1. The Logical Structure of Arguments (WA Chapter 4)
CS4001
Kristin Marsicano

2. Formal vs. Real-World logic
What is the difference?
What is the role of assumptions?

3. Formal vs. Real-World logic
What is the difference?
Formal logic
“if all ps are qs, and if r is a p, then r is a q”
represents something provable
Real-world logic
Not so cut and dry; we want to know the particulars on a case-by-case basis
Difficult to say rs are always ps, or that every instance of p results in q
What is the role of assumptions?
Real-world arguments are not grounded in abstract, universal statements; instead must be grounded in believes, assumptions, or values granted by the audience
beliefs, assumptions, or values are often unstated! Note, if the underlying assumptions aren’t shared, the writer has a problem (they must defend the assumption)

4. Formal vs. Real-World Logic
In your term paper, which will you be dealing with?

5. Formal vs. Real-World Logic
In your term paper, which will you be dealing with?
Real-world logic, which is why we avoid using the word “prove”
your paper is not meant to prove anything
instead, it’s meant to make a good case – to weaken the resolve of those who resist your claim or strengthen the resolve of those who agree

6. Who is Stephen Toulmin?

7. Who is Toulmin? Stephen Toulmin British philosopher
1950s - Rejected model of argument based on formal logic
Developed an alternate model
to analyzing/developing
arguments

8. Toulmin Model: Assumptions
Audience-based courtroom model
Assumes:
All assertions and assumptions are contestable by an “opposing council” (as in court)
Verdicts will be rendered by a neutral (3rd) party (the judge, the jury, or (in your case) the reader)
Framing the argument with the courtroom in mind helps you think about reasons for both supporting and opposing your case

9. Toulmin Model: Key Terms
Claim
Reason
Enthymeme
Grounds
Warrant
Backing
Rebuttal

10. Recall: Definition of Argument

11. Recall: Definition of Argument
A claim supported by a reason, usually stated as a because clause

12. Enthymeme
What is it?
Give an example; outline the unstated underlying assumption

13. Enthymeme What is it? Give an example (from WA ch. 4:)
incomplete logical structure
claim and reason that depends on on unstated assumptions
To serve as a starting point for the argument, underlying assumptions should be a belief, value, or principle shared by the audience
Give an example (from WA ch. 4:)
“The public school should not support marine parks and “swim with dolphins” programs because these programs separate dolphins from their natural and social groups”
Assumption: Wild animals should remain free in their natural habitats and social groups

14. Enthymeme Exercise
Given each of the following enthymemes, identify the unstated assumption the audience must supply in order to make the enthymeme persuasive.
Dogs make good pets because they are loyal.
We shouldn’t elect Joe as a committee chair because he is too bossy.
Drugs should not be legalized because legalization would greatly increase the number of drug addicts.
We need laws to control the sale of guns because so many innocent people are getting killed.

15. Warrant

16. Warrant
Underlying assumption that turns an enthymeme into a complete, logical structure
Value, belief, or principle that audience has to hold if the soundness of the the argument is to be guaranteed

17. Grounds

18. Grounds “What grounds do you have to support your claim?”
E.g. “the grounds for divorce”
Should answer “how do you know that…”
Evidence supporting the claim’s reason
Facts, data, statistics, causal links, testimony, examples, anecdotes, etc.

19. Backing

20. Backing Argument that supports the warrant
Must be introduced when the warrant itself is not convincing enough to the audience

21. Backing
Example:
“Affirmative Action is a necessary initiative to help minorities achieve equality in education and employment.”
What is the warrant (underlying assumption)?

22. Backing
Example:
“Affirmative Action is a necessary initiative to help minorities achieve equality in education and employment.”
What is the warrant (underlying assumption)?
- Equality should be achieved, but is has not been already
What if your reader believe that minorities have already achieved equality in education and employment? How could you convince them otherwise?

23. Rebuttal
What are the two main front on which someone could rebut your argument?

24. Rebuttal
What are the two main front on which someone could rebut your argument?
Reasons or grounds
Warrants or backings
To strengthen your argument, acknowledge and address:
that there are limitations on your claim
that you are aware of the opposing point of view

25. Qualifier

26. Qualifier
Expresses author’s degree of certainty concerning the claim (limit force of claim, indicate degree of probable truth)
Very likely, probably, maybe, except for, etc..

27. Putting it all together: Applying Toulmin
We can apply the Toulmin Schema to analyze another person’s argument, or to build our own!
I recommend you try this exercise when constructing the argument for your term paper.

28. The Importance of Audience-Based Reasons
“Whenever you ask whether a given piece of writing is persuasive, the immediate rejoinder should always be, ‘Persuasive to whom?’”
Consider our friend Gordon Adams (remember him?)

29. Applying Toulmin to Gordon’s Argument
Enthemyme:
Claim:
Reason:
Grounds:
Warrant:
Backing:
Who was Gordon’s audience? How did the warrant relate to that audience? How might he have have created a more persuasive argument?

30. Putting it all together: Applying Toulmin
Example provided from book:
Dolphins
Bossy Joe
Drugs