Showing posts with label explain. Show all posts
Showing posts with label explain. Show all posts

Tuesday, April 26, 2016

Informal Fallacies: Fallacy Fest!



FALLACY FEST!!!!



1. Bad/DA

2. Bad/AC

3. Appeal to Authority

4. Fallacy of Equivocation

5. Hasty Generalization

6. Ad Baculum (Appeal to Force)

7. Red Herring

8. Appeal to Authority

9. Ad Hominem

10. Ad Misercordiam (Appeal to Pity)

11. Begging the Question

12. Straw Man

13. Complex Question

14. Internet Fallacy



Identify the (Bad) Reasoning Fallacy then Create 1 Example of Your Own

Concept 1:

A: Person 1: Everything in life happens for a reason...maaaaaaaaaaaaaaaan. There's a greater purpose to everything.

Person 2: That's ridiculous. What's the reason for my moving my finger right now?

Person 1: Because you had the thought "move your finger" which caused the nerves leading to your finger to fire in succession, culminating in the movement of your finger...duh.


B: Science has discovered many laws of nature. This surely constitutes proof that there is a God, for wherever there are laws, there must be a lawgiver. Consequentially, God must exist as the great lawgiver of the universe.


C: Since, as scientists tell us, energy neither comes into being nor goes out of being, there should be no energy crisis.









Fallacy of Equivocation: The fallacy of equivocation is when a key term in the argument isn't used with a consistent meaning throughout the premises and/or conclusion. In other words, a term might be used differently between premises or between the premises and the conclusion.

Concept 2:


A: Why should I believe what he says about our economy? He's not even a citizen!


B: You can't accept her advice. She is so old she has no idea what goes on in today's world.


C: Why would you listen to him? He's too young to have any wisdom about life.


D*: Of course Senator X thinks my administration's tax proposals are bad for the country. After all, his political party lost the last election, and everyone knows that losers are jealous.


E*: You don't want cars to get better gas milage because you are a self-centered rich bastard who isn't affected by gas prices. All you care about it how big your engine is.


F*: Of course you think that people should take drugs. You work for a pharmaceutical company and you make more money if more people take drugs.













Explanation of Ad hominem (against the person)
: When a claim is rejected or judged to be false based on an alleged character flaw of the person making the claim. A second form occurs whenever someone's statement or reasoning is attacked by way of a stereotype, such as a racial, sexual, or religious stereotype. A third form involves the use of circumstances of a person's life to reject his claims. Exception: denying someone's claim by calling them a liar and they have a reputation for being one.


Concept 3

A. Vaccines cause autism. Didn't you hear the interviews with Robert DeNiro and Jenny McCarthy?


B. The Food Babe says GMOs cause cancer. There's no way I'm eating those franken foods!













Explanation of Argument from Authority: Appealing to an unqualified authority to support a position.

Concept 4:

A.













Non-sequitur: Literally "does not follow". When a premise is irrelevant to the conclusion.



Concept 5:

A. Conrad Hilton started out dirt poor and became super-rich, therefore anyone can do it.

B. About half of my friends at BGSU have student loans, therefore about half of BGSU students have student loans.

C. Acupuncture helped my back feel better, it must work.












Hasty Generalization: Moving from a small (likely unrepresentative sample) to a generalization.

Concept 6:

A.



B. Last night my mom got mad at me, then my dog got sick. Can you change my grade from a C to a B?
















Appeal to Pity (Ad Misercordiam): Arguing for a claim by appealing to pity.

Concept 7:

A: If you don't get rid of your suspected chemical weapons we will bomb you.

B: If you don't do your homework, I will judo chop you.














Appeal to Force (Ad Baculum): When the arguer essentially presents a threat of force instead of a reason for accepting a position.

Concept 8:

A. Person A: Given the tragic nature of mass shootings, we should consider implementing some sort of background check to make sure people buying guys don't have any known major psychological problems or any records of violent criminal behavior.

Person B: My opponent doesn't think people have the right to own guns. In person A's world, citizen's won't be able to lawfully defend themselves or even go hunting.







B. Person A: If you deny people the right to self-defense then you are risking increasing the rate home break-ins because a major deterrent will have been removed.

Person B: My opponent thinks we should give children AK-47s for self-protection when their parents aren't home. This is obviously a bad idea.













Straw Man: The opposing view is distorted and exaggerated so it can easily be defeated.

Concept 9:

A. (From the Washington Post)
BLM contends that Bundy owes $1 million in fees, and will also have to pay the round-up expenses. Bundy — who retorts that he only owes $300,000 in fees — says the city folk are only hurting themselves by taking his cows. He told a reporter from the Las Vegas Review Journal that there would be 500,000 fewer hamburgers per year after his cows were towed away; “But nobody is thinking about that. Why would they? They’re all thinking about the desert tortoise. Hey, the tortoise is a fine creature. I like him. I have no problem with him. But taking another man’s cattle? It just doesn’t seem right.”




