## 1. Underlying Ideas



Reflection on the concept of an object has its first theoretical
articulation in Aristotle's *Categories*, where he
distinguishes between individual objects and the various kinds of
properties they can possess. He illustrates the various
categories:



> 
> each [individual term] signifies either substance or quantity or
> qualification or a relative or where or when or being in a position or
> having or doing or being affected. To give a rough idea, ideas of
> substance are man, horse; of quantity: four foot, five foot; of
> qualification; white, grammatical; of a relative: double, half,
> larger; of where: in the Lyceum, in the market-place; of when:
> yesterday, last year; of being in a position: is-lying, is-sitting; of
> having: has-shoes-on, has-armour-on; of doing: cutting, burning; of
> being-affected: being-cut, being-burnt. (1b25-2a4)
> 



The individual substances are the subjects of properties in the
various other categories, and they can gain and lose such properties
whilst themselves enduring. There is an important distinction pointed
out by Aristotle between *individual objects* and
*kinds* of individual objects. Thus, for some purposes,
discussion of substance is a discussion about individuals, and for
other purposes it is a discussion about universal concepts that
designate specific kinds of such individuals. In the
*Categories*, this distinction is marked by the terms
'primary substance' and 'secondary substance'.
Thus Fido the dog is a primary substance--an individual--but
*dog* or *doghood* is the secondary substance or
substantial *kind*. Each arm of this distinction raises
different issues. If one is concerned with *kinds of
substance*, one obvious question that will arise is 'what
makes something a thing of that kind (for example, what is involved in
being a dog)?' This is the question of the *essence* of
substantial kinds. But if one is concerned with individuals, the
parallel question is 'what makes something *that particular
individual* of a given kind (for example, what is involved in a
dog's being and remaining Fido)?' This is the question of
individual essences and of identity over time. Aristotle was mainly,
if not exclusively, concerned with questions of the first kind, but,
as we shall see in
 section 2.5.2
 and
 section 3,
 the latter question assumed a prominence later.



This association of *substance* with *kinds* carries
over into a use of the term, which is perhaps more scientific,
especially chemical, than philosophical. This is the conception
according to which substances are *kinds of stuff*. They are
not *individual objects* nor *kinds of individual
object*. Examples of this usage are *water*,
*hydrogen*, *copper*, *granite* or
*ectoplasm*.



There is a connotation of the word 'substance', reflected
in the sense of *substantial*, which signifies durability or
even permanence. Events, or Hume's impressions and ideas are
never substantial in this sense, because they are fleeting. Atoms,
fundamental kinds of stuff, gods, or abstract entities, such as
Platonic Forms or numbers, might be considered to be substantial to
the point of being indestructible or eternal: they last at least as
long as the world exists--and, in the case of gods or God, or
abstract entities, perhaps longer.



It seems, in summary, that there are at least six overlapping ideas
that contribute to the philosophical concept of substance. Substances
are typified as:


1. being ontologically basic--substances are the things from
which everything else is made or by which it is metaphysically
sustained;
2. being, at least compared to other things, relatively independent
and durable, and, perhaps, absolutely so;
3. being the paradigm subjects of predication and bearers of
properties;
4. being, at least for the more ordinary kinds of substance, the
subjects of change;
5. being typified by those things we normally classify as objects, or
kinds of objects;
6. being typified by kinds of stuff.



We shall see later that the Kantian tradition adds a seventh mark of
substance:


7. substances are those enduring particulars that give unity to our
spatio-temporal framework, and the individuation and re-identification
of which enables us to locate ourselves in that framework. (It should
be remarked in passing that at least one major expositor of Aristotle
(Irwin: 1988, especially chs 1, 9, 10) attributes a very similar
intention to Aristotle himself.)



In
 section 3.5
 we shall introduce a notion grounded in Aristotle's account,
but which has not naturally found a place in the earlier discussion,
namely the connection between substance and teleology. This can be
expressed as:


8. The substances in a given system are those entities crucial from
the teleological or design perspective of that system.
'Crucial' means that other things exist either to
constitute them or to provide a context of operations for them.



Different philosophers emphasise different criteria from amongst this
list, for reasons connected with their system as a whole. One could
plausibly say that an account is intuitively more appealing, the more
of the criteria it can find a place for. Probably, the Aristotelian
tradition comes nearest to doing this.


## 2. History of the Philosophical Debate on Substance



Almost all major philosophers have discussed the concept of substance
and an attempt to cover all of this history would be unwieldy. The
selection made will concentrate on those philosophers in whom the
broadly analytic tradition has shown most interest. First we shall
look at the development of the concept in the ancient world,
culminating in the work of Aristotle. His account dominated debate
through the Middle Ages and until the early modern period. We shall
consider various rationalist and empiricist treatments of the concept.
Locke's contribution will be considered in especial detail
because so much contemporary discussion is inspired (as we shall see
in
 section 3)
 by an Aristotle-Locke nexus.


### 2.1 Substance before Aristotle



Many of the pre-Socratic philosophers in fact had a concept of
substance rather like that above attributed to chemistry: that is,
their emphasis was on criterion (vi) above. They thought, that is,
that the being of the universe (hence they were pursuing substance in
sense (i)) consisted in some kind or kinds of stuff. Thales, for
example, thought that everything was essentially water, and Anaximenes
that everything was a form of air. For Anaximander, the
'stuff' in question was indeterminate, so that it could
transmute into the various determinate stuffs such as water, air earth
and fire. By contrast, atomists such as Democritus took those
determinate particular objects they called 'atoms' to be
the substance of the universe. Atoms are objects in our ordinary
sense, though they are not our ordinary objects: they are not dogs and
cats or tables and chairs. They are the subjects of predication, but
they do not change their intrinsic properties. Classical atoms are,
therefore, strong instances of (i) and (ii), but somewhat deviant
cases of (iii) and (v).



Plato rejected these materialist attempts to explain everything on the
basis of that of which it was made. According to Plato, the governing
principles were the intelligible Forms, which material objects
attempted to copy. These Forms are not substances in the sense of
being either the stuff or the individuals or the kinds of individuals
out of which all else is constructed. Rather they are the driving
principles that give structure and purpose to everything else. In
itself, the rest would be, at most, an unintelligible chaos. The Forms
meet criterion (i)--ontological basicness--but in a slightly
eccentric way, because they do not, in a normal sense, constitute
things. They meet (ii)--durability--in a strong fashion, for
they are eternal. They are not, in the intended senses, the subjects
of predication, and in no sense the subjects of change, so they do
badly on (iii) and (iv). They do not do well on (v) for they are not
individual things in any normal sense, though they are individuals, of
a very unusual kind. (Aristotle's main criticism of
Plato's Forms was that they are a bastard confusion of universal
and particular; see Fine 1993.) They are in no way kinds of stuff,
hence failing (vi). But failure to meet these standards is not
carelessness on Plato's part. It reflects his emphasis on
criterion (i), together with his particular view about the way in
which forms are basic.


### 2.2. Aristotle's account of substance



There are two main sources for Aristotle's approach to
substance, the *Categories* and *Metaphysics Z*. These
will be discussed in turn.


#### 2.2.1 Categories



Aristotle's account in *Categories* can, with some
oversimplification, be expressed as follows. The *primary
substances* are individual objects, and they can be contrasted
with everything else--secondary substances and all other
predicables--because they are not predicable of or attributable
to anything else. Thus, Fido is a primary substance, and
*dog*--the secondary substance--can be predicated of
him. *Fat*, *brown*, and *taller than Rover* are
also predicable of him, but in a rather different way from that in
which *dog* is. Aristotle distinguishes between two kinds of
predicables, namely those that are 'said of' objects and
those that are 'in' objects. The interpretation of these
expressions is, as usually with Aristotelian cruxes, very
controversial, but a useful way of looking at it is as follows.
*Dog* is *said of* Fido because it characterises him as
a whole. *Fat* and the others are described as *being
in* because they pick out a constituent feature that could be said
to be, in a logical though not a physical sense, part of, or
*in* him. Fido the individual is not attributable to any
further thing at all.



This account is intuitive, but perhaps it cannot be treated as a
formally adequate definition of the notion of primary substance or
individual. Fido the individual could be said to be *in* a
certain location and so attributed to something, namely a place. It is
natural to reply to this that an object is not an attribute of a place
in the same way as a property is an attribute of a thing: the property
is in a thing 'as a subject', but a place is not a subject
to which a thing is attributed: the place does not
'underlie' the thing as a thing 'underlies'
its properties. Although this may be true, it presupposes that we
already have a grasp on the sense in which properties belong to
objects and how this differs from the various ways that objects belong
to or can be attributed to things, and that we can call upon this
informal understanding in interpreting the theoretical account.
Whether this is legitimate might depend on what the objective is. If
the objective is to explain the difference between substance and
property in an entirely non-circular way by appealing to the fact that
properties are in substances but substances are not in things, this
would involve taking the notion of *being in* as primitive. If
we have to distinguish the sense in which properties are in substances
from the way in which substances can be in things--such as
places--before we can make the original point, then there has not
been a non-circular account. If, on the other hand, the objective is
simply to differentiate between concepts already in play, then
*Categories* achieves its objective.



Perhaps it is better, therefore, to see Aristotle in
*Categories* not as defining 'substance', so that
someone wholly lacking the concept might come to understand it, but as
exhibiting the marks and characteristics of a primitive concept on
which we have an intuitive grasp. If we understand his project in this
way, we can see Aristotle as presenting various marks of substance in
*Categories*. The marks of primary substance are:


1. Being objects of predication but not being themselves predicable
of anything else (at least, not in the way entities in the other
categories are: see the problem about attribution to location
above).
2. Being able to receive contraries (4 a10). A substance can go from
being hot to being cold, or from being red to being blue, but the
instance of blue in an object cannot similarly take on and lose a wide
range of attributes.
3. If substance did not exist it would be impossible for things in
any of the other categories to exist. There could be no instances of
properties if there were no substances to possess them.



But these criteria do not show why 'dog' is a secondary
substance term and 'brown thing' is not. So we need marks
for being a secondary substance, or substance *concept*. On
this he says two things.


4. "It is reasonable that, after the primary substances, their
species and genera should be the only other things called (secondary)
substance. For only they, of things predicated, reveal the primary
substance". (2 b28-30)
5. "Of the secondary substances the species is more a substance
than the genus, since it is nearer to the primary substance. For if
one is to say of the primary substance what it is, it will be more apt
to give the species than the genus". (2 b8-11)



The second of these two points is more uncontroversial than the first,
for it is indubitable that species terms focus more precisely on
particular things than generic terms. The first is, however, once
again intuitive but not compelling. It appeals to the fundamental
intuition that 'dog' tells you what Fido *is*
better than 'brown thing' does, but does not really give a
reason for this claim. Only in
 section 3.3,
 when we discuss Wiggins's theory, will we find more formal
reasons for treating species or sortal concepts as more revealing of
'what something really is' than are other terms.



The division between being *said of* and being
*in*--that is, between substance concepts and other
properties--seems intuitively clear enough until one remembers
that substance concepts are complex and are definable in terms of
other properties. Thus, 'man' is defined as
'featherless biped' or 'rational animal', and
it would seem that 'featherless', 'two-footed'
or 'rational' are properties and hence the kinds of things
that are *in* objects. Aristotle denies that this is so when
they enter into the definition of a substance. The features that
specifically make an object the kind of substance that it is, are
called *differentiae*, and Aristotle says



> 
> the differentia also is not in a subject. For footed and two-footed
> are said of man as subject, but are not in a subject; neither footed
> nor two-footed is *in* man. (3 a23-5)
> 



It would seem that these properties belong to objects in different
ways when they are part of a definition from when they are not. The
issue is what constitutes the unity of the species or secondary
substance: why is it not just a collection of properties and, if it is
just such a collection, why is it so different from any other
collection of properties? In order to begin to see how Aristotle
tackled this problem we need the apparatus of form and matter, which
does not appear in the *Categories*. (We will see when
discussing contemporary theories in
 section 3.1,
 however, that it is not clear that even now can we provide a wholly
non-circular account of substance.)


