Table Of ContentChristopher Hughes
ON A COMPLEX THEORY
OF A SIMPLE GOD
An Investigation in Aquinas'
Philosophical Theology
Cornell University Press, Ithaca and London
Copyright © 1989 by Cornell University
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First published 1989 by Cornell University Press.
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Contents
Preface IX
Abbreviatiolls XI
PART I. THE COD OF THE PHILOSOPHERS
Diville Simplicity: God alld His Existellce 3
Types of Divine Simplicity }
Form and Existence 5
Arc Properties Individualized Particulars? 10
Varieties of Esse 21
Five Arguments for the Identity of God with His Existence 28
Types of Priority }D
From the Posteriority of Composita to Divine Incomposition J]
Other Arguments for Divine Incomposition J6
From God's Nonpotentiality to the Identity of God with His
Existence 4J
The Argument from Participation 50
The Argument from God's Uncauscdness 54
The Argument from Characteristic Effects 56
2 Diville Simplicity: God alld His Attribllles 60
The Identity of Divine Attributes 60
Insular Attributes 6}
The Problem of Shared Attributes 67
Identity and Supervenience 71
Supervenience and Simplicity 8)
viii J Contents
3 Diville Simplicily: God alld His Naillre 88
Immateriality and the Relation of a Thing to Its Essence 88
God and His Essence 96
4 Kllowle~~e, COlllill<~ell(y, ami Challge ill God 107
Intrinsic and Extrinsic 107
Eternity "4
Omniscience and Immutability 120
Timelessness and Opcnness 127
Looking Back '49
PART II. THE GOD OF FAITH
5 Is Ihe Doctrille of the Trillity IIICOllsistellt?
153
The Apparent Inconsistency 153
Relative Identity? 156
Different Kinds of Difference? 162
Anselm's Nile 166
Types orCa-composition 170
Co-composition and the Trinity 176
Composition:tl and Noncompositiol131 Accounts of the
Trinity 18)
6 /delllily alld Ihe Trillily
One God and Three Persons 188
Three Hyposuscs of One Essence '92
Real Relations 194
Relations That Individuate? 197
Co-csscntial but Rclationally Distinct Individuals? 207
IJelll;tas S(;ClllldwII R£'Ill and Idcutitas Sauudum Ratiol/em 218
Identity Sc"md",11 Rem and Indisccrnibility 21)
Identity Secundum Rem as a Non-Euclidean Rc:lation? 2)0
Divine Simplicity and the Trinity 2)9
7 Cltatl. .~. e, Composition, aud tlte ltrcamaliou
The Union of Hum.:m and Divine Natures in Christ 24'
The Hypostatic Union and Composition 250
The Incarniltion ilnd Change Z5)
Alternatives to Aquinas' Account z6.,
COIlc/IISioll 269
Selected Bibliography 273
Index 277
Preface
For Aquinas, one and the same God may be characterized in two
very different ways. He is the simplest possible subsistent being,
identical to all of His parts, and to His (intrinsic) attributes, His
essence, and His existence. At the same time, He is three persons in
one nature, one of whom subsists in a human as well as in the divine
nature. In the first part of this book, I attempt to explicate Aquinas'
conception of divine simplicity; in the second, I attempt to explicate
his account of the Trinity and the Incarnation. I also try to determine
whether Aquinas' conception of divine simplicity and his accounts of
the Trinity and the Incarnation are individually and jointly workable.
This involves trying to answer the following questions: Could any
thing be simple in all the ways Aquinas thinks God is simple? Could
any being have the kind of metaphysical structure which for Aquinas
makes God triune? Could any being have the kind of relational prop
erty which for Aquinas makes God's Word incarnate? Could anything
as simple as Aquinas' God be three persons in one nature, one of
whom subsists in each of two natures? I argue that Aquinas' full
strength conception of divine simplicity is unworkable, although a
weakened and reconstructed conception may not be. Moreover, I
argue that because Aquinas' accounts of the Trinity and the Incarna
tion each presuppose the full-strength conception, they inherit its
unworkability. Finally, I address the question whether or not a recon
structed account of divine simplicity will mesh with anything like
Aquinas' account of the Trinity and Incarnation-or any other (ortho
dox) account thereof.
x I Preface
I am grateful to many friends and colleagues for criticism and
advice-among them Roy Endersby. Lily Knezevich. Shelly Kagan.
Richard Gale. Philip Quinn. Al Martinich. David Kaplan. Marilyn
McCord Adams. Eleonore Stump. Sydney Shoemaker. Robert Stal
naker. Richard Boyd. Richard Sorabji. Christopher Peacocke. and
Mario Mignucci. I am especially indebted to Gerald Massey. without
whose help and encouragement the dissertation that became this book
never would have been; to Norman Kretzmann. who-in spite of and
because of our disagreements over the distance between Athens and
Jerusalem-helped me greatly in turning the dissertation into a book;
and to William Alston. whose suggestions about how to turn this
book into a better one were very valuable (however well they were
implemented). These acknowledgments would be incomplete with
out mention of David Lewis. Although he has only rarely written on
philosophical theology. his ideas have had a considerable influence on
this book-and in particular. on those sections in which I attempt to
cross-pollinate medieval and contemporary ideas. Finally. I thank my
wife. Marcia. for her unfailing and loving support from the time I
began to think about Thomas Aquinas to the completion of this book.
and my daughters. Laura Kimi and Amanda. for their attempts to
"help Dada make book."
CHRISTOPHER HUGHES
Wimb/edoll, 1989
Abbreviations
CT Compttrdium tlreolo.l!iae
DE De eute et esseul;a
DP "De potentia"
DPN De principiis naturae
DSC "Dc spiritualibus crcaturis"
DUVI "Dc uniane verbi incarnati"
DV "De veritatc"
IPH 1" peri I,em,elleias
ME In duodeci", libros metaplrysicontm cxpositio
PE I" oclo libros physico",,,, expositio
QQ Quaestiones quodlibetales
SCG Summa contra Gemiles
SS Scriptum slIper libros sentemianm,
ST S,wuna tlreologiae
Unless stated otherwise, the translations provided in the text are my own,
although I am indebted to existing translations.
P I
ART
THE GOD OF THE
PHILOSOPHERS
[ I ]
Divine Simplicity:
God and His Existence
Types of Divine Simplicity
Of the properties ascribed to God in Aquinas' natural theology, we
may call one sort all/pliative, and one sort limitative. The ampliative
properties, which include knowledge, power, and goodness, are fa
miliar: they arc the (positive) perfections of God. The limitative prop
erties are less familiar and more problematic. They arc properties God
is said to have by virtue of not having certain kinds of (putative)
imperfections-where Aquinas' conception of imperfection includes
many properties that seem essential to any possible being. Among
those (putative) imperfections is composition: according to Aquinas,
God is incomposite in each of the following ways:
(.) He is not composed of extended parIS; hence He is not, and
docs not have, a body.
(2) He is not composed of substantial form-in virtue of which
He is the kind of thing He is-and form-receiving matter-in
virtue of which He is the particular thing He is. God is instead
pure self-subsistent form, devoid of matter of any kind.
(3) God is not 'composed· of act and potency. There is no distinc
tion in God between an element by virtue of which He has
certain potentialities. and an clement by virtue of which those
potentialities arc actualized. Consequently, God is entirely
immutable and atemporal.
(4) God is not composed of essence and anything disjoint from
that essence. While there is a ditTerence between .he individ-