B. How could anyone think GMOs are safe? They're inserting fish genes into tomatoes!!!!!111!!!1111!!! It just ain't natural!!!!11!!!!11!!













Red Herring Structure:

Topic A is under discussion.
Topic B is introduced as though it is relevant to topic A.
Topic B ends up being discussed, leaving topic A unresolved.





















Concept 10:

A. Celibacy is an unnatural and unhealthy practice, since it is neither natural nor healthy to exclude sexual activity from one's life.

B. Thoughts are not part of the physical world, since thoughts are in their nature non-physical.

C. Happiness is the highest good for a human being, since all other values are inferior to it.
















Begging the Question: When you assume your conclusion, implicitly or explicitly, in your premises. That is, your premises already assume they very thing you're trying to prove.

Concept 11:


A. Are you going to admit that you're wrong?

B. When should I expect your apology?

C. Why do you hate America?

D. When are you going to stop drinking and grading?














Complex Question: When a question assumes only one possible answer.

Tuesday, April 12, 2016

More Reductio, Translations with 'v', Logical Equivalence

Agenda
  1. Quiz
  2. Questions about homework?
  3. Law of non-contradiction and law of the excluded middle. 
  4. Translating sentences with 'v'.
  5. Logical Equivalence.
  6. RA proofs.
Quiz
A. 

  1. /:. (P&Q)>~(P>~Q)
B. 
1. Either you'll get this RIGHT or you won't unless CONTRADICTIONS are true.
2. You can have a sticker only if you either make no MISTAKES or bring me a COOKIE. 



Law of Non-Contradiction
Definition: The negation of a contradiction is always true.
Symbolized: ~(P&~P) = True

E.g., 
  1. The fact that I'm both alive and not alive is false. This whole sentence is true.
  2. The fact that the room is both empty and not empty is false. This whole sentence is true.
  3. The fact that I like cookies and don't like cookies is false. This whole sentence is true.
The Law of the Excluded Middle
Definition: The assumption that any sentence is either true or false is always true.
Symbolized: Pv~P = True

E.g.,
  1. Either I'm going to study or I'm not going to study. The whole sentence is true.
  2. Either you are wearing pants or you are not wearing pants. This whole sentence is true.
  3. Either Bob is here or he isn't here. This whole sentence is true. 
Translations with 'v'
A.

  1. Either I'm not going to STUDY or I'm not going to WATCH  a movie. 
  2. Unless you WORK hard you'll either make your MOTHER cry or your FATHER angry. 
  3. You can have either COOKIES or DONUTS but you can't have both. (Careful!)
  4. You can have either COOKIES or DONUTS or both.
  5. You can have neither COOKIES nor DONUTS unless you HELP me. 
  6. I would HIKE Death Valley only if either my BROTHER or JEREMY came with me.
  7. You can have neither COOKIES nor DONUTS unless you EAT your dinner.
Logical Equivalence 
A. 
  1. /:. (P>Q)<>(~Q>~P)
Reductio Proofs (left over from last week)

D. 
  1. ~D>(A&C)
  2. (B&D)>E
  3. (DvF)>~E  /:. ~(A&C)>~(Bv~D)
E. 
  1. (R&S)>~(P>~Q)
  2. ~(T>P)>(R&S)
  3. T
  4. ((T>P)&P)>Q        /:. ~(P>Q)
F.
  1. (~D&~E)>F
  2. A&~D
  3. ((F&~B)vG)>~(A>~B)    /:.  (A>~B)>~(Dv~E)








Friday, February 19, 2016

Conditional Proofs 2

Agenda

  1. Quiz
  2. Please help me! help you! during office hours if you couldn't do the quiz question.
  3. Reset/Taking stock
  4. Questions from HW?
  5. Affirming the consequent/Denying the antecedent
  6. Practice proofs
Quiz
1. A>B
2. ~A>~C
3. D&E /:.  ~B>(~C&D)



















How to set up a conditional proof:
If you have to solve for a conditional,
1. write the conditional at the bottom of your proof;
2. write the antecedent of the conditional you're trying to prove on the line immediately below the last given premise/assumption OR if there are no premises/assumptions, write it at the top of the proof. Write 'ACP' in the justification column.
3. write the consequent on the line above the conditional you're trying to prove.

Example: 
I'm asked to solve for (P&Q)>Q
Step one: write the conditional at the bottom of your proof
.
.
.
.
.
.
.
(P&Q)>Q           CP _____

Step two: write the antecedent of the conditional you're trying to prove on the line immediately below the last given premise/assumption OR if there are no premises/assumptions, write it at the top of the proof. Write 'ACP' in the justification column.

P&Q                  ACP
.
.
.
.
.
.
(P&Q)>Q          CP

Step three: write the consequent on the line above the conditional you're trying to prove.

P&Q                 ACP
.
.
.
.
.
Q                    ______
(P&Q)>Q       CP

Now that the CP proof has been set up, you solve it the way you'd solve any proof. All you're trying to do is justify Q.