#### 2.2.2 Metaphysics



The *Categories* sets out important logical distinctions
between different kinds of attribute, but it does not enter into a
metaphysical analysis of substance itself. This takes place mainly in
*Metaphysics*, Book *Z*. In the latter, the analysis of
substances in terms of form and matter is developed, whereas these
notions have no place in *Categories*. The distinction has led
some commentators to talk of Aristotle's 'two
systems', containing two radically different conceptions of
substance (Graham 1987). In the earlier, *Categories*,
substances are simply individuals; in the later work they are
complexes of form and matter. Whether this represents a change of
view, or whether the purposes of the *Categories* simply did
not require reference to the metaphysical analysis of substance is a
moot point. It seems unlikely, however, given Aristotle's
Platonic background, that his early thought was oblivious to the role
of form in substance. Whichever interpretation of the development of
Aristotle's thought is correct, the introduction of
*substantial form* is what gives the fully developed
Aristotelian account of substance.



Aristotle analyses substance in terms of form and matter. The form is
*what kind of thing* the object is, and the matter is *what
it is made of*. The term 'matter' as used by Aristotle
is not the name for a particular kind of stuff, nor for some ultimate
constituents of bodies, such as atoms (Aristotle rejects atomism).
'Matter' is rather the name for whatever, for a given kind
of object, meets a certain role or function, namely that of being that
from which the object is constituted. Relative to the human body,
matter is flesh and blood. The matter of an axehead is the iron from
which it is made. Relative to the elements, earth, fire, air, and
water, matter is an intrinsically characterless 'prime
matter' that underlies the qualities of them all.



Aristotle acknowledges that there are three candidates for being
called substance, and that all three are substance in some sense or to
some degree. First, there is matter, second, form and third, the
composite of form and matter. Aristotle acknowledges that matter can
be a subject of predication and of change, thereby meeting one of the
main criteria set up in *Categories* (1028 b35ff). This
suggests an inadequacy or incompleteness in the account in
*Categories*, for there he had seemed to assume that being the
subject of predication belonged peculiarly to substance, and also that
a subject is an individual of an appropriate kind--what he calls
a 'this such': and matter is not an individual, but that
from which an individual is made. Two of the criteria of substancehood
presented in the Introduction above are: (v) being individuals and
kinds of individual; (vi) being stuffs and kinds of stuff. Aristotle
acknowledges that things under (vi)--'natural bodies such
as fire and water and everything of that sort' (1028
b10-11)--are, or are thought to be, substances. But,
without seeming to give much argument, he strongly favours (v) over
(vi).



The elimination of matter as a good candidate for being substance,
leaves either form alone or the composite of form and matter. The
composite seems more consonant with the doctrine of
*Categories*, for the composite is the individual. Aristotle,
however, chooses the form as more paradigmatically substance. This has
puzzled some commentators. Wiggins (1998: 232ff), for example, thinks
that the change in doctrine between *Categories* and
*Metaphysics* is wholly unhelpful. The choice of form as
substance causes perplexity because the form seems to be a universal
and equivalent to the secondary substance, and so not the most
fundamental case of substance. But whether substantial forms are
universals in Aristotle is a controversial matter. Interpreters
disagree about whether the doghood that is in Fido is best regarded as
the universal, or as the particular *instance* of the universal
doghood, other dogs exemplifying numerically different instances of
the same universal (for example, Lloyd 1981, Irwin 1988, Woods 1991,
and Bostock's commentary to Aristotle 1994). On this view, the
most perspicuous way of regarding the individual substance is not as
the composite of form and matter (though this is not wrong) but as the
form individualised in the matter. The matter is still an essential
component in the substance, but not, so to speak, as an equal partner
with the form, but as the catalyst by means of which the form becomes
an individual substance. It is clear, however, that if one holds that
Aristotle thinks that forms are universals, then forms are not
substance, for, in his attacks on Plato, Aristotle makes it plain that
universals are not substance. Substances for Aristotle are
individuals, but it is much debated whether they are individualised
forms or composites of form and matter.



There are at least three serious questions about Aristotle's
substantial forms. One we have already noticed, namely (i) whether
such forms are universals or particulars. The others are (ii) what is
the relationship between the substantial form and the properties that
enter into its definition? We have already noticed this question when
discussing *Categories*. (iii) What is the ontological status
of such forms? This is connected with the second question, for it is
connected with the question of what the substantial form is over and
above the properties essential to it. What I mean by this is as
follows. Let us agree, for purposes of argument, that *human
being* is a kind of substance and that *rationality* and
*animality* are the properties in terms of which that substance
is defined. It is uncontroversial that these properties are meant to
be objective features of the external world. But what is the relation
between the substantial form and those properties? Is the presence of
the substantial form *human being* nothing more than the
presence of those properties, or is the form something further that
is, in some sense *responsible for* the presence of those
properties? We saw in the previous section that the differentia in
terms of which a substance is defined is not treated as being
'in' objects, as other properties are. This seems to
suggest that calling an object a substance of a certain sort is not
just a way of attributing to it the properties in terms of which it is
defined. Aristotle is undoubtedly a realist about substantial forms,
in the sense of thinking them to be something more than a mere
collection of properties, but how are we to understand this
'more'?



It would be universally agreed by scholars that substantial forms are
real in the sense that they play an irreducible and ineliminable
explanatory role in the behaviour of the things in which they are the
form. There are two interpretations of what Aristotle meant by this,
one of which seems compatible with modern science and the other not.
First the compatibilist one. Empiricist philosophers of science used
to believe that the concepts in higher order sciences could be
reduced, either by means of reductive definition or by 'bridging
laws', to those in the more basic sciences (see, for example,
Nagel 1961). By such means, everything could be understood in terms of
the most basic science--presumed to be physics. Concepts in the
other sciences are thus only a kind of shorthand for laborious
descriptions in the language of physics. Few, if any, philosophers of
science believe this now. They agree that, even if the world is
'closed under physics'--every event has a complete
set of physical causes--the concepts of the other sciences are
irreducible and do autonomous explanatory jobs. Even if dogs are
wholly physical objects and even if all the atoms in dogs follow very
precise laws of physics, nevertheless when doing the biology of dogs
one will need concepts not to be found in a physics textbook. This is
not for mere shorthand convenience, but because of the kinds of things
in which, for example, the biologist or veterinary scientist is
interested. There are interpreters of Aristotle who think that this
kind of irreducibility is all that Aristotle means--or needs to
mean--by postulating an explanatory role for substantial form.
His theory is at least neutral on the question of whether there is a
closed system at the level of basic physics (Nussbaum 1978, 1984).



The stronger, incompatibilist interpretation is that Aristotle did not
believe that the behaviour of complex entities followed from the laws
that govern their parts or their matter (Gotthelf 1987, Robinson
1983). By contrast, the behaviour of the matter is influenced by what
it is the matter of. The nature of the matter places restrictions on
what the enmattered thing can do--an animal can only be made from
living tissue, not of stone or fire--but exactly how that matter
behaves depends on the substantial form present in it. The substantial
form plays, therefore, an essential role, not merely in certain kinds
of scientific explanation, but by being a fundamental efficient cause
in its own right. Whichever of these is the correct interpretation of
Aristotle, it was the second that was the core of 'Aristotelian
science' as found in scholastic philosophy, and it was this
aspect of the Aristotelian doctrine of substance that aroused most
opposition amongst seventeenth century philosophers and scientists.
They insisted that bodies behave as they do because of the mechanical
consequences of the nature of the matter from which they are made: the
matter is not 'pushed around' or organised by a
substantial form. Philosophers and scientists of the seventeenth and
eighteenth centuries believed that in rejecting such influences they
were rejecting the Aristotelian doctrine of substance.



Finally, let us consider how Aristotle fares according to the criteria
of substance with which we ended the introduction. Aristotelian
substance, whether construed as individualised form or composite of
form and matter meets (i), the criterion of ontological basicness. It
also meets (ii), relative durability, although in a rather modest
manner. Individual substances are more durable than instances of the
properties in the other categories, for it is substances that can take
on and lose those other properties. Individuals are not, however, very
long-lived and on this criterion Aristotle makes what could be
regarded as a concession to Plato, for it is form as universal, which
Aristotle does not consider properly substance, that is most durable.
There are at least two senses in which substantial forms are eternal.
First, Aristotle believes the world to be eternal and all the same
species to exist eternally. So that, even though particular objects
are subject to degeneration and decay, the species as such are
eternal. Second, generation and decay depend on the material component
in composites. Any form that does not require matter for its activity
will be eternal by nature. This applies to the active intellect, which
is an essential feature of all human intellects, and to the immaterial
movers of the cosmos described in *Metaphysics*, Book Lambda.
(Further consideration of these topics would take us into
Aristotle's philosophy of mind and his theology.)



As we have seen, substances are the paradigm subjects of predication
and change, so (iii) and (iv) are met. As Aristotle's substances
are individual things and kinds of things (v) is met. A nod is made in
the direction of stuffs and kinds of stuff, but Aristotle does not
develop this thought, so (vi) is barely met.



There are two major problems that the Aristotelian tradition has faced
in the modern period. They are: (1) explaining and justifying the
sense in which substantial forms have causal or explanatory power,
especially in light of a developed mechanistic chemistry or physics;
(2) the difficulty in understanding the relation of substantial form
to properties, especially those in terms of which a given substance is
defined. These are connected. It is because the substantial form has
genuine causal force that it is conceived of by Aristotle as a unified
entity in its own right, and not just as a name for the collocation of
properties in terms of which it is defined.



(One subject that has not been discussed is the connection between the
doctrine of substance and teleology. Aristotle regards this relation
as important, but in this entry it will have a section of its own,
 3.5
 below.)


### 2.3 Medieval accounts of substance



The standard account of the medieval treatment of the topic is that S.
Thomas Aquinas is the only important figure and what he says differs
little from Aristotle, except for making things more rigid and formal.
It is clear, however, that this is a serious oversimplification. For a
more nuanced and sophisticated view, see Lagerlund (2012), on which
this section draws extensively.



Our discussion of Aristotle ended by returning to the issue of the
unity of substantial form--what is the difference between a
collection of 'essential' properties and the form as a
unitary entity. Various aspects of this issue of the unity of
substantial form preoccupied medieval philosophers. According to
Aquinas, a substance possessed only one form, and its matter was the
essentially characterless prime matter. In other words the informed
parts of an object--in the case of a living creature, its organs,
and the various kinds of stuff that constituted it (in the end,
quantities of earth, fire, air, and water) did not possess their own
forms, but were informed by the overall substantial form. Others
disagreed. Some of the disagreements were internal to the hylomorphic
system. Duns Scotus, for example, argued that a dead person's
body was the same body as had existed when that person was alive. The
soul had departed, so the form that was the immortal soul could not be
identical with the form of the body. This argument may seem to be
specialised to the case of the human immortal soul, but, presumably, a
similar problem applies to a dead parrot: it has lost its perceptive
and vegetative souls, yet is the same body--even if it is no
longer a parrot.



