Table Of ContentSubsistent Parts
Aquinas on the Hybridism of Human Souls
Eduardo Isdra Záchia
Thesis submitted to the
Faculty of Graduate and Postdoctoral Studies
In partial fulfilment of the requirements
For the Ph.D. degree in Philosophy
Department of Philosophy
Faculty of Arts
University of Ottawa
© Eduardo Isdra Záchia, Ottawa, Canada, 2013
To the memory of Balthazar Barbosa Filho,
who first inspired me to pursue this path.
ii
Table of Contents
Dedication ii
Abbreviations v
Abstract/Résumé vi
Acknowledgements vii
Introduction viii
PART 1. THE ELEMENTS OF AQUINAS’ TWOFOLD ACCOUNT OF THE HUMAN SOUL 1
SECTION 1. THE SOUL’S INHERENCE IN THE BODY
1. Gesturing Towards the Theory: Soul as Actuality 2
1.1. A First Approach: The Prologue of ST 1a Q75 2
1.2. The Soul as a Body: The Presocratic Mistake 6
1.3. The Soul as the Actuality of the Body 10
2. Specifying the Theory: Soul as Substantial Form 19
2.1. From Actuality to Form 19
2.2. Form as an Inherent Principle 28
2.3. Against Non-Hylomorphic Models 33
SECTION 2. THE HUMAN SOUL’S INDEPENDENCE FROM THE BODY
3. From Immateriality to Subsistence 42
3.1. Subsistence and the Criteria for Substancehood 44
3.2. The Soul as the Principle of Intellectual Operation 48
3.3. Two Senses of Immateriality and the Intellect’s Absolute Universality 54
3.4. On Proving Subsistence in Two Ways 63
3.5. The Human Soul as a Subsistent Part 67
3.6. A Taxonomy of Parthood: The Soul as a Metaphysical Part 73
3.7. Metaphysical Parts and the Definition of the Individual as Such 78
4. From Subsistence to Incorruptibility 86
4.1. The Hybrid Nature of the Human Soul Under Scrutiny 87
4.2. The Soul as Incorruptible Form: Reception and Transmission of Being 98
4.3. On Creating Human Souls 108
PART 2. AQUINAS’ ACCOUNT WITHIN THE CONTEMPORARY TRADITION 129
5. The Concreteness of Form & The Subsistent Soul 130
5.1. Kenny’s Argument: the Soul as an ‘Abstract Doer’ 130
5.2. The ‘Saint Louis’ Conception of Forms 137
5.3. Understanding Substantial Forms 152
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6. Alternative Attempts to Save Aquinas’ Account 168
6.1. Abel’s Substantializing Approach: A Poorer Ontology 169
6.2. Klima’s Minimalistic Account of Aquinas’ Hybrid Anthropology 176
6.3. Cross’ Response to Kenny and the Undesirable Possibility 183
6.4. Fortified Abstracts: Leftow on Thomistic Souls 189
7. From Subsistent Parts to Part-Dualism 199
7.1. Subsistent Souls & Substance-Dualism 200
7.2. Against Stump’s Compatibility Theory 215
7.3. Introducing Part-Dualism 224
7.4. Part-Dualism, Types of Constitution & Personal Persistence 232
Conclusion 240
Bibliography 248
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Abbreviations
For Aquinas:
CBT Commentary on Boethius’ De Trinitate
CDA Commentary on Aristotle’s De Anima
CM Commentary on Aristotle’s Metaphysics
CPA Commentary on Aristotle’s Posterior Analytics
CS Commentary on the Sentences of Peter Lombard
CT Compendium of Theology
DEE De Ente et Essentia
DME De Mixtione Elementorum
In 1 Cor. Commentary on Saint Paul’s First Epistle to the Corinthians
QDA Quaestiones de Anima
QDPD Quaestiones Disputatae de Potentia Dei
QDSC Quaestio Disputata de Spiritualibus Creaturis
QQ Quaestiones de Quodlibet
SCG Summa Contra Gentiles
ST Summa Theologiae
TSS Treatise on Separate Substances
For Aristotle:
Cat. Categories
DA De Anima
DGC De Generatione et Corruptione
Met. Metaphysics
PA Posterior Analytics
Phy. Physics
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Abstract/Résumé
In this dissertation I argue for the philosophical consistency of Aquinas’ hybrid view of human
souls - that is, the idea that human souls, and only human souls, are at once substantial forms
and subsistent things. I contend that the best way to understand the ontological status of
human souls according to Aquinas is by means of the concept of ‘subsistent parts’. Since
Aquinas characterizes souls as parts of substances, I propose a mereological analysis of the
different types of part in Aquinas, and I conclude that souls should be seen as metaphysical
parts of substances. An influential contemporary view holds that Aquinas’ doctrine is
inconsistent on the grounds that nothing could be an abstract (form) and a concrete (subsistent)
at the same time. I respond to this view by denying the widespread notion that substantial
forms are purely abstract entities. I hold that the best way to make sense of Aquinas’ twofold
approach to human souls is by saying that substantial forms possess an element of
concreteness which is accounted for by the fundamental relationship between form and being.
