Table Of ContentALEXW ORSNIP
Fitting Things Together
Fitting Things Together
Coherence and the Demands
of Structural Rationality
ALEX WORSNIP
1
3
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Library of Congress Cataloging-in-Publication Data
Names: Worsnip, Alex, author.
Title: Fitting things together : coherence and the demands of
structural rationality / Alex Worsnip.
Description: New York, NY, United States of America :
Oxford University Press, [2021] | Includes bibliographical references and index.
Identifiers: LCCN 2021031183 (print) | LCCN 2021031184 (ebook) |
ISBN 9780197608142 (hardback) | ISBN 9780197608159 (updf) |
ISBN 9780197608173 (oso) |ISBN 9780197608166 (epub)
Subjects: LCSH: Practical reason.
Classification: LCC BC177 .W67 2021 (print) |
LCC BC177 (ebook) | DDC 128/.33—dc23
LC record available at https://lccn.loc.gov/2021031183
LC ebook record available at https://lccn.loc.gov/2021031184
DOI: 10.1093/ oso/ 9780197608142.001.0001
1 3 5 7 9 8 6 4 2
Printed by Integrated Books International, United States of America
For Jess,
Without whom I would not fit together
Contents
Preface Lx
Acknowledgme11ts xv
PART 1 DUALISM ABOUT RATIONALITY
DEFENDED
3345
1. Getting Structural (Ir)ralionality into View
359
2. A Rough Account of SubstantiveR ationality
3. Eliminations and Reductions 1
4. Eliminations and Reductions 11
PART II A THEORY OF STRUCTURAL
RATIONALITY
5. Unifyingt he Lnstanceso f incoherence l27
6. Requirements ofStructurnl Rationality 165
7. Talk About Structural Rationality 196
8. The Normativity of Structural Rationallly 235
PART III DRAWING SOME LESSONS
9. Upshots for Other Debates 281
Coda: The Tyranny of Value 315
知jere,ICes 319
Ind扛 329
Preface
Wilfrid Sellars famously wrote that “the aim of philosophy, abstractly formu-
lated, is to understand how things in the broadest possible sense of the term
hang together in the broadest possible sense of the term.”1 This book is about
how a fairly specific kind of thing—n amely, attitudinal mental states such as
beliefs, credences, desires, intentions, preferences, hopes, and fears—h ang
(or don’t hang) together in a fairly specific sense, namely that of being co-
herent, or structurally rational.
Obviously, I’ll have much more to say about the notion of structural ra-
tionality in due course, and I’ll introduce some central examples in §1.1.
But, to give you some initial idea of what I mean, structural rationality (po-
tentially) includes things like intending the means to one’s ends, respecting
one’s own judgments about what one ought to do (and believe), having con-
sistent beliefs, having credences that obey the probability axioms, having
preferences that aren’t cyclical, and many other examples.
The primary aim of this book is to defend the view that structural ration-
ality is a genuine, autonomous, unified, and normatively significant phe-
nomenon. Let me briefly explain these claims in turn.
• When I say that it is genuine, I mean that being coherent genuinely
amounts to a kind of rationality (and that being incoherent genuinely
amounts to a kind of irrationality).
• When I say that it is autonomous, I mean that it is both distinct from
and not reducible to what I will call substantive rationality, or reasons-
responsiveness. According to me, structural and substantive ration-
ality are two distinct but equally genuine kinds of rationality, neither of
which can be explained in terms of the other. I call this part of my view
dualism about rationality.
• When I say that it is unified, I mean that there is something that unifies
the instances of coherence and that unifies the instances of incoherence.
1 Sellars (1963: 1).
x Preface
• And when I say that it is normatively significant, I mean (roughly) that
facts about the structural (ir)rationality of possible sets of attitudes bear
on whether we ought (not) to have, or do something that results in our
(not) having, those attitudes.
In arguing for these claims, I also offer a positive theory of structural ration-
ality: of the nature and form of its requirements, of the semantics of our talk
about it, of what unifies its instances, and of the way in which it is norma-
tively significant.
A further aim of the book is to explore the ways in which both dualism
about rationality and the specific theory of structural rationality that I defend
have tangible consequences for existing debates in (meta)ethics and episte-
mology. This book draws a lot of distinctions. Works like this one can feel
like they engage in distinction- mongering for its own sake, and the debates
of which they are part can seem only to concern how to chop up concepts.
I’ll try to show that, at least in this case, this is not so: the view I defend does
not leaves things as they were. It has ramifications for a wide range of philo-
sophical debates, including those about moral rationalism, neo-K antianism
in ethics, ideal attitudes accounts of reasons, rational choice theory in social
science, Bayesian conditionalization, higher-o rder evidence, the normativity
of logic, and epistemic permissivism.
There has been a recent spate of philosophical books on rationality2 (as
well as countless journal articles). Why yet another? To explain the need for
this book, I will take the opportunity to briefly situate my view in relation to
the existing literature about rationality.
Some literature on rationality proceeds without even considering the
possibility of distinguishing substantive and structural rationality, simply
employing an undifferentiated, monistic notion of rationality. Though this
sort of approach is becoming rarer, it persists in much of epistemology. Many
epistemologists take it to be a “truism” or a “platitude” that rationality, as it
applies in the doxastic domain, is concerned with one’s taking the doxastic
attitudes that one’s evidence supports: in other words, with responding
correctly to one’s evidential reasons.3 Indeed, more or less tacitly, they as-
sume that it is exclusively concerned with this. (In this respect, the episte-
mological literature contrasts sharply with the practical rationality literature,
2 E.g., Broome (2013), Kiesewetter (2017), Wedgwood (2017), Lord (2018), Henning (2018), and
Brunero (2020).
3 See, among many others, Williamson (2000: 164), Kelly (2006: §2), Cohen (2013: 99).