This line of thought proved to be a slippery slope, and, as so often,
the downward slide was led by William of Ockham. On the one hand,
Ockham was committed to hylomorphism, in that a substance is composed
of form and matter. But he reverses the priorities of Aquinas and
Scotus by saying that the parts are actual in their own right and do
not derive their actuality from the whole: rather, the whole is
nothing but the sum of its parts. This line of thought opened the way
to atomism and to treating the unity of wholes as a matter of
convention or degree. Buridan, who represents a further development in
this direction, says



> 
> In this sense, I am not the same as I was yesterday, because something
> was part of my integrity yesterday, which has already been used up,
> and something was not part of my integrity, which has meanwhile been
> added by nourishment. (Buridan, *Physics* I,q.10, f. xiii;
> cited Lagerlund 2012: 476)
> 



It is clear that this way of thinking paves the way for atomism and
its associated problems as they emerged in early modern
philosophy.


### 2.4 Descartes, Spinoza, and Leibniz



The concept of substance figures centrally in a positive way for the
rationalist philosophers, in a way that it does not for the
empiricists. The rationalists' substances are not, however, the
individual objects of everyday life.



Descartes believed in only two kinds of substance: material body,
which is defined by extension, and mental substance, which is defined
by thought, which, in this context, is more or less equivalent to
consciousness. Descartes (like Aristotle and unlike most of his
contemporaries and immediate successors) was not an atomist. He did
not believe in a void between bodies, so there is a sense in which
there is just one material substance, numerically as well as
specifically. For Descartes, therefore, material substance falls more
naturally into the *stuff* category, rather than into the
*thing* category. The situation is different for mental
substance. The *cogito* shows that Descartes definitely
believes that each person is a different individual mental
substance.



Descartes, like the atomists, believed that matter operates in an
entirely mechanical way. There is, therefore, no causal role for
substantial form to play and, hence, no need for such forms. His two
substances are each defined in terms of one property (extension for
matter and thought for mind), hence there is no problem about the
relation between substance and the properties in terms of which it is
defined. As he does not have substances as individuals made of kinds
of stuff, there is no conflict between individuals and stuffs.



For Spinoza, there is only one substance, the existence of which is
demonstrated by a version of the ontological argument, that is thought
of as being both God and Nature. It is an unending controversy whether
Spinoza was a pantheist, or an atheist who called nature
'God' because it was the one true substance and existed
necessarily. Everything else is a mode of this one substance. The view
is analogous to a claim that the universe is space-time as a whole,
with matter as distortions in it. If this were true, material objects
would be modes of space-time. The analogy would be more exact if one
also thought of the laws of nature as equivalent to the divine
intellect immanent in nature. Spinoza's view represents the
extreme end of stressing the status of substance as the fundamental
existent conceived of as wholly necessary and self-subsistent: that
is, criteria (i) and (ii) in the original list come to take on maximum
weight. Nothing but the universe as a whole meets this criterion
fully.



Leibniz was not satisfied by this conception of divine substance, at
least in part because it confines God to what actually exists. For
Leibniz, God contains within himself all possibilities, not just the
actual world: this latter is just that maximal set of possibilities
that he has best reason to actualise. Leibniz acknowledges created
substances, though they are very intimately dependent on God. In the
*Discourse on Metaphysics* (Section 14), he says:



> 
> it is clear that created substances depend on God, who conserves them
> and indeed who produces them continuously by a kind of emanation, just
> as we produce our thoughts. (1998: 66)
> 



The analogy with thought hardly emphasises the independence of
substance! Nevertheless, created substances do constitute the created
world, and do, in that sense, meet criterion (i) for being substance.
They are also the subjects of predication, so they meet criterion
(iii). Leibniz's substances, however, are the bearers of change
(criterion (iv)) in a very different way from Aristotle's
individual substances. An Aristotelian individual possesses some
properties essentially and some accidentally. The accidental
properties of an object are ones that can be gained and lost over
time, and which it might never have possessed at all: its essential
properties are the only ones it had to possess and which it possesses
throughout its existence. The situation is different for
Leibniz's *monads*--which is the name he gives to
individual substances, created or uncreated (so God is a monad).
Whereas, for Aristotle, the properties that an object *has to*
possess and those that it possesses *throughout its existence*
coincide, they do not do so for Leibniz. That is, for Leibniz, even
the properties that an object possesses only for a part of its
existence are essential to it. Every monad bears each of its
properties as part of its nature, so if it were to have been different
in any respect, it would have been a different entity.



Furthermore, there is a sense in which all monads are exactly similar
to each other, for they all reflect the whole world. They each do so,
however, from a different perspective.



> 
> For God, so to speak, turns on all sides and considers in all ways the
> general system of phenomena which he has found it good to
> produce...And he considers all the faces of the world in all
> possible ways...the result of each view of the universe, as
> looked at from a certain position, is...a substance which
> expresses the universe in conformity with that view. (1998: 66)
> 



So each monad reflects the whole system, but with its own perspective
emphasised. If a monad is at place p at time t, it will contain all
the features of the universe at all times, but with those relating to
its own time and place most vividly, and others fading out roughly in
accordance with temporal and spatial distance. Because there is a
continuum of perspectives on reality, there is an infinite number of
these substances. Nevertheless, there is internal change in the
monads, because the respect in which its content is vivid varies with
time and with action. Indeed, the passage of time just is the change
in which of the monad's contents are most vivid.



It is not possible to investigate here Leibniz's reasons for
these apparently very strange views. Our present concern is with
whether, and in what sense, Leibniz's substances are subjects of
change. One can say that, in so far as, at all times, they reflect the
whole of reality, then they do not change. But in so far as they
reflect some parts of that reality more vividly than others, depending
on their position in space and time, they can be said to change.


### 2.5 Locke



According to Locke, we have two conceptions of substance. One is a
'*notion of pure substance in general*'
(*Essay* II xxiii 2), the other '*ideas of particular
sorts of substance*' (II xxiii 3). Both these conceptions of
substance provide difficulties of interpretation. They also both
relate to issues in contemporary philosophy of substance, in which
Locke's influence is almost as important as
Aristotle's.


#### 2.5.1 Locke on '*pure substance in general*'



Locke expresses this idea as follows:



> 
> The idea then we have, to which we give the general name substance,
> being nothing, but the supposed, but unknown support of those
> qualities, we find existing, which we imagine cannot subsist, *sine
> re substante*, without something to support them, we call that
> support *substantia*, which, according to the true import of
> the word, is in plain English, *standing under* or
> *upholding*. (II xxiii 2)
> 



The traditional rationale of Locke's doctrine of
'substance in general' is as follows. Properties--or,
in Locke's terms qualities--must belong to
something--'cannot subsist...without something to
support them'. Of course, they belong to objects, but what are
objects over and above their properties? The special category of
substantial form, as found in Aristotle, is rejected. All that seems
to be left is a bare 'something', which on pain of
regress, has no properties in its own right, except the property of
being the owner or support of other properties.



This interpretation of Locke's notion of 'substance in
general' is, however, a matter of controversy. It is contested
whether Locke actually believed in substance as a characterless
substratum. Although the first quotation above seems to affirm it,
Locke also in the same section speaks disparagingly about the idea,
comparing it to the notion that the world rests on an elephant, which
rests on a tortoise, and so on: in other words, as not constituting a
real explanation at all. Michael Ayers (1975, 1991b: 39-50)
believes that the only substratum that Locke acknowledges is the
unknown--and, Locke thinks, unknowable by us--structure of
the minute parts. This is what he elsewhere characterises as the
*real essence*. It is clear from the text that Locke is at
least uneasy with the idea of 'pure substance in general',
but it is less clear whether he feels obliged to accept an idea he
dislikes, or whether he rejects it. (For the view that he accepts it,
and why, see Bennett 1971 and 1987.)



There are indications that Locke is confused about what he means by
'substratum'. He argues that the notion of spiritual
substance is in no worse a predicament than material substance,
because



> 
> *we have as clear a notion of the substance of spirit as we have of
> body*: the one being supposed to be (without knowing what it is)
> the *substratum* to those simple ideas we have from without;
> and the other supposed (with a like ignorance of what it is) to be the
> *substratum* to those operations which we experiment in
> ourselves within. 'Tis plain then, that the idea of corporeal
> *substance* in matter, is as remote from our conceptions, and
> apprehensions, as that of spiritual *substance*, or
> *spirit*;.... (II 23 v)
> 



This argument seems to conflate the notions of *substratum* as
pure logical support with that as minute parts. If he means minute
parts, then, though it is true that we do not and, in his view, cannot
know in detail what they are, we have a theory, which he endorses,
that they are probably minute parts as conceived by the atomists,
which means they have primary qualities similar in kind though not in
scale to those possessed by macroscopic objects. This gives a
coherent, though speculative, conception of material substance. Of
spiritual substance, we have no similar hypothesis. If, on the other
hand, he means pure logical substratum, there is nothing to know, for
there is no more to it, in either the material or spiritual case, than
its role as substratum. He seems to conflate the ignorance we have of
minute parts with the logical emptiness of the idea of pure
substratum.



In fact there are three issues concerning the material underpinning of
things that Locke regards as mysterious, and he seems to move
indifferently from one to the other. First, there is organisation of
the minute parts of particular kinds of objects, which is responsible
for the manifest properties of those objects, and which he thinks will
always fall beyond our knowledge. Second is the mystery of what holds
the minute parts together: the problem of explaining attraction in a
system that only understands influence by impact (xxiii 23). Third, is
that idea of substance as a bare substratum, which is "a
supposed, I know not what, to support those ideas we call
accidents" (xxiii 15).



Perhaps it is more profitable to ask whether, in his own terms, Locke
*ought* to have accepted bare substratum. If we accept that the
question of what binds together the qualities of a macroscopic object
can be answered by appeal to the minute parts, the issue would then be
what binds the primary qualities of atoms. Do the size, shape, mass,
solidity of a particular atom require a bare substratum to inhere in
for them to constitute a coherent object? Would they, without such a
substratum be just a stack of qualities, a house of cards with nothing
holding them together? There does not seem to be anywhere in the text
where Locke discusses this problem--that is, the coherence of
atoms as opposed to composite objects--explicitly. One possible
resort is to treat solidity as the core or master quality and all the
others as features of it. One would never ask what binds together a
patch of colour and its shape, because the shape is the shape
*of* the colour patch, and, though the shape of something can
change, its shape cannot come away from it, like a separable
component. Perhaps the shape, size and density of an atom are
similarly features of the solidity. The quality solidity would then
become equivalent to the notion of material stuff or material
substance and Locke shows no sign of wanting to elide the ideas of
quality and substance in this way, though it should be noted that this
is what Descartes does with extension. Because he does not believe in
void, extension carries with it the other basic properties of matter
as features of it.


#### 2.5.2 Locke on '*ideas of particular sorts of substance*'



The ideas of particular sorts of substance--called
*sortals*--are formed



> 
> by collecting such combinations of simple ideas, as are by experience
> and observation of men's senses, taken notice of to exist
> together, and are therefore supposed to flow from the particular
> internal constitution, or unknown essence of that substance. Thus we
> come to have the ideas of a man, horse, gold, water,
> *etc*... (II xxiii 3)
> 



Thus, for Locke, the real essence is an unknown atomic constitution.
The types that we categorise them in depend on the properties we
happen to be able to perceive and kinds or sorts are defined in terms
of these observable properties. Definition in these terms he calls
'nominal essence'. Our concepts of natural substances
presuppose that the nominal essence hides a real essence--that
is, that all water, gold, horses etc are in some way similar at a
microscopic level. But he both denies that these real essences play
any role in the formation of our concepts and is deeply sceptical of
our ever being able to discover what they are. His attitude towards
the Aristotelian view is expressed later in the paragraph just
quoted:



> 
> ...a philosopher...whatever substantial forms he may talk
> of, has no other idea of those substances than what is framed by a
> collection of those simple ideas which are found in them....
> 



Locke's doctrine of sortals is in some respects realist and in
some conceptualist or conventionalist. It is realist in at least the
following ways.


