1. FIVE TYPES OF REASONING

2. Inferring general conclusions from specific cases.
Reasoning by EXAMPLE
Inferring general conclusions from specific cases.
Claim: Wal-Mart stores benefit the community.
Little Rock, Arkansas – 20% economic boost in the first year
Stamford, Mass. – 15 % economic boost in the first year

3. therefore it is always true.”
Reasoning by EXAMPLE
Inferring general conclusions from specific cases.
“My claim was true in
A, B, C, and D,
therefore it is always true.”

4. CHALLENGES to use against this type of reasoning:
Reasoning by EXAMPLE
CHALLENGES to use against this type of reasoning:
Are the examples relevant?
Are there enough examples?
Are the examples typical or representative?
Do the examples cover a critical period of time?
Can negative examples be explained?

5. Reasoning by SIGN
Inferring that the presence of signs indicate the presence of another factor.
Claim: South is an excellent school.
High # of National Merit Winners
High % of grads go to college
Excellent faculty
Wide range of activities for students

6. “A, B, C, and D are signs that overall we are seeing X.”
Reasoning by SIGN
Inferring that the presence of certain signs indicate the presence of another factor.
“A, B, C, and D are signs that overall we are seeing X.”

7. CHALLENGES to use against this type of reasoning:
Reasoning by SIGN
CHALLENGES to use against this type of reasoning:
Is the relationship between factors just incidental?
Do counter-signs exist?
Are there enough signs to draw a conclusion?

8. Reasoning by ANALOGY
Inferring that because a claim is true in one situation, it will be true in this other similar situation.
Claim: “Open campus” would work at South because it works at Clayton HS.
Clayton HS has an open campus and it is rarely abused.

9. Reasoning by ANALOGY
Inferring that because a claim is true in one situation, it will be true in this other similar situation.
“Situation A is enough like situation B, that we are able to say that what happened in A will also happen in B.”

10. CHALLENGES to use against this type of reasoning:
Reasoning by ANALOGY
CHALLENGES to use against this type of reasoning:
Are there significant points of similarity?
Are the points of similarity critical to the comparison?
Are there any relevant differences?
Is the analogy literal and not figurative?

11. Reasoning by AUTHORITY
Inferring a claim is true because an expert says it is true.
Claim: The Surgeon General warns that cigarette smoking is hazardous to your health.
Claim: Parkway South is a good school because Mr. H says it is.

12. Reasoning by AUTHORITY
Inferring a claim is true because an expert says it is true.
This source says “A.”
Therefore A must be true.

13. Reasoning by AUTHORITY
CHALLENGES to use against this type of reasoning:
Is the authority qualified on the issue?
Is the authority trustworthy?
Is the authority unbiased?

14. Inferring that a certain factor directly resulted in another factor.
CAUSAL reasoning
Inferring that a certain factor directly resulted in another factor.
Claim: Carrying heavy backpacks causes spinal damage.
Claim: Listening to explicit lyrics in music results in higher rates of violence among teens.

15. Inferring that a certain factor directly resulted in another factor.
CAUSAL reasoning
Inferring that a certain factor directly resulted in another factor.
A = B

16. CHALLENGES to use against this type of reasoning:
CAUSAL reasoning
CHALLENGES to use against this type of reasoning:
Is the cause-effect link relevant?
Do other causes also produce the effect?
Can the effect exist without the cause?
Is the link a correlation rather than a cause?

17. “AUTHORITY=PLUS”
In debate, we are ALWAYS giving SOURCES for all of our evidence.
So, we are ALWAYS using reasoning by authority in combination with other forms of reasoning.
External refutation--attacks the source.
Internal refutation--attacks the source’s reasoning.