Christopher 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 All rights reserved. Except for brief quotations in a review. this book. or parts thereof. must not be reproduced in any form without permission in writing from the publisher. For information. address Cornell University Press. 124 Roberts Place. Ithaca. New York 14850. First published 1989 by Cornell University Press. International Standard Book Number ().8014~1159-1 Library ofCongrcss Catalog Card Number 89-42877 Printed in the United Statcs of America UlJrariatlS: Library ofCo/l.~ress (atalo.i!i/l.~ j''.formatioll appears 011 tile last pa.~e of tile book. Ti,e paper it' tltis book is acid:free alld mats tile J!lIidelillfs for pemlO1If1Uf a"d ,J"rability Of tilt.' Commitlt'f Oil Productioll G"ideli,les for Book LOII.~ellily oJt/le COIItIClI Oil UI,rary Resources. iii mewory of my motllu 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-