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 E N T H Y M E M E

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

PART TWO

In the 1950s, I rejected arguments

based on formal logic in favor of an

audience-based, courtroom model.

STEPHEN TOULMIN

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 Argumentgets 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

R E F U T A T I O N

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?