of a logical argument
Fallacy of Accuracy
There may several possible choices, but only the extreme choice and/or the choice wanted are presented.

24. Either/Or Fallacy Examples
“Either we agree to higher taxes, or our grandchildren will be mired in debt” (Ausfes et al. 103).
We can either stop using cars or destroy the earth.
In this example, the two choices are presented as the only options, yet the author ignores a range of choices in between such as developing cleaner technology, car-sharing systems for necessities and emergencies, or better community planning to discourage daily driving.

25. Anecdotal Fallacy
Definition: Using personal experience as evidence instead of logos
Effect: It can be enough to the right audience as convincing evidence
Students, be careful about this fallacy being in your writing (inexperience, lack of enough info)
Fallacy of Insufficiency

26. Anecdotal Fallacy Example
Smoking isn’t harmful. My grandfather smoked a pack a day and lived until 97.
Global warming? Yeah, right! It was a record low in my town today.

28. Hasty Generalization
Definition: This is a conclusion based on insufficient evidence. In other words, you are rushing to a conclusion before you have all the relevant facts.
Effect: If you have a conclusion that sounds strong, the untrained audience will be satisfied with this
Fallacy of Insufficiency

30. Fallacies: Part 2

31. Faulty analogy Often used to appeal to pathos
Example: an expensive product is pictured with a famous person and a connection is made between the product’s purpose or qualities and the famous person’s talent(s).
Fallacy of Relevance

32. Evidence is intentionally or unintentionally WRONG
Fallacies of accuracy
Evidence is intentionally or unintentionally WRONG

33. Either/or fallacy (aka false dilemma)
Two extreme choices are presented as the only possible choices
EXAMPLES
“Either we agree to hire taxes, or our grandchildren will be mired in debt” (Ausfes et al. 103).
We can either stop using cars or destroy the earth.
In this example, the two choices are presented as the only options, yet the author ignores a range of choices in between such as developing cleaner technology, car-sharing systems for necessities and emergencies, or better community planning to discourage daily driving.

34. Fallacies of insufficiency
NOT ENOUGH evidence is provided

35. Hasty Generalization
This is a conclusion based on insufficient or biased evidence. In other words, you are rushing to a conclusion before you have all the relevant facts.

37. Examples of Hasty Generalization
I met a Lebanese woman today who was incredibly smart and kind; therefore, all Lebanese women must be smart and kind.
The weather was really hot yesterday; therefore, that must be evidence of global warming.
The weather was really cold yesterday; therefore, global warming must not exist.

38. Circular reasoning or Begging the Question
This restates the argument rather than actually proving it.

40. Circular Reasoning Examples
Whatever is less dense than water will float, because such objects won't sink in water
If such actions were not illegal, then they would not be prohibited by the law.

41. Other common logical fallacies

42. Slippery Slope
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, 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.

44. Examples of the Slippery Slope Fallacy
We have to stop the tuition increase! The next thing you know, they'll be charging $40,000 a semester!"
"The US shouldn't get involved militarily in other countries. Once the government sends in a few troops, it will then send in thousands to die."
If we ban Hummers because they are bad for the environment eventually the government will ban all cars, so we should not ban Hummers.

45. Post Hoc (Ergo propter hoc)
This is a conclusion that assumes that if 'A' occurred after 'B' then 'B' must have caused 'A.'

47. Post Hoc Examples
The rooster crowed, and then the sun came up. Therefore, the rooster caused the sun to come up.
I took a pill and then felt better. Therefore, the pill cured my illness.

48. Syllogism
Syllogism is a rhetorical device that starts an argument with a reference to something general and from this it draws conclusions about something more specific. Syllogism is a three-part set of statements; a major statement or premise, a minor statement or premise and a conclusion that is deduced.
Example: All crows are black and the bird in my cage is black. So, the bird in my cage is a crow.
This is a false argument as it implies a conclusion “all black birds are crows,” which is incorrect.

49. Bandwagon (ad populum)
“Everybody’s doing it, so it must be a good thing to do” (Aufses et al. 111).
This is an emotional appeal that speaks to positive (such as patriotism, religion, democracy) or negative (such as terrorism or fascism) concepts rather than the real issue at hand.
Statistics can sometimes be manipulated to give a bandwagon appeal the appearance of logos.
Example:
If you were a true American you would support the rights of people to choose whatever vehicle they want.
In this example, the author equates being a "true American," a concept that people want to be associated with, particularly in a time of war, with allowing people to buy any vehicle they want even though there is no inherent connection between the two.

50. Appeal to false authority
“Someone who has no expertise to speak on an issue is cited as an authority” (Ausfes et al. 110).
This often happens with celebrities endorsing products.
Verify ethos to avoid this fallacy.

51. Key Fallacies to Review
Red Herring
Circular Reasoning
and Ad-hominem
Slippery Slope
Faulty Analogy
Post Hoc
Straw Man
Syllogism
Either/Or Fallacy
Bandwagon (Ad Populum)
Hasty Generalization
Appeal to False Authority