Synthetic Ethical Naturalism

291 Pages·2014·1.02 MB·English

by  Michael Rubin

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Open Access Dissertations
2-2009
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Michael Rubin
University of Massachusetts Amherst
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SYNTHETIC ETHICAL NATURALISM

A Dissertation Presented

by

MICHAEL RUBIN

Submitted to the Graduate School of the
University of Massachusetts Amherst in partial fulfillment
of the requirements for the degree of

DOCTOR OF PHILOSOPHY

February 2009

Philosophy
© Copyright by Michael Rubin 2009
All Rights Reserved
SYNTHETIC ETHICAL NATURALISM

A Dissertation Presented
by
MICHAEL RUBIN

Approved as to style and content by:

_____________________________________
Fred Feldman, Chair

_____________________________________
Phillip Bricker, Member

_____________________________________
Hilary Kornblith, Member

_____________________________________
Christopher Potts, Member

_______________________________________
Phillip Bricker, Department Head
Philosophy
DEDICATION

To my family: Linda, Michelle and Neil Rubin
ACKNOWLEDGEMENTS

In writing this dissertation, I have incurred a number of debts, not all of which are
financial. My greatest debt is to my dissertation director Fred Feldman. I am also
grateful to Hilary Kornblith, Jason Raibley, Lynne Rudder Baker, Jake Bridge, Phil
Bricker, Vere Chappell, Sam Cowling, Dan Doviak, Chris Heathwood, Kristen Hine,
Justin Klocksiem, Uri Leibowitz, Helen Majewski, Kris McDaniel, Kirk Michaelian,
Andrew Platt, Chris Potts, Alex Sarch, Kelly Trogdon, and Brandt Van der Gaast.
Material from chapters one and two appear in “Sound Intuitions on Moral Twin
Earth,” Philosophical Studies (2008) 139: 307-327. I thank Springer for permission to
reprint that material here. Chapter five is published as “Is Goodness a Homeostatic
Property Cluster?” (2008) Ethics 118: 496-528. I thank the University of Chicago Press for
permission to reprint that material here. I am grateful to anonymous referees from both
journals for helpful comments.

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ABSTRACT
SYNTHETIC ETHICAL NATURALISM
FEBRUARY 2009
MICHAEL RUBIN, B.A., BOSTON UNIVERSITY
M.A., NEW YORK UNIVERSITY
Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST
Directed by: Professor Fred Feldman

This dissertation is a critique of synthetic ethical naturalism (SEN). SEN is a
view in metaethics that comprises three key theses: first, there are moral properties and
facts that are independent of the beliefs and attitudes of moral appraisers (moral realism);
second, moral properties and facts are identical to (or constituted only by) natural
properties and facts (ethical naturalism); and third, sentences used to assert identity or
constitution relations between moral and natural properties are expressions of synthetic, a
posteriori necessities. The last of these theses, which distinguishes SEN from other
forms of ethical naturalism, is supported by a fourth: the semantic contents of the central
moral predicates such as ‘morally right’ and ‘morally good’ are fixed in part by features
external to the minds of speakers (moral semantic externalism).
Chapter 1 introduces SEN and discusses the most common motivations for
accepting it. The next three chapters discuss the influential “Moral Twin Earth”
argument against moral semantic externalism. In Chapter 2, I defend this argument from
the charge that the thought experiment upon which it depends is defective. In Chapters 3
and 4, I consider two attempts to amend SEN so as to render it immune to the Moral
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Twin Earth argument. I show that each of these proposed amendments amounts to an
abandonment of SEN.
Chapter Five explores Richard Boyd’s proposal that moral goodness is a
“homeostatic property cluster.” If true, Boyd’s hypothesis could be used to support
several metaphysical, epistemological, and semantic claims made on behalf of SEN. I
advance three arguments against this account of moral goodness.
In the sixth chapter, I argue that moral facts are not needed in the best a posteriori
explanations of our moral beliefs and moral sensibility. Because of this, those who
accept a metaphysical naturalism ought to deny the existence of such facts or else accept
skepticism about moral knowledge. In Chapter 7, I consider a counterargument on behalf
of SEN to the effect that moral facts are needed in order to explain the predictive success
of our best moral theories. I show that this argument fails.
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TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS.................................................................................................v

ABSTRACT.......................................................................................................................vi

CHAPTER

1. MORAL REALISM, ETHICAL NATURALISM, AND THE NECESSARY A
POSTERIORI.................................................................................................................1

1.1. Introduction.....................................................................................................1
1.2. Moral Realism.................................................................................................4

1.2.1. Moral Realism and Moral Constructivism....................................4
1.2.2. The presumptive case for moral realism.......................................6

1.3. Naturalism: Metaphysical and Ethical............................................................9

1.3.1. Ethical naturalism.........................................................................9
1.3.2. Metaphysical naturalism.............................................................11

1.4. Analytic Ethical Naturalism..........................................................................12

1.4.1. The general strategy of analytic ethical naturalism....................12
1.4.2. Semantic assumptions of analytic ethical naturalism.................13
1.4.3. First-order normative ethics as conceptual analysis...................16

1.5. The Rejection of Realistic Analytic Ethical Naturalism...............................17

1.5.1. The rejection of analyticity.........................................................17
1.5.2. Doubts about descriptivism.........................................................18
1.5.3. The open question argument.......................................................19
1.5.4. Chauvinistic conceptual relativism.............................................21
1.5.5. The argument from normativity..................................................23
1.5.6. Analyticity and stance-independence.........................................25

1.6. Synthetic Ethical Naturalism........................................................................26

1.6.1. The necessary a posteriori..........................................................26
1.6.2. The semantic and metaphysical underpinnings of the necessary
a posteriori..................................................................................28
1.6.3. Causal theories of reference........................................................30
1.6.4. The epistemological commitments of SEN................................34
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1.7. How SEN answers the objections to AEN....................................................39

2. MORAL TWIN EARTH VERSUS EXTERNALIST MORAL SEMANTICS...........43

2.1. Introduction...................................................................................................43
2.2. Putnam’s Twin Earth....................................................................................44
2.3. Moral Twin Earth..........................................................................................47
2.4. The Attack on the Moral Twin Earth Thought Experiment..........................51

2.4.1. Introduction.................................................................................51
2.4.2. A preliminary objection..............................................................52
2.4.3. First objection: competing theories of a kind.............................55
2.4.4. First reply....................................................................................56
2.4.5. Second reply................................................................................57

2.5. Isolating Moral Properties.............................................................................60

2.5.1. Second objection.........................................................................60
2.5.2. Reply to (i)..................................................................................62
2.5.3. Reply to (ii).................................................................................63
2.5.4. Reply to (iii)................................................................................65

2.6. Functional and Non-Functional Kinds..........................................................68

2.6.1. Third objection............................................................................68
2.6.2. Reply...........................................................................................69

2.7. Conclusion....................................................................................................70

3. MORAL TWIN EARTH AND HIGHER-LEVEL PROPERTIES..............................72

3.1. Introduction...................................................................................................72
3.2. A Prelimary Sketch of the Higher-Level Properties Reply to Moral Twin
Earth..............................................................................................................73
3.3. Functionalism about Mental Properties........................................................75
3.4. The Higher-Level Properties Reply to MTE................................................78
3.5. Troubles for the Higher-Level Property Reply: Agent’s-Group Moral
Relativism.....................................................................................................81
3.6. “Merely Possible” Relativism.......................................................................84
3.7. Is Agent-Relativism Compatible With Moral Realism?...............................86
3.8. Conclusion....................................................................................................93

4. BRINK’S MORAL SEMANTICS...............................................................................94

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