1. The properties [ideas] in terms of which sortals are defined do
correspond to real qualities and powers in the world. There is no
sense in which these building blocks of reality are creatures of our
conceptual scheme.
2. The properties invoked by nominal essences are "supposed to
flow from the particular internal constitution, or unknown essence of
that substance"(xxiii 3). This internal constitution
"makes the whole subsist by itself" (xxiii 6).



Thus Locke is entirely realist about individual bodies and their
properties. He is more conventionalist, however, about their
classification under particular sortals. There are four ways in which
he is a conceptualist about particular substances, as we classify
them.


1. There is nothing over and above the properties of an object
corresponding to our substance concepts--nothing, that is, like a
substantial form--present in the world. Sortals are entirely
formed by our minds, in the light of the properties perceived to be in
the world.
2. The boundaries we draw between kinds of things are, to some degree
at least, arbitrary and concept relative.


> 
> I do not deny, but nature, in the constant production of particular
> beings, makes them... very much alike and of kin one to another:
> but I think it nevertheless true, that *the boundaries of the
> species, whereby men sort them, are made by men*.... (III vi
> 37: italics in original)
>
3. The situation in (ii) is greatly aggravated by our ignorance of
real essences. If we could know those more accurately, we would know
better where to draw the boundaries.
4. The disposition of properties in nature need not have been as it
is and might actually contain oddities not corresponding to any of our
sortals. Sortals, unlike Aristotelian species, place no constraints on
how individual objects must or ought to be.



Locke's contribution is, therefore, three-fold. He brings to
centre stage the question of whether properties require some
substratum or bare particular to inhere in or belong to. He asserts
that the substantial nature of the physical world is the unknown
structure of atomic parts, not a substantial form which reflects our
usual concepts. Third, he develops a theory of substance which is
realist about particular objects and their properties, but
conceptualist or conventionalist about our classifications, within the
constraints that the facts about particulars and properties
impose.



There is one important context, however, where Locke does not appear
to talk in a conventionalist way about sortal identity, but in a way
that seems to be reminiscent of substantial forms. This is when he is
discussing the individuation of living things. He understands ordinary
bodies as mereological sums of atoms. As such, any change of particle
constitutes a new object, for a mereological sum is individuated by
its parts and a change of parts means a change of the object
constituted by those parts. Treating ordinary, non-living, bodies as
complex enduring objects is a matter of convention determined by the
concepts we happen to possess. Living things, however, have a deeper
principle of unity.



> 
> That being then one plant which has such an organization of parts in
> one coherent body, partaking of one common life, it continues to be
> the same plant as long as it partakes of the same life, though that
> life be communicated to new particles of matter vitally united to the
> living plant.... (*Essay* II.27.4)
> 



One might wonder what this 'common life' is supposed to
be, especially in the light of his rejection of Aristotelian
'substantial forms'. Furthermore, it is tempting to argue
that all coherent, solid bodies--such as a lump of rock or
plasticene--have some principle of organisation that persists
through change. Living objects are simply the most dramatic case of
this. (Though Peter van Inwagen (1990) defends the view that only
living things and atoms are real entities: inanimate complex bodies
are not true individuals.) Nevertheless, though the appeal to
'life' seems to modify Locke's conventionalism, it
still leaves open the possibility that the divisions we make between
different species are conventions, because, though we can recognise
life (or a 'continuing principle of organisation') itself,
it is still relatively arbitrary and concept-dependent where life (or
'principle of organisation') of one kind ends and another
starts. So our division of things into species, though grounded in
real continuities in the way that our non-biological (or non-natural)
concepts are not, is still nominal.



As we shall see, the idea that there is a real unity that is passed on
through the life of an object or through any principle of organisation
is something that Hume criticises and rejects.



The potential for a stronger realism in Locke has been exploited by
Putnam and Kripke in their development of a modern, essentialist
conception of natural kind terms. Locke was pessimistic in two
connected respects. First he was sceptical about the possibility of
science discovering the nature of the real essences--the
structures of atoms or molecules--that underlie kinds of
substance picked out by our ordinary sortals. Second, he doubted
whether the objects picked out by our actual substance concepts really
shared a real essence in the way we assume that they do. He was not
confident, that is, that everything we call gold, or iron, or a
monkey, was actually interestingly similar at a non-superficial level.
Both these forms of pessimism proved largely unfounded. The
consequence of this is the possibility of bringing together real
essence and the sortal concepts originally picked out by a nominal
essence. We now know water to be H2O and iron to be the
element of atomic weight 56. Our substance concepts were, often at
least, tracking real essences in the world. This involves
reinterpreting the rationale of our substance concepts. Locke thought
that our concept of gold was properly expressed as 'anything
gold in colour, malleable, soluble in aqua regia'. He thought
that we add the optimistic assumption that there will be similarity at
the microscopic level. What many philosophers, under Putnam's
influence, now think he should have said is that gold is *that kind
of thing which is individuated by a particular kind of minute
structure that underlies* the stuff that is gold in colour,
malleable, soluble in aqua regia. In other words, our confidence that
these kinds have a genuine real essence is built into the concept. If
this is correct, then our ordinary 'natural kind'
concepts, like *water* and *gold*, have built into them
intimations of a deeper unity than that supplied by superficial
features, even if it be allied to a complete agnosticism about what
that unity might consist in or whether we might ever uncover it.



How does Locke, then, rate against the six criteria for substancehood
that were set up in the introduction? Accepting, for these purposes,
that Locke believed in substratum, we can apply these tests both to
substratum, and to his 'ideas of particular sorts of
substance'.



First, consider substratum. (i) Ontological basicness. There is a
sense in which it is ontologically basic, but it is a rather empty
sense: it is the *substancehood* of everything, without
explaining the nature of anything. (ii) Durability. Again, it meets
the criterion, but in an empty way. It is difficult to see how it
could be destroyed (like Aristotle's prime matter) but it has no
positive nature. (iii) and (iv) Bearer of predication and subject of
change. As with matter for Aristotle, it meets the first of these
standards well, but, in so far as it is a component only in atoms, it
is not the subject of change. (v) and (vi) Kinds of individuals and
stuffs. Although in everything, it is itself no kind of thing and
therefore no kind of individual or stuff. Substratum's claim to
substancehood does not rest, however, on meeting the tests itself, but
on being what enables particular kinds of substances to *be*
substances. According to the believer in substratum, it is in virtue
of their inhering in a substratum that a collection of properties can
constitute an enduring, change-sustaining thing of a certain kind.
Without that support, individual instances of properties could, if
they could exist at all, be no more than ephemeral events.



We have seen that Locke's particular substances are
*kinds* of things, and because they are kinds they correspond
to Aristotle's *secondary substances*. But we have also
seen that the boundaries between these kinds are largely a matter of
convention, which is not true of Aristotle's secondary
substances. In so far as their individuation is dependent on human
convention, they are not ultimately real in their own right. But
though they are not real as kinds, the individual parcels of matter
that we classify in these ways are perfectly real. Locke does not, as
far as I can see, refer to these individuals as
'substances'. Substances, considered as kinds, or
instances of kinds, can sustain change--living things, for
example, change in size throughout their lives. Most individual
parcels of matter, however, become different individuals if they
change any of their parts; although we have seen that this does not
apply to living things, where there seems to be a metaphysical
component called sameness of *life*.



In general, Locke's particular substances are not ontologically
basic, because their essences are nominal, though this is not so
clearly true for sortals naming biological kinds. Locke's
conceptualism about such substances makes most of the tests
irrelevant, which are cast within a realist framework. Locke's
'particular substances' are kinds that are individuated
conventionally, and so are not real substantial kinds, by Aristotelian
standards. But Locke is not without substance other than substratum,
for his real essence--that is, the atoms and their
structures--are his real substances, and what we say above about
the substantiality of atoms also goes for Locke.


### 2.6 Hume and Kant on substance



It is plausible to maintain the general thesis that there are many
issues on which Hume was a sceptic or nihilist, but where his legacy
is more reductionist than sceptical or nihilist. This general thesis
can be explained and illustrated by considering his treatment of
substance, for it is a case in question.



According to Hume, in the *Treatise*, our belief in substance
is the result of a mistake or illusion.



> 
> When we gradually follow an object in its successive changes, the
> smooth progress of the thought makes us ascribe an identity to the
> succession...When we compare its situation after a considerable
> change the progress of the thought is broken; and consequently we are
> presented with the idea of diversity: In order to reconcile which
> contradictions, the imagination is apt to feign something unknown and
> invisible, which it supposes to continue the same under all these
> variations; and this unintelligible something it calls a
> *substance, or original and first matter*. (1978: 220)
> 



Hume's target is any account that postulates a unifying
'something' that underlies change, whether this be a
characterless substratum, a substantial form or (though this is not
explicitly mentioned) something like the 'continuing life'
that Locke sees as passed on in living things. The crucial point is
that a succession of very similar things does not constitute the real
continuation of anything, only the illusion of real continuation.



Thus Hume's treatment of substance is like his treatment of
causation, in that he sees both as the projection onto the world of a
tendency of our minds either to pass from one thing to another or to
associate them in some way. He either doubts that there are such
things as substance or causation (scepticism) or even positively
denies that there are (nihilism). Out of Hume's very forthright
negative attitude there developed two more subtle variants. One of
these variants is in the empiricist tradition. That tradition modified
Hume's approach by developing it into a form of reductionism.
The experiences that gave rise, through habit, to the mistaken belief
(in, for example, substance or causation) are presented as what the
belief really affirms. That is, the empirical basis for what Hume
deems to be an illusion, is reinterpreted as the reductive account of
the concept. Causation then becomes constant conjunction, or substance
a name for a bundle of properties organised in a certain way or the
continuing of the possibility of certain sensations.



Kant developed the other variant. He took Hume's
'tendencies of the mind to pass' from one idea to another,
without which we could not construct the world, and canonised them as
a priori categories of the understanding. Hume's empiricist
emphasis is psychological. It concerns what we are habituated to do.
Because of his empiricism, he will not bring non-psychological
necessity into it. Nevertheless, there is the implication that making
these transitions is the only way in which one *can* understand
the world. Kant drops the empirical psychology and makes it a matter
of a priori psychology, that only by employing certain categories
could we have experience as of a physical world. It is only by
understanding the world as possessing enduring spatio-temporal
objects, which enter into causal relations with each other (that is,
it is only by applying the categories of substance and causation) that
we can have intelligible experience. Substances--that is, a
framework of stable, enduring objects--are essential, but the
source of this necessity lies not in how the world is in itself, but
in the framework that we are obliged to impose.



