Toulmin
developed his theory of argumentation because of what he viewed as an inherent
problem with formal logic. Put simply, Toulmin recognized what every person
should already know: Real people do not argue in syllogisms. You may remember
from a philosophy class that a syllogism is a form of logical argument.
According to rules of logic, if an audience accepts both the major and minor
premises of a syllogism, they must accept the conclusions. For instance, many
people are familiar with the following example of a syllogism:

• Major Premise: All men are mortal,
• Minor Premise: Socrates was a man,
• Conclusion: Socrates is mortal.

Toulmin
realized that this form of argumentation is not what one encounters when
listening to a public speech, arguing with a roommate about what music to
listen to, or talking politics at a bar. Consequently, Toulmin developed his
theory in order to explain how argumentation occurs in the natural process
of everyday argument. Consequently, Toulmin wanted to explain how real
people (not philosophers) argue.

Although
Toulmin’s position on formal logic — that formal rules of logic do not fit
well with common practices of argument — may seem obvious, one must remember
the time period in which Toulmin developed his theory. Students of public
speaking, rhetoric, and logic were only taught formal logic. Using a
contemporary example to illustrate: Students were taught how to program a
computer before they were taught how to click a mouse. When one recognizes the
traditions of the time period, Toulmin’s theory of argument seems even more
revolutionary.

The Toulmin Model of Argument-Basics

Claim

Think
of the claim in an argument as the most general statement in the
argument. It may not be a particularly general statement all by itself,
and some claims for arguments are very narrow. But the claim in an
argument is like the umbrella statement that all other parts of an
argument have to fall under. If a reason (or evidence) doesn’t fall
under the umbrella of the claim, then it’s irrelevant.

Warrants

These are the assumptions or presuppositions underlying the argument.
Warrants are generally accepted beliefs and values, common ways our
culture or society views things; because they are so commonplace,
warrants are almost always unstated and implied. The author and
audience may either share these beliefs, or the author’s warrants may
be in conflict with audience’s generally held beliefs and cultural
norms and values. Warrants are important because they are the "common
ground" of author and audience; shared warrants invite the audience to
participate by unconsciously supplying part of the argument. Warrants
are also important because they provide the underlying reasons linking
the claim and the support. You can infer the warrants by asking,
"What’s causing the author to say the things s/he does?" or "Where’s
the author coming from?"

Data

Data is the information that generates the claim in theory. More often, it is searched for after the claim is provided.

• “the evidence, facts, data, and information that are the
  reason for the claim in the first place- a reasoned beginning” (Ross,
  1985).
• Data is significant because it establishes the
  basis of the argument. In effect, the data is the starting point from
  which all sound arguments must begin.
• Types of Data: Anecdotal, Testimony, Statistics

Rebuttal

The Rebuttal (or Reservation) is an exception to the claim presented by
the arguer. In Toulmin’s model, arguments are not considered to be true
without analysis. The rebuttal demonstrates how arguments can be
strengthened (and made more correct) by acknowledging the limits of the
argument.

Qualifier

The Qualifier is recognition of the rebuttal. After analyzing one’s
argument and acknowledging its limits, the rhetor should signify
his/her new statement with the qualifier statement. Qualifiers are
often words like

• Except
• Unless
• Other than

The Toulmin model is both a method of analyzing the argument of others
and developing the soundness of one’s own argument. A useful technique
to develop sound argument is to run one’s argument through the model
until the claim is true.