Finally, I address the question of taxonomy: how can we classify Aquinas’ view of the soul-
body relation in light of the concepts that are currently used in philosophy of mind. I argue
that the notion of a subsistent part entails the concept of ‘part-dualism’, which I present as
standing midway between substance-dualism and nonreductive materialism, and also as being
ontologically richer than property-dualism. I conclude this dissertation with a refutation of the
idea championed by some prominent scholars that the existence of the soul is sufficient for the
existence of the person.
***
Dans cette thèse, j’argumente en faveur de la consistance philosophique de la position hybride
défendue par Thomas d’Aquin sur l’âme humaine - c’est-à-dire, l’idée que les âmes humaines
sont à la fois des formes substantielles et des choses subsistantes. Je soutiens que la meilleure
façon de comprendre le statut ontologique des âmes humaines selon saint Thomas, c’est par la
notion de partie subsistante. Lorsque saint Thomas caractérise les âmes comme des parties des
substances, je propose une analyse méréologique des types distincts de partie selon Thomas
d’Aquin, d’où je conclus que les âmes doivent être conçues comme des parties métaphysiques
des substances. D’après une interprétation contemporaine influente, la position thomiste est
inconsistante car rien ne peut pas être à la fois une chose abstraite (une forme) et une chose
concrète (un être subsistant). Je réagis à cette interprétation en récusant la notion très
répandue que les formes substantielles sont des choses purement abstraites. J’affirme qu’on
doit comprendre l’explication double de Thomas d’Aquin sur l’âme humaine en disant que
toutes les formes substantielles possèdent un élément de concrétude qui est expliqué par le
rapport fondamental qui existe entre les concepts de forme et d’étant. Finalement, j’aborde le
problème de la taxonomie: comment doit-on classifier la conception thomiste du rapport entre
l’âme et le corps à la lumière des concepts qui sont utilisés actuellement par la philosophie de
l'esprit. Je maintiens que la notion de partie subsistante implique le concept de dualisme de
partie, que je présente comme étant à mi-chemin entre le dualisme de substance et le
matérialisme non-réductionniste, et aussi comme étant ontologiquement plus riche que le
dualisme de propriété. Je conclus la thèse avec une réfutation de l’idée défendue par des
commentateurs selon laquelle l’existence de l’âme est suffisante pour l’existence de la
personne.
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Acknowledgements
This work has been financially supported by the Brazilian National Council for
Scientific and Technological Development (CNPq), grant n. 200247/2008-5. I wish to
express my gratitude to Brazil’s Ministry of Science, Technology and Innovation, with
which CNPq is affiliated.
I want to say thank you to the administrative staff in the Philosophy department at the
University of Ottawa, and especially to Jocelyne Lacasse for her speedy solutions to
every practical difficulty I have encountered as a graduate student. I also thank Lise
Dazé at the FGPS for making things move quickly.
I offer very special thanks to my supervisor, Professor Antoine Côté, whose support
during my stay in Ottawa has been inexhaustible on all fronts. I thank him for his
guidance, and, above all, his friendship.
I thank my examiners, Fr. Lawrence Dewan, Francisco Gonzalez, Graeme Hunter, and
Scott MacDonald, for helping me make this a better thesis.
I would like to send a big thank you to my whole family in Brazil - specially to my
mom, Regina, and to my two younger sisters, Paula and Laura, whom I miss a lot.
I save the greatest thanks for my family here in Canada - my wife, Lívia, and my
daughter, Elisa - the light of my life. Their love and understanding is all I need to carry
on.
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Introduction
In this dissertation I examine Thomas Aquinas’ theory of the human soul. My goal is to
propose an interpretation of Aquinas’ account that shows the philosophical
consistency of his position. In order to do so, in the first part I explain what are the
key elements of Aquinas’ view, and I analyze the arguments that allow him to advance
his main theses. In the second part, I deal with some of the most influential treatments
of Aquinas’ anthropology in contemporary scholarship - some accusing Aquinas of
putting together an incompatible set of claims, others defending the consistency of his
view in ways that I do not consider fully satisfactory.
My primary purpose in the dissertation is to advance my own interpretation of
what I call Aquinas’ ‘hybrid’ - or ‘twofold’ - account of the human soul. I intend to
give a solution to the seeming inconsistency of Aquinas’ view that remains faithful to
the basic insights of his metaphysics, specially with respect to what he has to say about
the interaction between the concepts of form and being. At the same time, in the
manner of recent Thomistic scholarship, I wish to be able to address with my treatment
of Aquinas’ anthropology at least some of the concerns of contemporary philosophy of
mind.
