1. Persuasive Appeals AP LANGUAGE AND COMPOSITION Logos
Logos includes data, statistics, proven facts.
It also includes logical arguments… Arguments that make sense! Reasoning!

2. Logos = Logic
Reason (objective proof) is used to spell out claims that are logically sound and supported by reliable evidence.
Logic can be either deductive, inductive, or both

3. Premise vs. Conclusion
Ask yourself what you are trying to prove. What is your conclusion?
The statements that give your reasons are your premises.
I am an optimist. It does not seem to be much use being anything else. (Churchill)
“I am an optimist” is the conclusion
“It does not seem to be much use being anything else” is the premise or reason for the conclusion

4. Premises vs Conclusion
A dog was kept in the stalls, and yet, though someone had been in and fetched out a horse, [the dog] had not barked Obviously the visitor was someone whom the dog knew well. (Sherlock Holmes in “The Adventure of Silver Blaze”
Explicit Premise: the dog didn’t bark
General fact premise: he assumes we know that all dogs bark at strangers
Conclusion: The visitor wasn’t a stranger.

5. Distinguishing the Difference
What is the author trying to convince you to believe? This is the claim/conclusion
Conclusion indicators: therefore, thus, hence, so, consequently, this shows that
Then ask what reasons the author gives to convince you. These are the premises.
Premise indicators: because, since, given that, for, on the grounds that, this follows from

6. Inductive Reasoning Particular to the general
Generalizations are made on an observed fact (often used in scientific experimentation).
Easiest for the audience to accept because evidence is provided
Example: Every patient suffering from flu that the doctor examined had a fever. Therefore, fever must be a symptom of flu.

7. Deductive Reasoning - Syllogism
moving from the general belief to the particular
every syllogism contains at least three parts:
a major premise (global assumption)
a minor premise (specific claim)
a conclusion

8. An example of a syllogism
all men are mortal
(major premise)
Socrates is a man
(minor premise)
(conclusion)
Socrates is mortal

9. A visual representation
all things mortal
all men are mortal
men
Socrates is a man
Socrates
Socrates is mortal

10. An example of a syllogism
all mammals have hair
fish do not have hair
(major premise)
(minor premise)
(conclusion)
fish are not mammals

11. A visual representation
all things with hair
all mammals have hair
mammals
fish do not have hair
fish
fish are not mammals

12. A visual representation
bad drivers
All women are bad drivers.
woman
Jean is a woman.
Jean
Jean is a bad driver.

13. Simple Syllogism Practice

14. What is an enthymeme? sometimes called a “truncated syllogism”
a syllogism without stating either the major or minor premise (it is implied)
less formal than the syllogism
sometimes more persuasive

15. An example of an enthymeme
We cannot trust this man because he has perjured himself in the past.
Enthymemes are often
“because” statements.

16. The syllogism behind this enthymeme…
Those who perjure themselves
cannot be trusted.
This man perjured himself
in the past.
This man cannot be trusted.
(major premise)
(minor premise)
(conclusion)

17. Find it and challenge it.
Beware. Think Critically.
Enthymemes are sometimes used to hide the underlying assumption upon which an argument is based.
Find it and challenge it.

18. What are the unstated assumptions?
I failed that course because the instructor didn’t like me.
Assumption: The instructor fails students he doesn’t like.
I’m not surprised he made the team. After all, his father is the superintendent of schools.
Assumption: The superintendent gives special favors to his family
If I’d only taken my boss to lunch more often, I could have gotten that raise.
Assumption: The boss denies raises to people who don’t take him to lunch very often.

19. Practice

20. We shouldn't elect Joe as committee chair because he is too bossy Claim: We shouldn't elect Joe as committee chair Data: because he is too bossy Warrant:

21. BOSSY PEOPLE MAKE BAD COMMITTEE CHAIRS.
Warrant

22. Buy this stereo system because it has a powerful amplifier Claim: Buy this stereo system Data: because it has a powerful amplifier Warrant:

23. STEREO SYSTEMS WITH POWERFUL AMPLIFIERS ARE WORTH BUYING.
Warant

24. Drugs should not be legalized because legalization would greatly increase the number of drug addicts. Claim: Drugs should not be legalized Data: because legalization would greatly increase the number of drug addicts. Warrant:

25. INCREASED ACCESS TO DRUGS WILL LEAD TO MORE ADDICTS.
Warrant

26. Practicing the piano is good for kids because it teaches discipline Claim: Practicing the piano is good for kids Data: because it teaches discipline Warrant:

27. KIDS NEED TO BE TAUGHT DISCIPLINE.
Warrant

28. Welfare benefits for unwed mothers should be eliminated because doing so will greatly reduce the nation's illegitimacy rate. Claim: Welfare benefits for unwed mothers should be eliminated Data: because doing so will greatly reduce the nation's illegitimacy rate. Warrant:

29. WELFARE BENEFITS ENCOURAGE ILLEGITIMACY.
Warrant

30. Welfare benefits for unwed mothers should not be eliminated because these benefits are needed to prevent unbearable poverty among our nation's most helpless citizens. Claim: Welfare benefits for unwed mothers should not be eliminated Data: because these benefits are needed to prevent unbearable poverty among our nation's most helpless citizens. Warrant:

31. UNWED MOTHERS ARE HELPLESS AND POVERTY-STRICKEN WITHOUT WELFARE BENEFITS.
Warrant

32. We should strengthen the Endangered Species Act because doing so will preserve genetic diversity on the planet.
Claim: We should strengthen the Endangered Species Act
Data: because doing so will preserve genetic diversity on the planet.
Warrant:

33. THE ENGDANGERED SPECIES ACT PRESERVES GENETIC DIVERSITY.
Warrant

34. The Endangered Species Act is too stringent because it severely damages the economy.
Claim: The Endangered Species Act is too stringent
Data: because it severely damages the economy.
Warrant:

35. OVERLY STRINGENT ACTS DAMAGE THE ECONOMY.
Warrant