In the Kantian philosophy of P. F. Strawson (1959, 1966), this
framework of necessity is taken in a more common-sense and realist
spirit. The world must possess such enduring objects for it to be
intelligible for us--indeed, for us to be part of it, for we are
essentially stable bodies amongst other stable bodies. The important
point for both Strawson and Kant is that there must be substances for
there to be a coherent empirical, spatio-temporal world.
*Substance* has become a formal concept of central
importance--that is a concept with a special central role in the
structure of our conceptual scheme--rather than being the name
for certain kinds of important things in the world. This distinction,
however, is one that has to be handled carefully, especially within a
realist Kantian framework, such as Strawson provides. This should
become clear below when we discuss Wiggins's theory, which is
both Aristotelian and Strawsonian. Nevertheless, it gives ground for
adding the seventh of the marks of substance mentioned in the
Introduction, namely that substances are those enduring particulars
that give unity to our spatio-temporal framework and individuation and
re-identification of which enables us to locate ourselves in that
framework.


## 3. Contemporary Controversies



Two major areas of controversy require attention. First, there are the
issues concerning how to characterise substance in contradistinction
to properties and the other categories. There are at least two major
questions here. One concerns defining the notion of substance. In
particular, there has been much debate about whether substance can be
accounted for in terms of its special kind of *independence*.
The other is whether substancehood requires some extra component
beyond properties, (and, if so, what?) or whether a 'bundle of
properties' theory of substance is adequate. Second there is the
relation between substances and our practices of individuation and
reidentification. In particular, we shall look at the issue of whether
objects must be individuated under the kind of sortal expressions that
correspond to Aristotelian substance concepts, or whether a more
generic notion, such as *physical body*, will suffice. This
latter concern will lead on to a consideration of the connection
between substance and teleology.


### 3.1. How substances are distinguished from things in other categories



One natural response to the question of what distinguishes substances
from properties is that properties depend for their existence on
substances, for they are properties *of objects* (that is, of
individual substances), but that substances do not similarly depend on
properties for their existence. The point cannot be made quite so
simply, however. Properties could not exist without objects to be
properties of, but neither could substances exist without properties,
so the dependence appears to be mutual.



This problem can be overcome by more careful expression of the point,
making it clear that we are not talking about properties in general
and substances in general, but about particular instances or cases of
a property and the particular objects to which they belong. A
particular property instance cannot exist and could not have existed
without the substance of which it is a property, but the particular
substance can exist and could have existed without that property
instance. Thus, a particular instance of colour cannot exist, and
could not have existed, without the object of which it is the colour,
but the object can exist without the colour instance, for it may
change colour and remain the same object, or it could have had a
different colour from the start.



Various problems can be raised for this account. The most obvious is
that it does not, as stated, distinguish between substances and
events. Some property-instances belong to events rather than
substances. The performance of a symphony, for example, is an event,
and it may possess the property, in one of its movements, of being
allegro. It seems plausible that this particular case of
something's being allegro could not have been exemplified by
another performance, but the performance might go on to be andante in
another movement, so the event can continue to exist without that
original property. The assimilation of events with substances in this
way seems strained, however. It does not seem natural to say that the
same event was first allegro, then andante, because it is more natural
to attribute the different properties to different parts of the event,
which are themselves events (in this case, *movements*). This
brings out a major difference between substances and events, namely
that the temporal parts of events are themselves events in their own
right, but the temporal parts of objects--meaning by that
expression the temporal phases of an object's
existence--are not themselves objects. Indeed, it is not natural
to talk of the temporal parts of objects, though some philosophers
(led by David Lewis (1986), but see also Sider (2001), Hawley (2001)
and the entry on
 temporal parts)
 think that there are compelling philosophical reasons for doing so.
The rationale implicit in our ordinary concept is that an object is
wholly present at all the temporal points of its existence. I say
'implicit rationale', because it seems no more natural to
speak of an object as being 'wholly present at all temporal
points of its existence' than it is to say that it has objects
as its temporal parts. Nevertheless, one does not think of a
long-lived object as consisting of a series of short-lived objects
stacked end to end, but one does think it natural to think of a
drawn-out event as consisting of a series of shorter events. If it is
not natural to think of objects as having objects as their temporal
parts, this seems to commit one to thinking of objects as wholly
present at all times of their existence, strange though this form of
expression may also be.



The difference between substances, events and properties can now be
expressed as follows. Substances and events are distinguished from
properties by the fact that properties are the kinds of things the
instances of which depend for their existence on the particular
substance or event by which they are instantiated, whereas substances
and events are such as not to depend for their existence on particular
instances of properties. And substances are distinguished from events
in the following way: events are those property-instantiators that,
when they exist through time, are temporally composed of further
things of the same category (i.e., events): substances are those
property-instantiators that, when they exist through time, are not
temporally composed of things of the same category (i.e., of
substances) but endure singly through the period.



Lowe, in his (1998), which contains a very thorough discussion of all
the topics discussed in this section, defends an
'independence' account of substance, which he states in
terms of *identity*, as follows:



> 
> *x* is a substance if and only if *x* is a particular
> and there is no particular *y* such that *y* is not
> identical to *x* and the identity of *x* depends on the
> identity of *y*.
> 



He considers two objections to his own account which would seem to
apply to all *independence* accounts. One is that it cannot
cope with essential properties, for it seems to imply that, for any
given property-instance, a substance can exist without it, which is
not true of essential properties. The other is that it cannot cope
with the necessity of origin for individual identity.



Lowe responds to the former objection by saying that essential
properties are identical with the substance, so cannot be cited as
something other than substance that meets his criterion for being
substance. It is not clear that this will work. The idea that the
*essence* is identical with the substance is Aristotelian, but
it is not clear how this applies to essential properties, taken
individually. We have already seen, in our discussion of Aristotle,
that the relation between the essence as some kind of unity and the
properties that seem to constitute it is not clear. He copes with the
second by denying that origin is essential to identity. Unfortunately,
he argues for this position by citing human subjects: Socrates, for
example, would still have been who he was even if he had had different
parents. This is, of course, controversial about humans, but it is our
Cartesian intuitions that make it plausible in that case. That this
table, for example, could have been the same object even if made from
different material does not have the same plausibility. 



Whether these objections to the above versions of the
*independence* account can be answered is unclear. Hoffman and
Rosenkrantz (1994 and 1997) develop a different, though probably not
incompatible, conception of the relative independence of substances
compared to other categories. Substance, they say, is the only
category of thing that might have only one instance through at least a
minimally extended period of time. Thus, for example, there is no
possible world that has, in a given period of time, only one event,
for any non-instantaneous event will be made of events that are its
parts. Similarly for properties or tropes, there can never be only one
because any one entails the existence of others, as, for example, the
existence of a red property (instance) entails the existence of (an
instance of) the property colour. By contrast, there could exist
through a period of time just one substance, provided that it was
atomic.



As Mackie (2000) points out, the full statement of this theory
involves various relatively ad hoc restrictions. More importantly, it
does not seem to explain what unifies the category of substance, for
it does not say that it is true of any substance that it could
conceivably be the only substance existing for a period of
time--indeed, it could not apply to non-atomic substances, for
complex ones can exist only if other substances--those that
constitute their parts--also exist. It implies only that
*something* from the category of substance might so exist and
that this could not be true of any other category. One might wonder
what enabled substances that could not exist alone to count as
substances at all.



If either of the above accounts are successful, substances, properties
and events are distinguished. The question remains, however, how far
these are nominal and how far real distinctions. That there is a
difference between substance concepts and property concepts has
definitely been shown, but does it follow that there are, in reality
two different kinds of *thing*, namely properties and
substances? The answer might seem to be obvious. Given that there are
substance concepts, if those concepts are instantiated, then there are
substances in reality. *Cat*, *table*, *human
being*, are substance concepts by the above accounts, and there
are cats, tables and humans, so there are substances in reality as
well as properties.



The matter is not so simple, however. It is possible, and not
uncommon, for concepts of a certain kind to be exemplified, but for it
to be the case that, nevertheless, entities answering directly to
those concepts are not included in the most economical statement of
one's ontology. This is reductionism, and it can operate in
either of two ways, namely either analytical reductionism or what one
might call de facto or 'nothing but' reductionism. In the
present case, it would conform to the analytical option if the concept
of substance could be analysed in terms of properties or events (e.g.,
'to be a substance =df to be a collection of properties bound
together in way W'). But one might still hold that, though the
concept of substance is not precisely analysable and is indispensable,
substances in fact are *nothing but* collections of properties.
This latter is the de facto option. So the existence of substances
does not show that the concept is important from a philosophical
perspective, or, if it has some significance, whether this is just as
a necessary part of our conceptual scheme, or as an ineliminable
feature of reality itself.


### 3.2 Bundle theories versus substratum and '*thin particulars*'


#### 3.2.1 Bundle theories and their problems



We have just noted that there could be analytically reductionist or de
facto reductionist accounts of substance in terms of properties. It is
also the case that the properties might be conceived of as universals,
or as individuals--that is, property-instances, which are
sometimes called 'tropes'. There are, therefore, four
options for the bundle theorist.


1. The concept of substance can be analysed in terms of some relation
between properties conceived of as universals.
2. The concept of substance can be analysed in terms of properties
conceived of as individuals, e.g., as property-instances or
tropes.
3. Substances are in fact no more than bundles of properties
conceived of as universals.
4. Substances are in fact no more than bundles of properties
conceived of as individuals.



The main objections to the 'universals' form of the theory
rest on its apparent commitment to the Identity of Indiscernibles, for
if an object is no more than a bundle of properties, then if
*a* and *b* have exactly the same properties, they are
the same bundle. Whether it does carry this commitment may depend on
whether one allows spatial points as particulars, in addition to the
properties that are universal. If one did, then the universal theories
would not entail the identity of indiscernibles, for the same
universals could be in two bundles by being at two different
locations.



If properties are conceived of as individuals--otherwise known as
tropes, property-instances or individualised forms--then there
cannot be a problem about the distinctness of exactly similar bundles,
for the difference is built into the identity of the elements of the
bundle, as it is not if the bundle is made of universals. The problem
for this version of the bundle theory seems to be that it is difficult
to individuate or distinguish tropes in a way that makes them suitable
to be individuals--in one sense, the substances--from which
objects are made (Armstrong 1989: 115ff). For example, if an object
has a size, a mass, and a motion, are the size and the mass different
tropes and is it not strange to think of the size alone as a genuine
particular suited to be treated as an 'atomic' component
of the whole? One way out of this problem may be to resort to the
notion of a master property that was invoked in the discussion of
Locke on substratum
 (section 2.5.1);
 that is, to the notion of one property of which all the others are
modes, as visual shape is a mode of colour, or extension is the master
property of matter for Descartes. In the Newtonian model, solidity
might fill this role, for shape is merely the outline of the solidity
which constitutes the heart of the object. In a sense, theories of
this kind are not ordinary bundle theories, for one property is chosen
to fill the role of substratum, because the other properties inhere
in, or are modes of, it. Whether anything could perform this role from
amongst the properties that are basic to modern, post-Newtonian
physics--properties such as charm, energy, spin and mass--is
not easy to judge.



One objection often made against the theory is that bundles are
mereological sums, rather like Locke's 'masses of
matter', and that, therefore, any change of property is a change
in the identity of the object. Various forms of essentialist solutions
to this problem have been suggested, for example, by Simons (1994),
and Barker and Jago (2018). I must admit to having difficulties seeing
why the view that objects are constituted solely out of
property-instances should commit one to a mereological view, any more
than the theory that they are constituted solely from material
particles would, so I do not see this as a special problem for the
bundle theory.


