Toulmin In the 1950s Stephen Toulmin rejected formal logic models

Toulmin Arguments
In the 1950s Stephen Toulmin rejected formal logic models in favor of an
audience-based courtroom model.
How it differs from the Aristotelian syllogistic model:
1) It assumes that all assertions and assumptions are contestable by
"opposing counsel"
2) It assumes that all final "verdicts" about the persuasiveness of the
opposing arguments will be rendered by a neutral third party, a judge
or a jury.
One key point is that you make your argument appeals to those who don't
already hold your point of view--preaching to the choir.
Initial enthymeme: Cocaine and heroin should be legalized because
legalization would eliminate the black market in drugs.
Claim: Cocaine and heroin should be legalized.
Stated Reason: because legalization would eliminate the black market in
Unstated Assumption: The black market is bad.
Warrant: Black markets are harmful to society.
The warrant is the value, belief, or principle that must appeal to your
In addition, Toulmin says our arguments need grounds = supporting
evidence that cause you to make a claim--facts, data, statistics, testimony,
examples--and backing = arguments that support your warrant.
Example of Grounds:
Legalizing alcohol after Prohibition eliminated the black market for alcohol
in this country.
Example of Backing:
The Black market in drugs increases the crime rate. Black markets enable
criminals to make money off of addicts. Black market drugs are often
unsafe as no one inspects the ingredients.
Toulmin also suggests that we anticipate how a resistant audience would try to
refute our argument:
Conditions of Rebuttal:
a) They could attack our reason and grounds ex. argue that legalizing drugs
wouldn't end black market.
b) They could attack our warrant and backing ex. argue that the negative
consequences of legalizing drugs would outweigh the benefits.
Conditions of rebuttal are often stated as conditionals beginning with the word
a) Legalizing cocaine and heroin would eliminate the black market in drugs
unless taxes on legal drugs kept the price high enough that a black market
would still exist. Or unless new kinds of illegal designer drugs were developed
and sold on the black market.
b) Ending the black market is good unless the increased numbers of drug users
and addicts were unacceptably high. Or unless harmful changes in social
structure due to the acceptance of drugs were too severe. Or unless the health
and economic consequences of increased numbers of drug users were
Toulmin's final term—qualifier—is used to limit the force of a claim and
indicate the degree of probable truth.
For example: Unless the social costs are too high, we should legalize drugs in
order to eliminate the ill effects of the black market in drugs.
Practice assignment: Work out the enthymeme, claim, stated reason, warrant,
ground, backing, qualifier, and conditions of rebuttal for the following
statement: Grades in college should be abolished.