What do we mean by the
“logical structure”
of an argument?
PART ONE
We’ve discussed the following in
“academic” terms:
• The rhetorical triangle
• Argumentative Appeals: Logos, Ethos, Pathos
• Fallacies and booby traps
• Rogerian argument
In the “real” world, arguments are
grounded in beliefs
(rather than abstract, universal statements)
Usually these beliefs are unstated.
They are assumptions or implied.
And it isn’t a problem if the rhetor and
the audience share the beliefs.
But if they don’t…
Consider this scenario:
After-school jobs are bad for
teenagers because they take
away study time.
What is the unstated belief, or assumption, here?
Do you share this belief?
To make his argument successful,
the rhetor has to create an explicit
argument for the value of study time
instead of
leaving this crucial part of the
argument unstated and undeveloped.
I called the
argument that
depends on an
unstated belief,
or assumption, an
ENTHYMEME
ARISTOTLE
Technically, an ENTHYMEME is…
…an incomplete logical structure
that depends, for its completeness,
upon one or more unstated assumptions
(values, beliefs, principles)
that serve as the starting point of the
argument
An ENTHYMEME :
After-school jobs are bad for teenagers because
they take away study time is an enthymeme.
It combines a claim
[After-school jobs are bad for teenagers]
with a reason
[because they take away study time].
The unstated assumption:
LOSS OF STUDY TIME IS BAD
If your audience accepts the
enthymeme, no problemo.
If not,
then you must supply another
argument to support it,
until you find common ground with
your audience.
What’s the unstated assumption in this
enthymeme?
Cocaine and heroin should be legalized
because legalization would eliminate the
black market for drugs.
Eliminating the black market for drugs is good.
[Or, to state the assumption more fully, the benefits
of eliminating the black market in drugs far
outweighs the negative effects of legalizing drugs.]
The TOULMIN System
In the 1950s, I
rejected arguments
based on formal logic
in favor of an
audience-based,
courtroom model.
STEPHEN TOULMIN
PART TWO
Here’s how it differs:
(1) All assertions and assumptions are
contestable by “opposing counsel”
(2) All final “verdicts” will be rendered by a
neutral third party, a judge or jury
Here’s why it works:
1. It forces us to anticipate counterarguments
and to question our assumptions
2. It reminds us to answer opposing
arguments fully (and support our own with
reasons)
3. It reminds us not to construct an argument
that appeals only to those who already
agree with us.
Here’s the form, with some new
vocabulary:
ENTHYMEME After-school jobs are bad for
teenagers because they take away study time.
CLAIM After-school jobs are bad for teenagers
(A = C)
REASON because they take away study time
(B)
WARRANT Loss of study time is bad for teenagers
(B = C)
WARRANT = from “warranty” or
“guarantee”
The WARRANT refers to the unstated belief that
“guarantees” the validity of the argument.
Our beliefs (warrants)
are not enough…
…to flesh out our WARRANTS, we
need GROUNDS, or “evidence”
Here’s how this looks:
CLAIM After-school jobs are bad for teenagers
(A = C)
REASON because they take away study time
(B)
GROUNDS data and evidence show that after-school
jobs take away study time
(A = B)
WARRANT Loss of study time is bad for teenagers
(B = C)
If the audience accepts your WARRANT
already, then all you need is a CLAIM,
REASON, AND GROUNDS.
If they don’t accept your WARRANT, then
you’ll need some B A C K I N G.
B A C K I N G is the argument that
supports the WARRANT.
B A C K I N G answers the question, “How
do you know?”
The TOULMIN Argument
gets us thinking about where our
adversary might attack our argument…
Will he go after my
REASONS and
GROUNDS? Will
he go after my
WARRANT and
B A C K I N G?
When you know your adversary is
going to attack your argument, then
you must be ready for their
REFUTATION
A R E F U T A T I O N is the way to acknowledge the
exception(s) to the argument.
They often begin with the word, “unless.”
After-school jobs are bad for teenagers because
they take away study time
[HERE COMES THE REFUTATION]
UNLESS
it turns out that holding a job teaches teenagers to
manage their time more effective.
Toulmin’s LAST WORD
QUALIFIER.
These are words such as, “very likely” or
“probably” or “in many cases.”
We use QUALIFIERS to limit our CLAIMS.
In the real world, most arguments need to be
QUALIFIED, because they will certainly be
REFUTED.
In many cases, after-school jobs are bad for
teenagers because they take away study time
CLAIM: After-school jobs are bad for teens
QUALIFIER: In many cases
REASON: Jobs take away study time
GROUNDS: There are only so many hours in the day
WARRANT: Loss of study time is bad
BACKING: Data suggests that teens need to study
How would you REFUTE this argument?