EN101
THE TOULMIN METHOD:
A MODERN VARIANT OF FORMAL LOGIC
Stephen Toulmin
• British philosopher and educator
• Toulmin believed that for an argument to succeed, it
needs to provide justification for a claim. This, he
believed, will ensure it stands up to criticism and earns a
favorable verdict.
• According to the Toulmin model, a claim is linked to its
support through what is called a warrant.
• A claim’s warrant indicates how one gets from factual
support (which Toulmin calls data) to the claim.
Defining Some Terms
• Claim – is a sentence that asserts something that may be
true or false and so needs support: The world is warming
up. This is the best English class. Twinkies taste good.
• Data or Reason – is a sentence supporting your claim,
main or not. It is generally triggered by the word
because: Twinkies taste good because they have cream
filling.
• Warrant – what connects or bridges the data to the
reason. You might consider renaming this the “necessary
assumption.”
An Argument
Brand A peanut butter has been proven to be healthier
than Brand B. Furthermore, most children prefer the taste
of Brand A to that of Brand B. Therefore, parents should
choose Brand A over Brand B.
This seems like a fair argument on the surface. But is the person, who is
claiming that peanut butter A is better than peanut B, assuming anything
to reach his/her conclusion?
Sound Arguments as Buildings
Diagrammed
Therefore, parents should choose Brand
A over Brand B.
Brand A peanut
butter has been
proven to be
healthier
than Brand B.
Furthermore,
most children
prefer the taste
of Brand A to
that of Brand B.
Parents should choose products that
are healthier and taste better.
Revised Argument
Brand A peanut butter has been proven to be healthier
than Brand B. Furthermore, most children prefer the taste
of Brand A to that of Brand B. Parents should choose
products that are healthier and taste better. Therefore,
parents should choose Brand A over Brand B.
Another Argument
Environmentalist: When bacteria degrade household
cleaning products, vapors that are toxic to humans are
produced. Unfortunately, household cleaning products are
often found in landfills. Thus, the common practice of
converting landfills into public parks is damaging to human
health.
The correct assumption?
Environmentalist: When bacteria degrade household cleaning
products, vapors that are toxic to humans are produced.
Unfortunately, household cleaning products are often found in
landfills. Thus, the common practice of converting landfills into public
parks is damaging to human health.
a. In at least some landfills that have been converted into public parks there
are bacteria that degrade household cleaning products.
b. Converting a landfill into a public park will cause no damage to human
health unless toxic vapors are produced.
c. If a practice involves the exposure of humans to vapors from household
cleaning products, then it causes at least some damage to human health.
d. When landfills are converted to public parks, measures could be taken that
would prevent people using the parks from being exposed to toxic vapors.
e. If vapors toxic to humans are produced by the degradation of household
cleaning products by bacteria in any landfill, then the health of at least
some humans will suffer.
Diagrammed
Thus, the common practice of
converting landfills into public parks is
damaging to human health.
When bacteria degrade
household cleaning products,
vapors that are toxic to
humans are produced.
Unfortunately,
household cleaning
products are often
found in landfills.
In at least some landfills that have been converted
into public parks there are bacteria that degrade
household cleaning products.
A Diagrammed Example
A junior-year-abroadprogram will help the
department establish
international
connections. (Data)
My college major should
start a junior-year-abroad
program. (Claim)
International connections would be
valuable to my college. (Warrant)
Another Diagrammed Example
While the team has
potential, it lacks
maturity and depth.
(Data)
The Washington Wizards
are not good enough to
make the playoffs. (Claim)
Maturity and depth are required
attributes of a playoff team. (Warrant)
Warrants
• At the moment, this is all we need to be concerned with.
• So, the warrant or the necessary assumption is what connects
the data to the claim.
• Another way to remember the warrant is to picture:
• But, more specifically, picture the following:
Data (Reason)
Claim
Warrant
In-class and next class
• Finish the following warrant worksheet. Read the claims and
data carefully. Don’t make unwarranted assumptions based on
clichéd arguments or emotion. Reason well.
• Essay 1 rough draft is due Monday, August 1.
• Bring 2 hard copies of at least 1-2 double spaced pages.