Counterfactuals E-Book

David Lewis

• Herausgeber: John Wiley & Sons
• Kategorie: Geisteswissenschaft
• Sprache: Englisch

Seitenzahl: 345

Veröffentlichungsjahr: 2013

Beschreibung

Counterfactuals is David Lewis' forceful presentation of and sustained argument for a particular view about propositions which express contrary to fact conditionals, including his famous defense of realism about possible worlds.

Leseprobe

Contents

Preface

Acknowledgements

1 An Analysis of Counterfactuals

1.1 Introduction

1.2 Strict Conditionals

1.3 Variably Strict Conditionals

1.4 The Limit Assumption

1.5 ‘Might’ Counterfactuals and Outer Modalities

1.6 Impossible Antecedents

1.7 True Antecedents

1.8 Counterfactual Fallacies

1.9 Potentialities

2. Reformulations

2.1 Multiple Modalities

2.2 Propositional Quantification

2.3 Comparative Similarity

2.4 Similarity Measures

2.5 Comparative Possibility

2.6 Cotenability

2.7 Selection Functions

2.8 The Selection Operator

3. Comparisons

3.1 The Metalinguistic Theory: Implicit Premises

3.2 The Metalinguistic Theory: Factual Premises

3.3 The Metalinguistic Theory: Laws of Nature

3.4 Stalnakefs Theory

4. Foundations

4.1 Possible Worlds

4.2 Similarity

5. ANALOGIES

5.1 Conditional Obligation

5.2 ‘When Next’ and ‘When Last’

5.3 Contextually Definite Descriptions

6. LOGICS

6.1 Completeness Results

6.2 Decidability Results

6.3 Derived hlodal Logics

Appendix: Related Writings by David Lewis

Index

© 1973 by David Lewis

BLACKWELL PUBLISHING

350 Main Street, Malden, MA 02148-5020, USA

108 Cowley Road, Oxford OX4 1JF, UK

550 Swanston Street, Carlton, Victoria 3053, Australia

The right of David Lewis to be identified as the Author of this Work has been asserted in accordance with the UK Copyright, Designs, and Patents Act 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs, and Patents Act 1988, without the prior permission of the publisher.

First published by Basil Blackwell Ltd 1973

First publishing in the USA by Harvard University Press 1973

Reissued by Blackwell Publishers 2001

Reprinted 2003, 2005

Library of Congress Cataloging-in-Publication Data

Lewis, David K., 1941-

Counterfactuals / David Lewis.

p. cm.

First published: 1973.

Includes bibliographical references and index.

ISBN 0–631–22495–5 (hardback.: alk. paper) — ISBN 0–631–22425–4 (pbk. : alk. paper)

1. Counterfactuals (Logic) I. Title.

BC199.C66 L48 2000

160—dc21

00-059899

A catalogue record for this title is available from the British Library.

The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp processed using acid-free and elementary chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards.

For further information on

Blackwell Publishing, visit our website:

www.blackwellpublishing.com

IN MEMORY OF RICHARD MONTAGUE

Preface

The principal changes in this revised printing are in Section 6.1, where I have corrected two major errors in my discussion of completeness results for the V-logics. Both of them were spotted by Erik C. W. Krabbe in 1976. I am most grateful to him for finding the trouble, and also for very helpful correspondence about alternative methods of repair. One error was in my construction of the canonical basis on pages 127–130: I falsely claimed that the set of co-spheres of cuts around a given index would be closed under unions.* In order to ensure such closure, it is necessary to construct the canonical basis differently. The other was in the axiom system for VC given on page 132. I left out the rule of Interchange of Logical Equivalents; however I tacitly appealed to this rule in proving completeness, so my proof did not apply to the axiom system I had given.

In addition I have corrected minor errors on pages 35, 55 and 129, also spotted by Krabbe; removed misprints; and brought some references up to date.

I have had more to say about counterfactuals and related matters. These further thoughts might appropriately have been added to this book; but since they are to be found elsewhere, I have been content to add an appendix giving citations and abstracts.

David Lewis1986

* Erik C. W. Krabbe, ‘Note on a Completeness Theorem in the Theory of Counterfactuals’, Journal of Philosophical Logic7 (1978): 91–93.

Acknowledgements

I am grateful to Kit Fine, Hans Kamp, David Kaplan, Richard Montague, J. Howard Sobel, Robert Stalnaker, Richmond Thomason, and many other friends and colleagues for encouragement and for valuable discussions about counterfactuals over the last five years.

I am grateful also to the American Council of Learned Societies for financial assistance, and to Saint Catherine’s College, Oxford, for hospitality, during the year when most of this book was written.

David Lewis

Princeton, June 1972

1. An Analysis of Counterfactuals

1.1 Introduction

‘If kangaroos had no tails, they would topple over’ seems to me to mean something like this: in any possible state of affairs in which kangaroos have no tails, and which resembles our actual state of affairs as much as kangaroos having no tails permits it to, the kangaroos topple over. I shall give a general analysis of counterfactual conditionals along these lines.

My methods are those of much recent work in possible-world semantics for intensional logic.* I shall introduce a pair of counterfactual conditional operators intended to correspond to the various counterfactual conditional constructions of ordinary language; and I shall interpret these operators by saying how the truth value at a given possible world of a counterfactual conditional is to depend on the truth values at various possible worlds of its antecedent and consequent.

Counterfactuals are notoriously vague. That does not mean that we cannot give a clear account of their truth conditions. It does mean that such an account must either be stated in vague terms—which does not mean ill-understood terms—or be made relative to some parameter that is fixed only within rough limits on any given occasion of language use. It is to be hoped that this imperfectly fixed parameter is a familiar one that we would be stuck with whether or not we used it in the analysis of counterfactuals; and so it will be. It will be a relation of comparative similarity.

Let us employ a language containing these two counterfactual conditional operators:

read as ‘If it were the case that ___, then it would be the case that…’, and

read as ‘If it were the case that ___, then it might be the case that...’.For instance, the two sentences below would be symbolized as shown.

If Otto behaved himself, he would be ignored.

Otto behaves himselfOtto is ignored

If Otto were ignored, he might behave himself.

Otto is ignored Otto behaves himself

There is to be no prohibition against embedding counterfactual conditionals within other counterfactual conditionals. A sentence of such a form as this.

will be perfectly well formed and will be assigned truth conditions, although doubtless it would be such a confusing sentence that we never would have occasion to utter it.

The two counterfactual operators are to be interdefinable as follows.

Thus we can take either one as primitive. Its interpretation determines the interpretation of the other. I shall take the ‘would’ counterfactual as primitive.

Other operators can be introduced into our language by definition in terms of the counterfactual operators, and it will prove useful to do so. Certain modal operators will be thus introduced in Sections 1.5 and 1.7; modified versions of the counterfactual in Section 1.6; and ‘comparative possibility’ operators in Section 2.5.