#### 3.2.2. The concept of substratum or 'thin particular'



If one is not satisfied with a bundle theory of substance, so that one
thinks that an individual substance is more than a collection of
properties, how is one to understand this 'more'? This
question can be given a deflationary or a substantive answer. The
deflationary answer is that a substance is a *thing which has*
properties, and that is all one needs to say (see, for example, Crane
and Farkas 2004, 143f, and Chisholm 1969). An object is not composed
of properties and some further ingredient--the
'thingy' bit--an object is something that simply has
properties. Any feature of it can, of course, be regarded as a
property, but that does not render an object nothing but a collection
of properties. There seems to be a clash of intuitions at this point
about what makes sense. An opponent of the deflationary view will say
that properties, however understood, must be components of objects,
conceptually or formally speaking. If they are not the only components
in this sense, one must say something about the nature of the rest.
The deflationist thinks that this line of thought embodies some kind
of category mistake in the way it handles the idea of a component. The
anti-deflationist will argue that the fact that we are talking about
components only in a conceptual sense does not alter the fact that we
are obliged, once we start, to offer an account that is complete and
distinguishes the various elements.



Bennett offers one way out of the need to postulate a mysterious
substratum:



> 
> When I say 'This is an orange' I mean that there are here
> instances of certain properties such as orangeness, sphericality etc.,
> and I indicate that I am *operating on my ideas of those instances
> in a certain combining manner*. (1987: 202; italics added)
> 



This solution, as Bennett recognises, makes substancehood a function
of how we operate on the properties we perceive. It is, in that sense,
more Kantian than realist. As what it recognises as out there in the
world is just a bundle of properties, it does not dissolve the problem
in the way that a deflationist would require.



Substantive theories take the thought of a further component
seriously, and, though they do not seem to be generally distinguished,
there are two main conceptions of this extra element, which I will
call the 'thin particular' and the
'substratum' conceptions. 'Thin particular' is
an expression of D. M. Armstrong's. It is the particular in
abstraction from its properties. When considered with its properties
it is a *thick particular*. The important point is that thin
particulars really are particulars. 'Bertrand Russell might have
been a fried egg': that is, the thin particular associated with
one set of properties and, hence, with one thing, might have belonged
to another. Different properties might have been hung on this hook. It
is not so clear, by contrast, that a substratum of the kind Locke
considers, or like Aristotle's prime matter, is a particular in
this sense. It is more like a kind of stuff--the substantiveness
on to which properties are stuck. On this conception, the suggestion
that the 'piece' of substratum or 'prime
matter' that is *here* in object *a*, might always
instead have been *there* in object *b*, seems to lack
content.



It is useful at this point to take note of the three different
functions the thin particular or substratum might fulfil. Its role
might be (i) to bind the properties into a unity, so that they do not
'fall apart': (ii) to individualise them, if they are
universals: (iii) to carry one across the categorial barrier from
property to substance; that is, to be what it is that makes something
to be in the category of substance.



The first role will not be necessary if one thinks that there is a
'master property' of which the others are modes, or if one
thinks that unity can come from some causal or organisational
connection. (ii) will not apply to a tropist theory, or if one thinks
that location will do the job. (iii) rests on the intuition that no
collection of *properties* could, in themselves, amount to a
*substance*: the very idea is a category mistake, and only the
presence of a special 'substantializing' element could do
that. It might be argued that this intuition begs the question against
the bundle theory. At the current state of the debate, it looks as if
there is no compelling reason for accepting substratum.


### 3.3 Substances and sortals



The Aristotelian tradition anchors the concept of substance, at least
in nature, primarily to instances of species of natural object. The
Kantian tradition ties it to those enduring bodies the individuation
of which gives sense and structure to our spatio-temporal framework.
David Wiggins (1967, 1980, 2001) has made a sustained attempt to prove
that these two objectives necessarily go together and to make the
Aristotelian notion of substance, even including its bias towards the
biological, central to our practice of individuating objects.



Wiggins assumes that individuating a temporally enduring object
involves being able to re-identify it at different times and under
different descriptions. This assumption makes it possible to state
substance individuation using the language of identity. Within the
scope of this assumption, he makes two claims. The first is the sortal
relativity of identity: that is, when any *a* and *b*
are asserted to be the same thing, they must be the same
*something-or-other*, and the *something-or-other* must
be the kind of concept that answers 'what is it?'
questions. In other words, there is no such a thing as 'bare
identity'--identity under no concept at all. Furthermore,
the relevant concept must be an Aristotelian substance concept or
sortal. More formally, this can be expressed as follows:



> 
> If *a* = *b* then (a) there is a sortal *F* such
> that:
> 
> 1. *a* is an *F*
> 2. *b* is an *F*
> 3. *a* is the same *F* as *b*.
> 
> 
> 



The second claim is that is that if the object picked out by
'*a*' also falls under another sortal, *G*,
then so will the object picked out by '*b*', and it
will be the same *G* as *a*. This is represented as an
application of Leibniz's Law, for if *a* is
the-same-*G*-as-*a* (as it must be) then, as *a*
= *b*, *b* must be
the-same-*G*-as-*a*.



> 
> (b) for any sortal *G*,
> 
> 1. *a* is *G* iff *b* is *G*,
> 2. if *a* is *G* then *b* is the same *G*
> as *a*.
> 
> 
> 



The conclusion is striking because it is a denial that *a* and
*b* might be identical under one form of identification, but
not under another. In fact it implies that every individuable object
falls under just one ultimate sortal. (Wiggins admits this in 2001: 67
n.7. What is meant by *ultimate* sortal will emerge below.) For
every ultimate sortal has its own principle of individuation, and if
an object fell under more than one, there could be a time at which it
satisfied the criteria for one and not for the other. Wiggins's
thesis is a very strong claim, apparently backed up by a powerful
argument. It is a strong claim for it purports to prove that any world
with individuable objects must be constituted by Aristotelian
substances. The argument is powerful because it follows by simple
logic, granted seemingly plausible claims about identity, and
Leibniz's Law.



On the other hand, there seem to be many cases of objects, which can
be identified under a variety of concepts, leading to different life
histories. This is termed *relativity of identity*. For
example, *a* and *b* may be the same person but not the
same child because *b* is a grown up and no longer a child. Or
*a* and *b* may be the same lump of clay but not the
same statue because *b* is the lump after it has been reshaped
out of its statue shape. These are the most typical kinds of counter
examples and Wiggins has responses to both. He deals with the first by
invoking the concept of a *phase sortal*. A phase sortal is one
that, by its meaning, denotes part of the life history of something,
which, as a whole, is denoted by another sortal. So *child* is
a phase sortal that applies to a phase of the things fully designated
by *human being*. This illuminates an important aspect of the
concept of a sortal. It is a necessary condition for
*F*'s being an ultimate sortal that, whenever it applies
to something, it applies in a present-tensed manner to the thing
through the whole of its existence.



The statue and the lump of clay are dealt with by denying that the
lump and the statue are identical: the lump of clay
*constitutes* the statue, but is not identical with it. Notice
that he could have argued that the statue was just a phase of the
lump, but he does not do so because *statue* is not, by its
very meaning, a phase sortal: *statue*, unlike *child*,
does not indicate by its meaning a period in the existence of
something.



So Wiggins deals with objections mainly by two distinctions. One is
between sortals that apply to objects through the whole of their
existence, and sortals appropriate only to a phase of their existence:
the other is between the 'is' of identity and the
'is' of constitution. Correspondingly, criticism centres
on whether the concepts under which we pick things out behave in as
regimented a way as Wiggins requires, and on whether the
'is' of constitution is sufficiently different from the
'is' of identity to perform the task he wants of it.


#### 3.3.1 The discipline of sortal identification



There are certain kinds of counter-example that Wiggins does not
discuss in print. There might, for example, be a sword-stick, which
has its blade removed and the inside of the cane filled with resin, so
that it ceases to be a sword but remains the same walking stick.
*Walking stick* and *sword* are perfectly good concepts
for picking out objects, if any artefactual terms are, and, on pain of
excessive artificiality, a sword-stick is both a sword and a walking
stick. This kind of example does not appear to occur amongst natural
objects, but, as a sword-stick is a perfectly good reidentifiable
object, this fact about natural objects would seem to be a contingent
truth about them. Of course, it is not an *accident* that
nature works that way, but neither is it a conceptual requirement.
Wiggins's original proof was a priori, and it should allow no
exceptions. Wiggins's response to this example (in personal
communication) is that the sword-stick ceases to exist when it loses
its ability to function as a sword and is replaced by a walking stick.
But this response too is *ad hoc*. It embodies the principle
that if anything is both an *F* and a *G*, where
*F* and *G* are normally ordinary sortals, then it is
really an *F*/*G* and ceases to exist if it loses either
its *F* or its *G* features and is replaced by something
that is either just an *F* or just a *G*.



One possible way out of this kind of case is to say that the sword is
a phase of the walking stick, thereby introducing ad hoc phase
sortals. By the expression 'ad hoc phase sortal' I mean a
sortal that can be used sometimes as a phase sortal, designating an
object only through part of its existence, and sometimes as an
ultimate sortal, designating an object through the whole of its
existence. Of course, even a normal phase sortal might, contingently,
in a given instance, designate an object through the whole of its
existence. One might say that the phase sortal *baby* could
designate something through the whole of its existence if, for
example, a human being died at the age of six months and hence never
got beyond babyhood. But it remains the case that, by dint of the
meaning of the term, a baby is a phase of a human being (or, perhaps,
some other animal) even when a particular creature fails to get beyond
that phase. A sword is not, however, in virtue of the meaning of the
word 'sword', a phase of anything, and to use the term to
name a phase of something in a given case, when it suits, is ad hoc.
Allowing sortals of this kind would put the concept of sortal under
pressure, for an ultimate sortal was originally thought to be a kind
of concept that necessarily characterises an object present-tensedly
throughout its existence, not a concept that sometimes does and
sometimes does not. If it were possible for a given sortal, such as
*sword*, sometimes to be an ultimate sortal and sometimes a
phase sortal, it is not clear how such an expression would differ from
an expression such as *brown thing*, which may or may not
characterise something through the whole of its existence. But it is
vital that the distinction between sortals, phase or ultimate, and
expressions such as *brown thing* be clearly maintained, if the
notion of sortal is to serve any formal purpose.



More importantly, that there are no ad hoc sortals is essential to the
significance of the formal proof that there is no such thing as
relative identity. In logic and in the application of Leibniz's
Law, '*a* is *F*' is normally equivalent to
'*a* was, is or will be *F*', otherwise the
Law would not apply to such accidental properties as 'is
brown'. This is also the way phase sortals work: a human being
is, was, or will be a baby. The argument against relative identity
works by arguing that, if one allowed relative identity, a
contradiction would follow, namely that one would get a situation in
which *a* is *G*, *a* = *b* and *b*
is not *G*. For this to be a contradiction, 'is
*G*' must be univocal in both cases as either
'--was, is or will be *G*' or '--is
at all times *G*'. For there is no inconsistency in
*a* is, was, or will be *G*, *a* = *b*,
and *b* is not at all times *G*. But if, whenever a
contradiction is generated, one deems one of the sortals to be a phase
sortal, and so to fall under the 'is, was, or will be'
rubric, and the other to be the ultimate sortal which applies at all
times, no contradiction will ever arise. All the cases of putative
relative identity could be reconciled with Leibniz's Law by
deeming one of the sortals to be operating as a phase sortal in this
instance.



Another possible line is that a sword-stick is not one object, but two
objects that share some of their matter. This introduces a category of
what one might call *Siamese objects*. It can be argued,
however, that allowing this kind of entity undermines Wiggins's
opposition to those, like Ayers, who think that the concept for
reidentifying objects is, or often is, something more generic than
sortal concepts; something akin to *material body*. To see how
this may come about, we must consider the rationale for Ayers's
theory.



