The Symmetry Thesis: A Neo-Lockean Defence

need
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more than the Generality Constraint. In the next section I offer what I
take to be a more powerful defence of the Symmetry Thesis. In one respect
this defence will be wider in scope than the Strawson and Evans argument,
because it will not be restricted to conceptual thought. In another
respect, though, it will be narrower in scope, because it will not support
a strong reading of the Symmetry Thesis.
9.2 The Symmetry Thesis: A Neo-Lockean Defence
The argument in support of the Symmetry Thesis that I will offer in this
section is much briefer than the unsuccessful argument from the Generality
Constraint just examined. It starts not from putative requirements on
concept mastery and psychological self-ascription but from a point about
self-awareness that has already been discussed. This is the point that selfawareness
has a fundamentally contrastive dimension. The contrastive dimension
of self-awareness had an important part to play in developing
the notion of a nonconceptual point of view. At the core of the notion of
a nonconceptual point of view is the capacity to distinguish self from the
environment, and the richness of the self-awareness that accompanies this
capacity is directly proportionate to the richness of the awareness of the
environment from which the self is being distinguished. A similar thought
is the key to seeing why the Symmetry Thesis is true.
Let me begin, though, by bringing out in a little more detail what I
mean by the contrastive dimension of self-awareness. As I have emphasized,
an important element in self-awareness is a subject’s capacity to
distinguish himself from the environment and its contents. I will use the
phrase ‘distinguishing self-awareness’ as a shorthand for this. The discussion
of somatic proprioception in chapter 6 provided a clear example of
distinguishing self-awareness. I showed how an awareness of the body as
a spatially extended object distinctive in virtue of its responsiveness to
the will was part of the content of somatic proprioception. As I noted,
however, this awareness is only a limited form of distinguishing selfawareness,
yielding little more than a basic distinction between self and
nonself. The reason for this awareness being so restricted is simply
that somatic proprioception does not implicate (though, of course, it can
be accompanied by) a particularly rich conception of what the self is
Psychological Self-Awareness: Self and Others 237
opposed to. The conception of the environment emerging from somatic
proprioception need not be anything richer than what is not responsive
to the will, and this yields little more than a conception of basic numerical
distinctness. Clearly, if a richer conception of the environment were
in play, then the distinguishing self-awareness in somatic proprioception
would be correspondingly richer. For example, if a subject were able to
conceive of his environment as containing spatially extended objects, then
he would be capable of distinguishing self-awareness as a spatially extended
object that is distinctive within the class of spatially extended objects.
The significance of possession of a nonconceptual point of view is
precisely that it provides a richer awareness of the environment, thus making
for a correspondingly richer degree of distinguishing self-awareness.
There is, I conjecture, a general principle to be extracted here. Distinguishing
self-awareness implies tacit reference to what might be termed a
contrast space. I have distinguishing self-awareness of myself as f only to
the extent that I can distinguish myself from other things that are f. These
other things that are f form the contrast space. This principle about
contrast spaces can be seen as an extension of a familiar neo-Lockean
point about identity (Mackie 1976, chap. 5; Wiggins 1980; Ayers 1991,
vol. 2).
The neo-Lockean point about identity is that questions about identity
over time can only be posed and answered relative to a given categorization.
It does not make sense to ask whether something that exists at a
particular time is or is not identical with something that exists at a later
time. What we have to ask is whether this thing is the same x as that
thing, where ‘x’ is a sortal representation that picks out a category or
kind. A sortal representation, as I propose to use the term, is a mental
representation, not necessarily linguistic, that classifies things as members
of a given kind. The kind in question may, but need not, be a natural kind.
What distinguishes a sortal representation from an ordinary descriptive
or functional representation is that it is associated with more or less determinate
criteria of application and identity, from which it follows that
once we have a given sortal representation in play, we will know what
criteria of identity to look for. Of course, distinctness being the opposite
of identity, it follows that we cannot ask simply whether this is or is not
distinct from that. What we must ask is whether this is a distinct x from
that, where ‘x’ picks out a category or type of object.
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Let me term the Lockean thesis the restricted thesis of relative identity
over time. To hold the restricted thesis of relative identity is to hold that
questions of identity over time are always relative to a given sortal representation.
This needs to be kept separate from the unrestricted thesis of
relative identity over time, according to which two individuals x and y
may be identical with respect to one sortal representation but distinct
with respect to another. Let me illustrate this with the very relevant example
of personal identity. Locke’s view (which I am not endorsing) is
that a single block of flesh and bone can embody two different countable
things: a living human being (relative to the sortal representation man)
and a conscious rational subject capable of memory (relative to the sortal
representation person). The man and the person are different things that
happen most of the time to be physically coextensive. This is a form of
restricted relative identity. According to the unrestricted theory of relative
identity, on the other hand, the block of flesh and bone is identical
with the man and also identical with the person, although the man is
not identical with the person. Two good reasons for not endorsing the
unrestricted thesis are, first, that it comes into conflict with the principle
(Leibniz’s Law) that if x and y are identical, then they share all their properties
and, second, that it means abandoning the transitivity of identity.
Fortunately, the unrestricted thesis is not entailed by the restricted thesis.4
To reach the unrestricted thesis, one needs to add to the restricted thesis
the premise that an individual can be a member of more than one kind,
where the kinds in question are not subordinate to one another.
Locke himself believed that questions about identity and distinctness
(or diversity, as he put it) were problematic only when considered over
time. Recent work on personal identity has not followed him in this. Consideration
of split-brain patients in particular has suggested that identity
and distinctness at a time can also be very problematic.5 For example, one
(admittedly rather controversial) way of considering split-brain patients
would be to hold that at any given time after the severing of the corpus
callosum, a block of flesh and bone can embody more than one conscious
rational subject, despite embodying only one living human being.
Whether or not this is a correct description of split-brain patients, it is
a conceivable possibility that theories of personal identity need to take
account of by incorporating some of sort of means to answer questions
of identity at a time. Presumably, this will require applying criteria of