Logic

1
Logic Reasoning

• Explanation
• Argument
• Premise
• Inference
• Final Conclusion

2
Bob is barfy. On account that the nurse can give
Bob something to help him feel better, therefore,
Bob should go to the nurse.
3
Since Fred can type 200 words a minute, he types
fast.
4

• Smallpox is no longer a threat to anyone in the
  US. And the vaccination against it is unpleasant
  and, in rare cases, life-threatening. We were
  wise when we ceased the routine vaccination of
  our children.

5

• Bamboo can grow up to four feet a day, but only
  after it is well established. This can take from
  three to five years, depending on the type of
  bamboo.

6

• The Taipei study of the spread of SARS doesnt
  establish its conclusion at all. The sample for
  the study was too small and wholly
  unrepresentative of the total population.

7

• Younger children benefit more from flu shots
  than older people, so the government should worry
  more about making sure kids get flu shots.

8

• GPAs at NKU should be higher this year. Since
  NKU increased admissions standards last year,
  students are better this year. 

9
Arguments

• Simple Argument
• Premise
• (Inference)
• Final Conclusion
• ---OR---
• (More than one) Premise(s)
• (Only ONE Inference)
• Final Conclusion

10
Arguments

• Complex Argument
• Premise
• (Inference)
• Intermediate Conclusion (Premise)
• (Inference)
• Final Conclusion
• --OR--
• (Multiple) Premise(s)
• (Multiple) Intermediate Conclusion(s) (Premises)
• Final Conclusion
• (Any number of Ps and ICs in any combination, but
  leading to only one FC)

11
Arguments

• Complex Argument Example
• Premise
• Premise
• (Inference)
• Intermediate Conclusion (Premise)
• Premise
• Premise
• (Inference)
• Intermediate Conclusion (Premise)
• Final Conclusion

12

• Pink elephants can fly because twelve people on
  safari witnessed this.

13

• It looks like a duck. It sounds like a duck.
  It even walks like a duck. It must be a duck.

14

• If an automobile is no longer being made, it
  earns antique status after 10 years. Since
  Chrysler no longer makes LeBaron convertibles,
  you can get antique plates for your 15-year-old
  LeBaron.

15

• Joe could save a lot of money. Since he only
  drinks freshly-brewed fru-fru coffee, he goes to
  Starbucks rather than saving money with the
  vending machine coffee.

16
Evaluating Arguments

• Deductive Arguments
• Sound Arguments
• Nondeductive Arguments
• Successful
• Nonsuccessful

17

• The last person to see the victim alive must
  have been the murderer, and Wainsworth was the
  last person to see the victim alive. Thus,
  Wainsworth must have committed the murder.

18

• All Democrats are liberals. All liberals want
  more government spending. Thus, all Democrats
  want more government spending.

19

• Most people who read The New Republic are
  liberals. Freedman reads The New Republic.
  Freedman is a liberal.

20

• In the phone survey, 58 of the registered
  voters intending to vote in the election said thy
  planned to vote for Larson. Larson will receive
  about 58 of the votes in the election.

21

• We have probable cause to believe that Joe
  committed the crime. His fingerprints were on
  the weapon, his DNA was found on the victim, and
  two independent witnesses testified that they saw
  him stab the victim.

22

• 500 of the 2,000 Cactus County Public Library
  cardholders were randomly selected and asked
  whether they prefer fiction or nonfiction. 338
  said they prefer fiction. Thus, you can be that
  most of Cactus County cardholders prefer fiction.

23

• Since Sandy has a proven IQ of 153 and is an
  experienced test-taker, she will do very well on
  the law school admissions exams next week.

24

• I asked several other students in my Advanced
  Algebra class what they thought of Professor
  Stewarts Intro to English Literature class last
  semester. Most of them were really bored with
  the lit class. So, Professor Stewart must be a
  really boring teacher. Im not sure I want to
  take his class.

25

• No former First Lady who subsequently became a
  US Senator has ever gone on to be President of
  the US. So none will ever be President.