The fact that sortals do not seem to follow the discipline that
Wiggins wishes for them might be taken to support the view that
substances can be individuated under much more generic notions, such
as *same body* or *same material thing* (Ayers 1991a).
On this view, material cohesion is what picks out paradigmatic
physical things. Wiggins regards these ideas as too generic to be
adequate on their own. Such a concept cannot be "understood
except as determinable that has *dog*, *horse*,
*ball*, [etc] among its determinations" (1997:
417-8).



Ayers, on the other hand, thinks that Wiggins takes the notion of body
too loosely, because he [Wiggins] classifies as 'lump-mass
terms' everything from bars of soap and pats of butter to pools
of water and pots of stew (Ayers 1991b: 229-30). Wiggins, in
other words, does not take seriously enough the cohesiveness of real
bodies, conflating them too easily with looser masses of matter. One
natural thought is that we can reidentify middle-sized physical bodies
that have fairly stable properties, irrespective of whether there is
any interesting sortal term under which they fall. This is not to say
that they could be reidentified under the purely generic notions
*body* or *physical thing*, if there were no continuity
of manifest properties.



That this may be a powerful criticism of Wiggins's view can be
seen by considering the notion of a Siamese object, which seemed to be
necessary to answer the kind of problem posed by the sword-stick. The
physical mass that houses both the sword and the walking stick can be
identified independently of either. If this were not the case it is
difficult to see how one could even make the mistake of thinking of it
as one thing. The composites Siamese entities form are quite
identifiable, and yet that entity is not supposed to fall under a
sortal in its own right.



The ontological status of complex bodies and 'masses of
matter' (in Locke's phrase) is an issue very much under
dispute and we shall return to it below.


#### 3.3.2 The 'is' of constitution



A statue and a lump of clay occupy the same place at a given time.
What is their relation to each other? The apparent options are (i)
they are identical (ii) they are not identical, but the clay
constitutes the statue. (i) appears to be ruled out because they have
different identity conditions. (ii) has seemed to many philosophers to
be the natural solution to the problem, but it, too, faces
difficulties. First, it has the intuitive disadvantage that it
allocates two solid physical objects to the same place. Each of them
weighs, say, ten pounds, yet the total of their weight is only ten
pounds. It might seem natural to think--and it was formerly a
well established maxim--that there can be only one solid physical
thing at one place at a given time. Someone impressed by the idea that
two bodies cannot be in the same place at the same time might think it
more natural to say that there are two different ways of
conceptualising the material presence at that point, than that there
are two material things. That way it is easy to see why two ten pound
objects need not add up to twenty pounds when put together.



Second, the language of constitution is more natural if the situation
is described in some ways rather than others. It is natural to say
that the statue is made of clay or even from *a piece* of clay.
But suppose one characterises the clay more exactly, in terms of the
particular atoms in a particular arrangement. Strictly, on modal
grounds, this structured collection and the statue are different. The
statue could have been made of a collection of atoms with at least
some different members, but the entity defined as containing just
those atoms could not. This entity--atoms
A1...An in given spatial arrangement
S--is not a very natural kind of object, but it is a real body,
in a way that something arbitrarily composed of, for example, half of
this table and two toes from President Bush's left foot is not.
This collection of atoms in this structure is what investigation would
show to be really there. Though it is natural to say that the statue
is constituted by the atoms, it is less natural to say that the atoms
and the structure taken together, are what it is made from: rather it
might seem natural to say that that is what it *is*. To use the
Aristotelian terminology, there is strong pressure to say that atoms
and structure together are matter *and form*, and hence are the
complete individual.



All these issues are very controversial, and different philosophers
have different intuitions (see, for example, Rea 1997). But, if one
were to conclude that the statue and the lump are neither identical
nor stand in the constitution relation, what else could one say? One
strategy is to take the notion of *body* or *material
object* as basic. In the next section, this possibility is
compared with other options.


#### 3.3.3 A possible reconciliation of Wiggins and Ayers.



As we saw above, for Wiggins the concept 'body' is always
generic, never sufficient in its own right to sustain identification,
needing to be filled out by appeal to a more determinate sortal, such
as 'dog' or 'table'. Call this
'sortalism'.



For Ayers, on the other hand the notion of a coherent, unified body or
material object is the basic notion for individuating objects and is
presupposed by sortal concepts. It is only in so far as dogs and
tables are unified bodies that these notions can be used to
individuate objects. Call this 'somatism'.



We saw, briefly, in
 section 3.3.1,
 why Wiggins and Ayers think as they do. Although van Inwagen's
position is different from both, his reasons for thinking that the
concept of a *complex* body is, of its own, an inadequate
concept, are consistent with Wiggins's claim that the idea is
too determinable to function in its own right. Van Inwagen, therefore,
more directly challenges Ayers. (For a brief discussion of van
Inwagen's argument, see
 section 3.4
 below.)



How might we choose between sortalism and somatism? The dispute
between them can seem difficult to pin down. Perhaps an irenic
compromise is possible. Metaphysically, this compromise favours the
somatist, but seems to give the sortalist everything he should want.
The principle of the compromise is that Wiggins's formal
argument is correct: and hence it is necessarily true that Relative
Identity is not possible. But it is only a contingent truth that the
terms that can substitute for *F* in his formal proof are
generally--but not always--sortals of an Aristotelian kind.
Anything can be substituted for *F* that picks the object out
as a unified body.



Take Wiggins's formula, *a* =*F*
*b*, where it is assumed that the *F* is a material
object (not God or a spirit etc). The following theses might plausibly
be maintained.


1. For any identifiable and re-identifiable object, there must be
some predicate *F* that applies to it in a present-tense manner
through the whole of its existence, and that, by its meaning, picks
the object out as a unified physical whole.
2. All natural ultimate sortals designate unified physical bodies in
the manner prescribed in (1), and so are very suitable as
substitutions for *F*. It is logically possible, however, that
this might not have been so (there might logically have been natural
sortals that worked like *sword-stick*), but that they do
follow this model, and are not like sword-stick, is a pretty deep fact
about our world and about any world with similar laws of nature to
those that hold in our world.
3. Artefactual sortals generally designate distinct, unified bodies
(as do 'sword' and 'walking stick' in the
ordinary cases), though exceptions (as in the case of the sword-stick
considered above) are more common and less fantastic than in the
natural cases.
4. There are acceptable substitutions for *F* that would not
normally be classified as sortals, but using concepts such as
*piece*, or *hunk* or *lump of stuff*. In at
least some of these cases, there is no sortal available.
5. '[Unified] body' could always do the job of
*F*, because other, more specific, terms work just because the
things they designate are unified bodies. On its own, 'same
body' is just not very explanatory.



The account given in these five points has the advantage that it is
compatible with the fact that most identities involving
reidentification are categorisable under sortals, but that there are
other cases--such as 'piece of...', 'hunk
of...'--where this is not so. It also avoids the need
to employ the '"is" of constitution' to link
sortals and particulars, like lumps and hunks, rather than just mass
terms, such as 'clay' or 'gold'. The case
where the lump and the sortally individuated object do not coincide,
applies only to some problematic artefactual cases, and in those cases
the sortal name of the artefact will not be suitable substitute for
*F*, but the 'lump' expression will be. In that
way, it will be possible to avoid the need to have two material
objects in the same place.


### 3.4 Contemporary hylomorphism



Since about the mid 1990s there has developed a debate covering
similar territory to that disputed by Wiggins and Ayers, but having
rather different roots. It claims to be a revival of a broadly
Aristotelian hylomorphism, but it comes mainly from disputes in
mereology.



David Lewis famously propounded the doctrine of Unrestricted
Composition: that is, any combination of things in the world
constitutes a further thing (e.g., 1986, 211). So my left foot and any
arbitrary stone at the bottom of the sea constitutes an object, though
an object of no descriptive or explanatory interest. In the opposite
corner, Peter van Inwagen (1990) denied that there was any such thing
as composition, at least for inanimate material objects.



Van Inwagen's main argument is that necessary and sufficient
(particularly sufficient) conditions cannot be given for the kind of
cohesion of parts that is supposed to bind atoms into complexes. None
of the standard candidates--contact, fastening, adhesion, fusion,
nor any acceptable disjunction of them--will suffice. They all
have counterexamples. So the notion cannot be well defined. The
arguments are subtle and interesting. The question might be raised
whether van Inwagen gives sufficient consideration to the possibility
of taking a line similar to that taken by Putnam on natural kinds. One
fixes putative paradigm cases of non-living complexes, and says that
the kind of cohesion required is whatever sort of bonding holds in
those cases. It seems unlikely that there will not be a reasonably
tidy, scientific account of how atoms bond. Nevertheless, van
Inwagen's mereological nihilism has a stopping point, namely
that he believes that he, though a composite material object, really
does exist. So organisms do exist.



Van Inwagen's unwillingness (unlike the early Unger (1975)) to
apply the nihilism to himself, and others like him, prompted the
thought in other philosophers that there may be a way of having a
doctrine of Restricted Composition on the basis of being things of the
right kind--namely having a structure of the right kind--and
that this idea resembled Aristotle's notion of form and his
doctrine of hylomorphism. Philosophers following this line of thought
included Fine (1999, 2010), Johnston (2006), Lowe (2011), Koslicki
(2008), Rea (2011) and Jaworski (2011, 2012). It is difficult to
provide a compact account of these philosophers' positions, as
it can seem that all they have in common is a belief in some form of
restricted composition and a sense that the Aristotelian label
'hylomorphism' helps to give their theories a pedigree. My
strategy here will be to illustrate modern hylomorphism mainly using
the examples of Jaworski and Johnston, then citing a major problem for
any theory of this general kind, and illustrating this by reference to
Marmodoro (2013), where good discussions of Lowe, Koslicki and Rea can
be found.



If there is a single notion that plays a role in the rationale of the
restriction of composition, it is probably *structure*. Jaworski
probably deploys this notion in the most straightforward way. He and
Rea both use the following illustration. If you compact a human being
in a machine or waterproof bag, you retain the same matter, but lose
the human being, because you have destroyed the structure. Structure
is, therefore, a real and essential element in many or most complex
objects. He explains his theory as follows. 



> 
> 
> Hylomorphism claims...[t]hat structure is a basic ontological and
> explanatory category. (2011: 169)
> 
> 
> 
> Structure is also a basic explanatory principle in that it explains
> why members of this or that kind are able to engage in the behaviors
> they do. It is because humans are organized as they are, for instance,
> that they are able to speak, to learn, to engage in the range of
> activities that distinguish them from other living things and from
> non-living ones. (2011: 172)
> 
> 
> 



I think all the hylomorphists would agree with these statements, but
they each have their own way of stating the theory and it is not easy
to fit them together. Johnston's central account is as follows.




> 
> 
> A statement of the genuine parts and principle of unity of an
> item...takes the following canonical form:
> 
> 
> 
> > 
> > *What it is for*...(the item is specified here)...*to
> > be is for*...(some parts are specified here)...*to have the
> > property or stand in the relation*...(the principle of unity
> > is specified here).
> > 
> 
> 
> 
> As in: *What it is for* this hydrochloric acid molecule *to be
> is for* this positive hydrogen ion and this negative chlorine ion
> *to* be bonded together. ... The idea that each complex item
> will have some such canonical statement true of it might be fairly
> called 'Hylomorphism'. For it is the idea that each
> complex item admits of a real definition, or statement of its essence,
> in terms of its matter, understood as parts or components, and its
> form, understood as a principle of unity. (2006: 658)
> 
> 
> 



But Johnston's notion of a 'principle of unity'
turns out to be so generous that his theory almost collapses into
Lewis's.



