Reasoning Critically about Argument and EvidenceSolid versus Sloppy Thinking

Reasoning Critically about Argument and Evidence.• Logical Reasoning. • An "enthymeme" • The Toulmin Method of Argument. • Looking Critically at the Evidence.

• Be aware of Logical Fallacies.• The Rogerian Method of Argument

Logical Reasoning• Sometimes the logic is not entirely

laid out:• There may be an "enthymeme"

– The informal method of reasoning typical of rhetorical discourse. The enthymeme is sometimes defined as a "truncated syllogism" since either the major or minor premise found in that more formal method of reasoning is left implied. The enthymeme typically occurs as a conclusion coupled with a reason.

An Example:• “We cannot trust this man, for he has

perjured himself in the past.”In this enthymeme, the major premise of the complete syllogism is missing: – Those who perjure themselves cannot be

trusted. (Major premise - omitted) – This man has perjured himself in the past.

(Minor premise - stated) – This man is not to be trusted. (Conclusion -

stated)

Other Ways of Thinking

Toulmin's Rhetorical Logic andRogerian argument

The Toulmin Method of ArgumentMade of Three Parts:• A claim:

– a conclusion based upon evidence; like the thesis of your research paper, it is an assertion you make and then defend.

• The evidence:– Supports the claim by including facts,

statistics, expert opinions, and other information that supports or leads to a conclusion.

The Toulmin Method Continued• The warrant:

– This is the rational behind the argument; it is an assumption or belief that you and your audience share

The Need to Qualify Arguments• Since it is rare that we can state any

opinion with absolute certainty--and rarer still that we can think of every possible exception to an argument--Toulmin logic calls for adding a qualifier– examples:

• some,• probably,• most

The Toulmin Method reminds us of the existence of the stated and unstated elements of argument.• Often the warrant of the argument can be

assumed but sometimes it is helpful to remind the reader of a basic common assumption:– The Historic position of the Nazarene Church

on Women’s Ministry.– What is meant by “believing in Evolution?”– The Historic position of the nature of

scripture.• Check the Manual; don’t just ask your pastor.

Toulmin' s Analysis

• Stephen Toulmin, a modern rhetorician, believed that few arguments actually follow classical models of logic like the syllogism, so he developed a model for analyzing the kind of argument you read and hear every day--in newspapers and on television, at work, in classrooms, and in conversation.

• Toulmin' s model focuses on identifying the basic parts of an argument. As a researcher and writer, you can use Toulmin' s model two ways:–  to identify and analyze your sources by identifying the

basic elements of the arguments being made, and– to test and critique your own argument.

Notice that commercials which might try this don't usually bother trying to convince you that you want whiter teeth; instead, they assume that you have bought into the value our culture places on whiter teeth. When an assumption--a warrant in Toulmin' s terms--is unstated, it's called an implicit warrant. Sometimes, however, the warrant may need to be stated because it is a powerful part of the argument. When the warrant is stated, it's called an explicit warrant. Toulmin says that the weakest part of any argument is its weakest warrant. Remember that the warrant is the link between the data and the claim. If the warrant isn't valid, the argument collapses.

Looking Critically at the Evidence• In a Inductive Argument

– the evidence leads logically to the conclusion.

• In a Deductive Argument– the evidence is stated in the premise

• In a “Toulmin argument:– the evidence supports the “claim” or

“thesis.”• Use Example and Authority

Examples:• Provide details

– facts,– Statistics– authoritative opinion

• Should be numerous enough to demonstrate the extend and variety of cases that support the conclusion

• Should be “typical” (not flukes)• Should be more than one.

Rogerian Argument • Carl Ransom Rogers (1902 – 1987)

was an influential American psychologist and among the founders of the humanistic approach (or client-centered approach) to psychology.

• Rogerian argument is a conflict solving technique based on finding common ground instead of polarizing debate.

Young, Becker and Pike identified four stages of How it Works• An introduction to the problem and a demonstration

that the opponent's position is understood.• A statement of the contexts in which the

opponent's position may be valid.• A statement of the writer's position, including the

contexts in which it is valid.• A statement of how the opponent's position would

benefit if he were to adopt elements of the writer's position. If the writer can show that the positions complement each other, that each supplies what the other lacks, so much the better.

Sites Cited• “Research and Citation—Toulmin.” The

Toulmin Project Home Page. University of Nebraska Lincoln. http://owlet.letu.edu/contenthtml/research/toulmin.html 22 April 2010.

• “Carl Rogers.” Wikipedia 6 May 2015• “Rogerian Argument” Wikipedia 6 May 2015

http://en.wikipedia.org/wiki/Rogerian_argument