Rulebook For Arguments, A

A Rulebookfor
A rguments

Anthony Weston

A Rulebookfor
A rguments
T hird Edition

Hackett Publishing Company
Indianapolis/Cambridge

Third edition copyright © 2000 by Anthony Weston

All rights reserved
Printed in the United States of America
06 05 04 03 02 01 00

12 3 4 5 6 7

For further information, please address:
Hackett Publishing Company, Inc.
P.O. Box 44937Indianapolis, IN 46244-0937
www.hackettpublishing.com

Cover and interior design by Abigail Coyle
Cover photograph: www.comstock.com

Library of Congress Cataloging-in-Publication Data
Weston, Anthony, 1954—
A rulebook for arguments / Anthony Weston.—3rd ed.
p. cm.
Includes bibliographical references.
ISBN 0-87220-553-3 (cloth)—ISBN 0-87220-552-5 (paper)
1 . Reasoning. 2. Logic. 3. Englishlanguage—Rhetoric. I. Title.
BC177 .W47 2000
168—dc21
00-058121

Contents

Preface

ix

Introduction

xi

I. Composing a Short Argument:
Some General Rules

1

1.
2.
3.
4.
5.
6.
7.

Distinguish premises and conclusion
Present your ideas in a natural order
Startfromreliable premises
Be concrete and concise
Avoid loaded language
Use consistent terms
Stick to onemeaning for each term

1
3
4
5
6
7
8

II. Arguments by Example

10

8.
9.
10.
1 1.

11
12
14
17

Give more than one example
Use representative examples
Background information is crucial
Consider counterexamples
v

A Rulebookfor Arguments

VI

III. Arguments by Analogy

19

1 2. Analogy requires a relevantly similar example

21

IV. Arguments from Authority24

1 3.
1 4.
1 5.
16.
17.

25
26
28
30
30

Sources should be cited
Seek informed sources
Seek impartial sources
Cross-check sources
Personal attacks do not disqualify a source

V. Arguments about Causes

32

18.
19.
20.
2 1.
2 2.

Explain how cause leads to effect
Propose the most likely cause
Correlated events are not necessarily related
Correlated events mayhave a common cause
Either of two correlated events may cause
the other
2 3. Causes may be complex

33
35
36
36

VI. Deductive Arguments

40

2 4.
2 5.
26.
27.
28.
29.
30.

41
42
44
46
47
48
50

Modus Ponens
Modus Tollens
Hypothetical Syllogism
Disjunctive Syllogism
Dilemma
Reductio ad absurdum
Deductive arguments in several steps

38
38

VII. Composing anArgumentative Essay
A. Exploring the Issue

53

A l. Explore the arguments on all sides of the issue
A2. Question and defend each argument's premises
A3. Revise and rethink arguments as they emerge

54
56
57

Contents

vu

VIII. Composing an Argumentative Essay
B . Main Points of the Essay

59

Bl.
B 2.
B 3.
B 4.
B 5.

59
60
61
62
63

Explain the question
Makea definite claim or proposal
Develop your arguments fully
Consider objections
Consider alternatives

IX. Composing an Argumentative Essay
C. Writing

64

CI.
C2.
C3.
C4.
C5.
C6.

64
65
65
67
68
69

Follow your outline
Keep the introduction brief
Give your arguments one at a time
Clarify, clarify, clarify
Support objections with arguments
Don't claim more than you haveshown

X. Fallacies
The Two Great Fallacies
Some Classical Fallacies

71
71
73

Appendix: Definition

79

D l. When terms are unclear, get specific
D2. When terms are contested, work from the
clear cases
D3. Don't expect definitions to do the work
of arguments

80
82

Next Steps

86

84

Preface

This book is a brief introduction to the art of writing and assessingarguments. It sticks to the bare essentials. I have found that
students and writers often need just such a list of reminders and
rules, not lengthy introductory explanations. Thus, unlike most
textbooks in argumentative writing or "informal logic," this
book is organized around specific rules, illustrated and explained soundly but above all briefly. It is not a textbook but a
rulebook....