1. Presentation: Fallacies - Relevance vs. Weak Induction

2. Homework Study Fallacies 1-18 Review pp. 103-132
Fallacies (definition § 4.1)
§ 4.2 Fallacies of Relevance (1 – 8)
§ 4.3 Fallacies of Weak Induction (9 – 14)
For Next Class: pp
§ 4.4 Fallacies of Presumption & Ambiguity (15 – 22)

3. Fallacies of Relevance

4. Relevance vs. Weak Induction
Fallacies of Relevance
Premises are logically immaterial to conclusion
Typical features:
tactic of distraction
conclusion rests on emotional appeal
Premises may appear to be psychologically relevant
Fallacies of Weak Induction
Premises are relevant to conclusion
Insufficient evidence to warrant conclusion

5. Fallacies of Relevance
Appeal to Force
Appeal to Pity
Appeal to the People
Direct
Indirect
Argument against the Person (Ad hominem)
Abusive
Circumstantial
You, too!
Missing the Point
Of Accident
Straw Man
Red Herring
In each case,
The premises are immaterial to conclusion
Premises often distract attention from relevant evidence

6. Fallacies of Relevance
Appeal to the People
Two Kinds
Direct Approach
Appeal to group
Appeal to emotions, either positive or negative
Evidence overlooked due to cloud of emotional attachment
Indirect Approach
Appeal to individuals
Appeal to attachment or relationship to crowd
Evidence overlooked in favor of emotional attachment
Political speech
Advertisements

8. Fallacies of Relevance
Ad Hominem Arguments (against the person)
Three varieties
Abusive: attack on character of arguer
Turn attention away from the argument to the arguer
Circumstantial: attack by reference to specific irrelevant circumstances affecting arguer
Evidence for proposed conclusions overlooked in such attacks
You, too!: attack by charge of hypocrisy
Irrelevant behavior characteristics overshadow argument

10. Fallacies of Relevance
Red Herring (stinky fish)
Someone diverts attention from subject at hand
Introduction of a controversial, hot-button issue
The original argument tied illegitimately to controversial position (the stinky fish)
Controversial position attacked for its outlandishness

11. Fallacies of Relevance
Weak Induction
The premises are relevant to conclusion
Premises provide insufficient evidence to warrant conclusion
Relevance
The premises are immaterial to conclusion
Premises often distract attention from relevant evidence
Fallacies of Relevance
Example: Question of Evidence (red herring)? Appearing on ABC's This Week, the Ohio Republican (Minority Leader John Boehner) was asked what to describe the GOP plan to dealing with greenhouse gas emissions, "which every major scientific organization said is contributing to climate change." Boehner replied: "The idea that carbon dioxide is a carcinogen that is harmful to our environment is almost comical. Every time we exhale, we exhale carbon dioxide. Every cow in the world, you know when they do what they do you've got more carbon dioxide." "It's clear we've had change in our climate," he added. "The question is how much does man have to do with it and what is the proper way to deal with this? We can't do it alone as one nation."
Two Distinct Fallacies
Red Herring?
Oversimplification?
The Huffington Post, “Boehmer Cites Cow Farts to Downplay Global Warming”

12. Fallacies of Relevance
Straw Man
Someone misrepresents another’s argument
Presents weaker argument
Straw man vs. real man
Attacks weaker argument as if it were the original
Distorted argument often a fabrication

13. Fallacies of Relevance
The Darwinian theory of evolution cannot be true. Evolution asserts that the human being is a descendant of certain primate species. My parents are certainly human, as were theirs. Just as it is absurd to believe that a human being could birth a chimpanzee, it is absurd to believe a monkey could produce a human.
A misrepresentation of Dawinian theory of evolution.
As such irrelevant evidence against.

14. Fallacies of Relevance
Question of Evidence?
" The most talked-about aspect of the defense case undoubtedly concerned Mark Fuhrman, the LAPD officer who had found the bloody glove and who, as a prosecution witness, denied using the word "nigger." It turned out that Fuhrman had used "the n word"--many times--and it was on tape. Laura Hart McKinny, an aspiring screenwriter from North Carolina, had hired Fuhrman to consult with her on police issues for a script she was writing. McKinny taped her interviews with Fuhrman, who not only used the offensive racial slur, but disclosed that he had sometimes planted evidence to help secure convictions. Needless to say, the defense wanted McKinny on the stand, and they wanted the jury to hear selected portions of her tapes. The prosecution strenuously objected, arguing that McKinny's testimony was irrelevant absent some plausible evidence suggesting that evidence was planted in the Simpson case. The prejudicial value of the testimony, the prosecution insisted, would exceed its probative value.”
The Trial of O.J. Simpson by Doug Linder

15. Fallacies of Relevance
Appeal to Force
Appeal to Pity
Appeal to the People
Direct
Indirect
Argument against the Person
Abusive
Circumstantial
You, too!
Missing the Point
Of Accident
Straw Man
Red Herring
Premises are logically immaterial to conclusion
Attention drawn away from supporting evidence
appeal to some irrelevant concern
often intentionally deceptive
Premises appear relevant

16. Homework Study Fallacies 1-18 Review pp. 103-132
Fallacies (definition § 4.1)
§ 4.2 Fallacies of Relevance (1 – 8)
§ 4.3 Fallacies of Weak Induction (9 – 14)
For Next Class: pp
§ 4.4 Fallacies of Presumption & Ambiguity (15 – 22)