> 
> Consider then all the myriad ways of constructing putative wholes from
> items gravitationally related to other items. Are they all genuine
> wholes? Given Hylomorphism, there does not seem to be any happy way to
> insist that they are not all *wholes*, even though very few of
> them will be material objects or stable physical systems...A
> whole consisting of your eyeglasses and Pluto is too far from [normal
> physical object] paradigms in respect of compactness and maximality to
> count as a genuine whole in the ordinary sense. But it is fully,
> completely and *genuinely* true that it is a whole. (2006: 697)
> 



One might wonder whether such an apparatus preserves what one might
want to save from a common-sense notion of composition.



A general worry about the hylomorphist approach might be put as
follows. The modern hylomorphists do not claim to be interpreting
Aristotle, but to be inspired by his concept of form. This means that
it is out of place simply to argue that they have not interpreted him
in a scholarly fashion. Nevertheless, it is relevant to point it out
if they have totally misunderstood his deployment of the concept of
form, for if this is the case, it might suggest that they are
pretending to a solution to the composition problem that they do not
possess. Someone who was sceptical about their claim to a solution
might start by pointing out that all the moderns reject the
'traditional' Aristotelian idea that form has a role as an
efficient cause, actually making a difference to the way that its
matter behaves. They deny this because they all want their theories to
be consistent with the closure of the world under physics. At the same
time, they seem to intend their composites to have full ontological
weight, and to have causal efficacy.



Jaworski is particularly clear in emphasising that he is a **causal
pluralist** and that the structural level is in no sense
epiphenomenal or a mere logical construct out of the lower properties
(see his 2011: 174). But one might query whether this is consistent
with accepting the possibility of closure under physics. Such closure
naturally raises the question of the causal claims made for form or
structure, and, hence, for their ontological weight. The importance of
*explanations* at the level of complex structures is not
disputed, but whether these represent just ways of
*conceptualising* a fundamental level that we cannot normally
access, is another matter. Johnston raises this question (2006:
660-62) but leaves it unresolved. Jaworski insists on causal
pluralism, but admits "all forces are operating at a fundamental
physical level": This latter remark seems to concede that what
one has in fact is an *explanatory* pluralism, with causation
included in the domain of explanation, but all the brute *force*
is confined to physics. Johnston is keen to deny that
*explanation* is a subjective or psychological phenomenon, but
admitting this does not place explanation in the world, in the sense
in which the forces that actually make things happen are in the world:
it only gives them the Platonic objectivity of propositions or
theories. 



It seems that modern hylomorphism faces the following dilemma. The
following argument has appeal. 


1. The concept of structure is essential to all or most natural
sciences.
2. If something is essential to a valid mode of explanation or
understanding, then it should be conceived realistically.



therefore


3. There are real structures in the world.



But the following also has appeal.


4. It is sufficient for the concept of structure to be applicable
that elements be appropriately arranged in the world, and these
arrangements can be characterised without employing the notion of
structure. This could be done by specifying the spatio-temporal
location of the elements and their causal influence on each
other.



If (4) is correct, it looks as if, though our structural concepts are
well grounded in reality, structures are not part of the basic
furniture of the world. This is, in fact, the same issue as whether
Kim's exclusion principle applies to the special sciences: that
is, if physics gives a sufficient causal account of the location of
all matter, are the other sciences merely heuristics, but strictly
epiphenomenal? (see Kim 2005 and Robinson 2014). Perhaps the status of
form and structure cannot be solved in a modern context without
solving the exclusion issue. 



Anna Marmodoro (2013) argues that the modern hylomorphists have
misunderstood Aristotle in a radical fashion, in a way that is
directly connected with their concern about the unity and hence
reality of composites. She claims, with strong backing from the text,
that form is not structure, because it is not a combination of parts.
The essence of form is its unity, and its unity depends essentially on
the fact that the matter that comes to compose it loses its previous
identity. By contrast, in any kind of structure of parts this identity
is not lost; the parts are merely organised in a certain way.



On this interpretation, Aristotle must deny the core of (4), which is
that the behaviour of complexes derives necessarily from the primitive
causal powers of the elements and their spatial relations--this
is a 'bottom up' atomist principle., and presupposes that
the parts retain their identity within composites. But without this
core idea in (4), it is difficult to see how there can be
'closure under physics', for if the atoms did not retain
their identity, how could the nomic structure that rests on them be
preserved?



There seems to be, therefore, a tension between two principles the
modern hylomorphists seem to want to preserve. The tension is between
the role of form as the creator of a genuine, non-conventional unity
in composites, and an openness to the modern belief in the closure of
the world under physics.



Marmodoro's concern about Aristotelian unity also indicates a
difference between hylomorphism and the actual nature of substances,
namely concerning the vagueness that attaches to most of our substance
concepts. For most of our concepts, there are paradigm cases, but also
marginal cases. This is an almost inevitable consequence of taking
seriously the atomic constitution of objects, for there will be no
very neat constraints on how they might combine. There are many
theories about how one should react to vagueness, but one of the most
common and intuitive is to say that it is a conceptual
matter--reality itself cannot be vague. This tends against a
realist and in favour of a conceptualist approach to our substance
concepts: if our macro-substance concepts are prone to
vagueness, and if vagueness is a sign that the concept in question is
not to be taken in a realist fashion, then Locke would be right that
what we normally regard as substances are just our ways of classifying
things.



This conceptualist approach is reinforced if one accepts both what has
been called the Eleatic Principle, namely that something can be a
real, concrete entity only if it has causal powers of its own, and,
that the physical world is "closed under physics". The
latter entails that only the entities of physics influence the
distribution and motion of matter, so that higher-order entities,
though they may figure in essential forms of explanation, have no
influence on that on which everything physical supervenes. Applying
the Eleatic Principle to this, macro "entities" are not
real in the way that anything worth calling hylomorphism, in the
Aristotelian tradition, requires (Robinson 2016: Part II).


### 3.5 Substance and teleology



There is one mark of substance that was important to Aristotle that we
have not discussed. This is the connection between substance and
teleology; that is, the notion that *what something is* is
intimately connected with its natural purpose, end or function. The
association with teleology does not naturally recommend itself to the
modern mind. Wiggins, for example, says that "it would have been
both possible and advantageous for Aristotle to distance [his account
of substance] from his concern with final causes..." (2001:
80). The concern with teleology is presumably thought to be too
closely connected with Aristotle's theology, or the idea that it
is divine design or intelligence that gives natural objects their
ends. Nevertheless, it is not easy for an Aristotelian to make a
complete break from teleology. Teleology is what distinguishes living
things that act for purposes and have organs with functions from lumps
and rocks, and it is the former that Aristotelians see as the paradigm
substances. It is no accident, therefore, that artefacts, which are
generally defined by their function, are often cited as good
illustrations--even if not paradigm cases--of substances. So
we have a tension developing. On the one hand, lumps and rocks are
good paradigm cases of our notion of natural enduring objects. But
they are bad cases of objects with purposes or ends. Artefacts are
good cases of things with purposes, and are reasonably enduring, but
are not natural objects. Living things come near to getting the best
of both worlds. They are natural and enduring, and they have purposes,
in the sense of natural goals in their behaviour. (Although, according
to the modern perspective they do not possess a final end, unlike
artefacts: a knife is for cutting, but there is nothing a dog is
*for*, though it has many ends *en passant*.)



This teleological approach to substance could be expressed as
follows.


8. The substances in a given system are those entities crucial from
the teleological or design perspective of that system.
'Crucial', here, means that other things exist either to
constitute them or to provide a context of operations for them.



The tension between the teleological mark of the substantial and the
others we have considered might make it useful to distinguish between
*descriptive ontological priority* and *teleological
ontological priority*. The former is interested in a purely
descriptive account of what exists, and it, therefore, rates as the
substances those entities that a purely descriptive science would
count as basic. The latter, however, counts as substances those things
that are deemed fundamental because of the role or function they play
in the world. This contrast is most plain in the case of artefacts. An
artefact is made of its parts, and, in a sense, they are more basic
than it because they constitute it. But if there were not artefacts of
the appropriate kind, those parts would never have come into
existence: if there were no motor cars, there would be no steering
wheels or accelerator pedals. Thus, like Aristotle's severed
finger (*Metaphysics* 1035b 23-5), these latter do not
count as substances. But it is not true that the parts would not exist
without the whole if one takes *parts* right down to the
natural elements and atoms that make the artefact. Then one has a
conflict about what is deemed basic between the descriptive and the
teleological criteria. It is to avoid this conflict that Aristotle
rejects atomism, by allowing that there are no true entities, only
stuffs, more basic than those he wants to treat as substances by the
criteria of teleological significance. He avoids having to face the
problem that one set of things is basic or substantial descriptively,
namely the atoms from which everything is constituted, and another set
of things--the macroscopic objects of our ordinary
lives--are substances by the criterion of teleological
importance. Because matter is stuff, not individuals, the objects that
are teleologically important are also the descriptively basic objects,
because what they are made of are not objects at all.



It could be argued that atomism can be reconciled with treating the
things that are significant for us as substances only if one thinks of
the atoms as existing only in order to constitute such objects. This
would be so if God had created the atoms so as to construct
macroscopic objects from them, just as we create the parts of
artefacts only for the sake of the artefacts. It might be argued that
the same objective could be reached without theism if there is
irreducible teleology in nature that gives significance to the rest.
Thomas Nagel's view in his (2012) either adopts or comes close
to this position. But Nagel's position seems to challenge
natural science within its own realm, whereas the "theological
artefact" model does not. It is uncontroversial that an
artefact, such as a clock, can be both mechanical and defined as the
kind of thing that it is by its function. Applying this model to
nature as a whole would involve bringing theology into
Aristotle's metaphysics more directly than he, or indeed
Aquinas, intended. The notion that an object is what it is because of
its use is found in Heidegger (1927 [2008]) but this is the use to
which we put objects, not a divinely ordained teleology;
Heidegger's theory imports the subjective perspective implicit
in phenomenology, and this runs counter to Aristotle's
objectivism. If, however, one takes the teleology to be designed into
creation, this subjectivism is eliminated, and if one thinks that
teleology is the key determinant of substantial identity, as with
artefacts, then one has preserved the doctrine of substance, rather
than replacing it by a mere theory of function. This would have the
consequence that if the designer could change the purpose of an object
whilst leaving it physically unchanged--as we do if we use a
knife as a screwdriver--then its substantial identity will change
(Schillebeeckx, 1968, Dummett, 1987, Robinson, 2016)


## 4. Conclusion



All non-relativist philosophical systems acknowledge substances in the
most generic sense of that term, for that is only to acknowledge that
there are some fundamental entities in their system. Most, if not all,
philosophers acknowledge that we cannot function without using
substance concepts in the narrower sense, for the notion of an
enduring particular or individual substance is essential to our making
sense of the world as we live in it. But three things at least remain
controversial. First, it is disputed what kinds of concepts need to be
deployed to characterise these enduring things: are they the rich
variety of traditional or 'Aristotelian' substance
concepts, or will various ways of identifying things simply as
physical bodies with certain characteristics do the job? Second, it is
still unclear how far our substance concepts purport to reflect a
component in reality (real or imagined) over and above the bundle of
properties that constitute its intelligible aspects. Third, the
unclarity of the connection between *what a thing is* and
*what it does* leaves unresolved the degree of interdependence
between substance concepts and notions of purpose and final
causation.