Toulmin Logic

Source: Wikipedia

The Toulmin Model of Argument

Discovering absolutism’s lack of practical value, Toulmin aimed to develop a different type of argument, called practical arguments (also known as substantial arguments). In contrast to absolutists’ theoretical arguments, Toulmin’s practical argument focuses on the justificatory function of argumentation, as opposed to the inferential function of theoretical arguments. Whereas theoretical arguments make inferences based on a set of principles to arrive at a claim, practical arguments first find a claim of interest, and then provide justification for it. Toulmin believes that reasoning is less an activity of inference involving the discovering of new ideas, but more so a process of testing and sifting already existing ideas—an act achievable through the process of justification.

Toulmin believes that a good argument can succeed in providing good justification to a claim, which will stand up to criticism and earn a favourable verdict. In The Uses of Argument (1958), Toulmin proposed a layout containing six interrelated components for analyzing arguments:

Claim

Conclusions whose merit must be established. For example, if a person tries to convince a listener that he is a British citizen, the claim would be “I am a British citizen.” (1)

Data

The facts we appeal to as a foundation for the claim. For example, the person introduced in 1 can support his claim with the supporting data “I was born in Bermuda.” (2)

Warrant

the statement authorizing our movement from the data to the claim. In order to move from the data established in 2, “I was born in Bermuda,” to the claim in 1, “I am a British citizen,” the person must supply a warrant to bridge the gap between 1 & 2 with the statement “A man born in Bermuda will legally be a British Citizen.” (3)

Backing

Credentials designed to certify the statement expressed in the warrant; backing must be introduced when the warrant itself is not convincing enough to the readers or the listeners. For example, if the listener does not deem the warrant in 3 as credible, the speaker will supply the legal provisions as backing statement to show that it is true that “A man born in Bermuda will legally be a British Citizen.”

Rebuttal

Statements recognizing the restrictions to which the claim may legitimately be applied. The rebuttal is exemplified as follows, “A man born in Bermuda will legally be a British citizen, unless he has betrayed Britain and has become a spy of another country.”

Qualifier

Words or phrases expressing the speaker’s degree of force or certainty concerning the claim. Such words or phrases include “possible,” “probably,” “impossible,” “certainly,” “presumably,” “as far as the evidence goes,” or “necessarily.” The claim “I am definitely a British citizen” has a greater degree of force than the claim “I am a British citizen, presumably.”

The first three elements “claim,” “data,” and “warrant” are considered as the essential components of practical arguments, while the second triad “qualifier,” “backing,” and “rebuttal” may not be needed in some arguments. When first proposed, this layout of argumentation is based on legal arguments and intended to be used to analyze the rationality of arguments typically found in the courtroom; in fact, Toulmin did not realize that this layout would be applicable to the field of rhetoric and communication until his works were introduced to rhetoricians by Wayne Brockriede and Douglas Ehninger. Only after he published Introduction to Reasoning (1979) were the rhetorical applications of this layout mentioned in his works.

SOURCE: http://owlet.letu.edu/contenthtml/research/toulmin.html

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.

Please note that this page presents only a very simplified version of Toulmin's theory. For a more complete understanding, you should read Toulmin's book The Uses of Argument (Cambridge University Press, 1958).

Toulmin identifies the three essential parts of any argument as the claim, the data or evidence which is offered to support the claim, and the warrant.

The warrant is the assumption on which the claim and the evidence depend. Another way of saying this would be that the warrant explains why the data supports the claim. For example, suppose you see a one of those commercials for a product that promises to give you whiter teeth. Here are the basic parts of the argument behind the commercial:

Claim	You should buy our tooth-whitening product.
Data	Studies show that teeth are 50% whiter after using the product for a specified time.
Warrant	People want whiter teeth.

Notice that those commercials 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.

Now that you're familiar with the three main parts of an argument, let's look at three other elements Toulmin identified.

Qualifier	A qualifier is a statement about how strong the claim is. For example, if you are claiming that stains on teeth are caused by drinking coffee, you might need to acknowledge that there may be other causes as well. Your qualified claim would be that drinking coffee is the most significant cause (although perhaps not the only cause) of stained teeth.
Rebuttal	A rebuttal is an exception to your claim. For example, you might have to acknowledge that a certain kind of coffee does not stain teeth. Your claim, however, would be that coffee is the major cause of stained teeth except for those coffee drinkers who drink the special non-teeth staining coffee.
Backing	Sometimes the warrant is an important part of the argument. Additionally, sometimes the warrant is not broadly understood or broadly accepted. In this case, a speaker or writer may have to defend the warrant. In our example, the warrant would need to be backed by reasons such as the argument that whiter teeth will help you get more dates or that whiter teeth will make you look better in yearbook photos. Reasons that support the warrant are called backing.

So--how do you make this model work for you?

Have you ever noticed that when you research both sides of a question, you find yourself being convinced first by one side, and then by the other? Each argument sounds good--at least while you are reading it. When you read an argument which takes an opposite position--that sounds good too, and soon you may feel completely confused.

Toulmin to the rescue! By identifying the parts of an argument so each can be evaluated separately, Toulmin created a very useful model for analyzing the validity of an argument. Submit each source you study to rigorous Toulmin analysis. Identify each argument's claims, data, and warrants. Look for qualifiers, rebuttals, and backing for the warrants. Compare one claim with another. Compare data between the two arguments. Compare warrants and their backing, qualifiers, and rebuttals. By analyzing the separate parts of an argument, you'll be much better equipped to evaluate each argument's validity. Then, as you begin to write, use Toulmin's methods to submit your own argument to the same rigorous analysis.

Use this worksheet in MS Word or rich text format as a guide to using Toulmin's model to question and evaluate your research sources.

Links to Other Resources

• Stephen Toulmin (brief biography)
• The Toulmin Project Home Page
• Toulmin Argument

Toulmin Logic Worksheet (doc file)
Use this worksheet to create and assess arguments.

doc file: You need the Microsoft Word program, a free Microsoft Word viewer, or a program that can import Word files in order to view this file. To learn more about the free Microsoft Word Viewer, visit the Microsoft Word website.

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