Proofs with CP rule
A.
  1. ~C>~A /:. (A&~B)>(~B>C)
B.
  1. P>Q
  2. ~P>~R /:. ~Q>~R
C. 
  1. P
  2. ~R    /:.  (P>(~Q>R))>(~S>(T>(Q&~S))
D.

      /:.  P>(~Q>(R>(~S>(R&~S))))

E.  
  1. (R&T)>~Q
  2. ~S>R
  3. P    /:. (P>(T&~S))>(U>(~Q&T))

Friday, February 5, 2016

Modus Tollens and Conjunction Rules

Class
1. Review:

  • Validity
  • Translation
  • Modus tollens (MT)
2. Conjunction Rules (&In and &Out)
3. Bonus Office Hours This Week: 4:20pm 3rd Floor Shatzel Hall, Seminar Room

Conjunction Rules: &In and &Out

A.  &In

  1. P
  2. Q
  3. P&Q

B.  &Out

  1. P&Q
  2. P/Q


Proofs with DN and MP Only
A.
  1. ~~(P>~~~Q)>~~~~S
  2. S>~~(Q>P)
  3. P>~~~Q
  4. (Q>P)>~~~T
  5. ~T>Q  /:. ~~Q



Proofs 
MT Only
B. 
  1. ~A>(B>C)
  2. ~(B>C)
  3. A>~B  /:. ~B
C. 
  1. ~S>(Q>~R)
  2. P
  3. (Q>~R)>~P  /:. S
MP, MT, DN
D. 
  1. ~(P>Q)>(R>~S)
  2. R
  3. (P>Q)>~R  /:. ~S
E. 


  1. T>U
  2. ~(~P>~Q)>(~R>~S)
  3. (~R>~S)>~(T>U)
  4. ~P   /:.  ~Q
F. 
  1. ~Q>T
  2. P
  3. ~(P>~Q)>(~R>T)
  4. ~(~R>T)
  5. S>~T  /:. ~S
MP, MT, DN, &In, &Out
H. 
  1. ~E>~A
  2. A>B
  3. (A>B)>(A>~(D&E)
  4. A>D
  5. A










Monday, February 1, 2016

Modus Ponens, Negation, and Double Negation




Today's Class Content
1. Review:
  • Validity
  • Translation of conditionals
2. Homework Questions/Problems? 
3. New content:
    (a) Translating with negations.
    (b) Double Negation rule (DN). 
    (c) Modus Tollens.
4. Basic proofs with negation.



Negatins and Double Negation (DN)
Translations
1.  If you Study you won't Fail.
2. Mark will be disappointed if you don't know who Rain man is.
3. I wouldn't leave my Nuts uncovered for winter if I were a Squirrel.
4. If you don't use your Cellphone in class I won't have to Judo chop you.


Proofs
MP rule says if I have the antecedent of a conditional I can write down the consequent. However, in order to apply MP I have to have the exact antecedent. Even if I have an antecedent that is logically equivalent, I can't apply the rule.

Example:
1. P>Q
2. ~~P /:. Q

WRONG:
1. P>Q       A
2. ~~P        A
3. Q           MP 1, 2

In order to use MP I need P because P not ~~P is the antecedent. ~~P will not work. However, I can change ~~P into P by applying double negation rule (DN).

CORRECT:
1. P>Q      A
2. ~~P       A
3. P           DN 2
4. Q          MP 1,3

DN and Parenthesis

Modus Tollens
Modus tollens is like a modus ponens in reverse. It has the following structure: one premise is a condidtional and the other premise is the negation of the consequent. The conclusion is the negation of the antecedent. 

Here's an example:
P1. If [I put Money in the machine] then [I'll get a Snickers bar].
P2. [I don't have a Snickers bar].
C.  [I didn't put Money in the machine].

Symbolized, modus tollens looks like this:
1. M>S
2. ~S ('~' means 'not')
3. ~M

Exercises
MP + DN Only
A.
  1. (A>B)>(C>D)
  2. A>B
  3. ~~C  /:. D
B. 
  1. S>(T>P)
  2. P>(Q>~R)
  3. ~~P
  4. ~R>S
  5. Q     /:. ~~(T>P)
C. 
  1. ~((~A>B)>(C>~D))
  2. ~~~((~A>B)>(C>~D))>(B>C)
  3. ~~~E>F
  4. ~~(B>C)>~E   /:.  F
D.
  1. ~~(P>~~~Q)>~~~~S
  2. S>(~~Q>P)
  3. P>~~~Q
  4. (Q>P)>~~~T
  5. ~T>Q  /:. ~~Q
MT Only
E. 
  1. ~A>(B>C)
  2. ~(B>C)
  3. A>~B  /:. ~B
F. 
  1. ~S>(Q>~R)
  2. P
  3. (Q>~R)>~P  /:. S
MP, MT, DN
G. 
  1. ~(P>Q)>(R>~S)
  2. R
  3. (P>Q)>~R  /:. ~S
H. 
  1. T>U
  2. ~(~P>~Q)>(~R>~S)
  3. (~R>~S)>~(T>U)
  4. ~P   /:.  ~Q