What characterizes Aquinas’ twofold account of the human soul is the idea that
human souls, and only human souls, are at once substantial forms and subsistent
entities. Every soul, insofar as it is a soul, is a substantial form, which means that it is a
general property of souls that they exist in the portions of matter of which they are the
forms. Nevertheless, Aquinas also believes that, unlike other kinds of soul, the human
soul is capable of existing on its own; it is, in other words, a subsistent thing. The
challenge, therefore, consists in explaining how the human soul is capable of
independent existence when substantial forms are said to exist in the parcels of matter
that they inform.
The theory that human souls are subsistent substantial forms has received
different explanations. It is not uncommon to find scholars who claim that with the
death of the body the soul, because it subsists, becomes an unusual sort of substance.i
i This kind of account is proposed by Abel (1996). I take issue with his approach in chapter 6 (6.1).
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Since substantial forms are parts of substances, this would mean that when the body
ceases to exist the soul undergoes a transformation from part into whole. If one
follows this sort of approach, one has to admit that for Aquinas being a substance is a
necessary condition for having separate existence. However, in my view, when
adopting this reading one fails to grasp the complexity of Aquinas’ ontology, which I
claim makes room not only for subsistent substances and nonsubsistent parts of
substances, but also for subsistent parts of substances. Hence, one of the central
aspects of the view I want to defend in the dissertation is the notion that for Aquinas
human souls are subsistent parts of human composites. The consequence is that when
a soul ceases to exist in a body and starts to exist on its own it does not lose its status
as a part.
Another widespread interpretation of Aquinas’ twofold account is that the
human soul’s subsistence is an exception to a metaphysical rule that holds that to be a
form is to be enmattered. According to the scholars who adopt this strategy, even
though under normal conditions souls are said to exist in bodies, there is nothing
intrinsically wrong with the idea that under special circumstances a human soul may
exist without a human body.ii By contrast, the interpretation I develop throughout the
second part of this dissertation is that the best way to make sense of Aquinas’
philosophical anthropology is by viewing the subsistence of the human soul as
resulting from its nature as form. This approach, however, does not entail that every
form subsists simply by being a form. What it means is that a human soul subsists to
the extent that it is maximally a form. In order to advance the view that subsistence is
an effect of form, I need to do away with the notion that being a substantial form is
equivalent to being the configurational state of a parcel of matter.
The view I propose is that the human soul is a subsistent part of the human
substance. When claiming that the soul is not an unusual sort of substance but a part,
it is important to specify exactly what kind of part the soul is, given that Aquinas, like
most medieval thinkers, distinguishes between several types of wholes and parts. I
hold that the human soul stands to the ensouled body as a metaphysical part. Even
ii This is the position defended by a group of scholars whom I refer to as the ‘Saint Louis School’. I argue
against their reading of Aquinas in chapter 5.
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though the term ‘metaphysical part’ is not found in Aquinas’ texts, some expositors of
Aquinas’ philosophy claim that the term is able to capture what he has to say about the
role played by the soul in the composition of the human substance.iii
Anyone interested in studying Aquinas’ theory of the human soul must at some
point address the question of where to situate Aquinas in the contemporary debate
between dualists and materialists. Here the options are many. Some are led by the
idea that the soul, just like any substance, is said to exist on its own, and hold that
Aquinas must be seen as a bona fide substance-dualist, since the claim that the soul is
capable of outliving the body is in a way characteristic of substance-dualism. Others,
like Richard Swinburne, think that Aquinas is closer to what we nowadays call
‘property-dualism’, since in Swinburne’s view Thomistic souls are non-universal
properties of individual substances.iv Finally, we find those who want to claim that,
even though Aquinas explicitly endorses a theory of the soul’s subsistence, it is
possible to make his account of the soul-body relation compatible with nonreductive
versions of materialism. Scholars who defend this type of approach find support for
their view in the thesis that the soul is the substantial form of the body, and also in the
idea that what defines nonreductive materialism is the claim that mental states are
implemented in matter.v
In chapter 7 I examine each of these attempts, and I explain why I think they
are not successful. My strategy is to identify for each of the above categories a
foundational claim, and to show how those claims are incompatible with some
indispensable feature of Aquinas’ anthropology. I contend that in order to do justice to
Aquinas’ hybrid account of the human soul we need to introduce a new label, which I
call ‘part-dualism’. I present what I consider to be the main characteristics of part-
iii One prominent scholar who applies the notion of metaphysical part to Aquinas is Robert Pasnau. For
this, see Pasnau (2011), section 1.3. Note that since the terminology is recent, scholars still disagree as
to how to define metaphysical parts. In chapter 3, subsections 3.6 and 3.7, I present my own definition
of metaphysical parts, and I explain how it relates to the definition of the substance of which it is a part.
iv This position is developed in Swinburne (1997), ‘New Appendix C’, pp. 330-332.
v The first scholar to propose this kind of reading was Eleonore Stump. For her first attempt to describe
Aquinas as a soft materialist, see Stump (1995). For a revised version of the same ideas, see Stump
(2003), chapter 6.
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Description:Aquinas characterizes souls as parts of substances, I propose a . point address the question of where to situate Aquinas in the contemporary debate.