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23 Locke, Essay II.xxvii.1-14 Identity Locke’s chapter on the idea of identity carried
implications that were even more disturbing for many of his contemporaries
than were his views on substance. Over
the course of the chapter, he developed a distinction between the body (or
“Man” as he called it), the soul (or spirit), and the self (or person), and
he argued that the self is radically distinct from both the body and the soul
— so radically distinct that, in principle, the self could be conceived to
change the soul in which it inheres as easily as bodies change their clothes,
and souls could be inhabited by a succession of different persons over
time. As Locke understood it, the self
is the collection of our sensations, thoughts, desires, and volitions,
whereas the soul and the body are substances.
On this view the self is fragile. Rather than be intrinsically capable of
existing on its own, as a substance, it is merely a complex mode. This account rendered worries about the
immortality of the soul and its distinction from the body entirely moot. Even if the soul were immortal and distinct
from the body, it would not follow that the self survives death. QUESTIONS
ON THE
1. What is requisite if
we are to be sure that one thing is different from another, e.g., that
someone has a twin?
2. What are the three
kinds of substance?
3. Why is identity not a
problem where God is concerned?
4. Are there any
exceptions to the rule that two different things cannot be in the same place
at the same time?
5. Under what condition
would our ideas of identity and diversity have no foundation and be of no
use?
6. What determines the
identity of particular instances of modes or relations and distinguishes
different instances of the same mode (e.g., different right-angle isoceles
triangles of the same colour and size) from one another? What sorts of modes and relations can have
no identity?
7. If a mass of atoms has
its parts rearranged, is it still the same mass? If it loses or gains a part, is it still
the same?
8. What makes an oak tree
different from a mere mass of matter?
9. What distinguishes one
plant from another of the same species, e.g., one oak tree from another? 10.
What determines that the organization of life-function
performing parts that is present at any one instant in any one collection of
matter is identical to one earlier or later organization of life-functioning
parts characteristic of that species of plant rather than some other, e.g.,
that the bush in this pot in winter is identical to the one that was in the
garden in summer? 11.
How does the identity of animals and plants differ from
that of machines? 12.
What is wrong with supposing that what makes people the
same from one moment to the next is that they look the same? 13.
What is wrong with saying that what makes someone the same
human being from one moment to the next is that they continue to possess the
same soul? 14.
What was Locke trying to get at at II.xxvii.8 by claiming
that a creature with a human body will always be considered a human being,
even if it is so impaired as to be incapable of thought or sensation, whereas
a cat or parrot who could speak and philosophize would still be considered a
cat or parrot? 15.
How do we distinguish our self from the selves of other
thinking beings? 16.
What determines how far my self exists backwards in time,
that is, what determines whether I will consider any past thought or action
to be identical with a thought or action of my self? 17.
Does identity of self presuppose identity of thinking
substance? 18.
What grounds do we have for affirming that the same person
cannot be successively present in different thinking substances? 19.
What grounds do we have for affirming that different
persons could be successively present in the same thinking substance? NOTES
ON THE Unlike the idea of substance, which is a
complex idea, our idea of identity is the idea of a relation that we find
between ideas when we compare them with one another. At its most basic, this relation is the
relation of being exactly alike in all respects. We can call this strict identity, and we
can say that the idea of this relation arises in us when we compare one thing
with itself, and discover absolutely no differences whatsoever. For example, I might compare a chair with
itself, and assert that it is identical with itself because the comparison
discovers no differences. However, Locke was worried about a different
sense of identity: identity over time. The difference between these two senses of
identity can be illustrated by an example.
When the victim of a crime points to one of the people in a police
line-up and says: “That is the one,”
we say that the victim has identified the perpetrator. But the individual who has been identified
cannot possibly be exactly identical in all respects to the individual who
committed the crime, if for no other reason than because the individual in
the line-up is older than the person who performed the crime, if only by a
few hours, and occupies a different place in space, the police line-up rather
than the scene of the crime. We think that objects can continue to exist
over time, and that an object existing at a later time can be, as we say,
“the same as” or “identical to” an object existing at an earlier time. But this notion of identity over time is
importantly distinct from strict identity.
We do not think that a later thing has to be exactly identical in all
respects to an earlier thing. Later
things can look very different from earlier things and still be thought to be
identical to them. Think of earlier
and later states of the same fire, the same acorn/sapling/oak tree, the same
egg/tadpole/frog, or the same infant/child/adult. Moreover, later things that look to be in
all respects identical to certain earlier things may in fact be different
from them, for example, the chairs in one classroom today, and those in that
classroom tomorrow. But if resemblance
does not determine identity over time, what does? Locke approached this question by first
observing that our notion of strict identity entails that no two things of
the same kind can be in the same place at the same time. (He added the qualification “of the same
kind” because we do think that things of different kinds can be in the same
place at the same time. For instance, a colour and a taste can be in the same
lump of sugar at the same time, though two different colours or two different
tastes cannot. And if spirits are
distinct from bodies, and spirits can be located in space, as Locke was at
some pains to argue in Essay
II.xxiii, then a spirit and a body might be in the same place at the same
time.) When you take your idea of what
exists in a given place at a time and compare it with your idea of what
exists in that place at that time you see no differences whatsoever. So your idea is one, strictly identical thing,
not two different things. Presumably,
since it is just one thing, it can only be in one place at any later
time. (Were it capable of splitting in
two, it would have had to consist of two parts set outside one another at
different locations in space to begin with and we should have been considering
just one of those atomic parts. The
case of plant and animal generation will be considered below. For now, let us just focus on particles.) So whatever later things can be traced back
to this thing must be identical with it.
As he put it, whatever later things have the same “beginning of
existence” (whatever later things originated from the same place at the same
time as some other thing) must be identical to that thing and to one another. Locke’s proposal for dealing with identity
over time is not that different from that employed by the police when
attempting to identify the perpetrator or a crime. If a suspect turns out to have been in a
different place at the time the crime occurred, that person is eliminated
from suspicion, because no one can be in two different places at the same
time. But if the investigation is able
to trace the suspect’s history of motion and rest right back into the
footprints of the perpetrator at the time of the crime we think that the
investigation has identified that suspect as the perpetrator, and that no
further investigation of the other suspects is called for. For, just as nothing can be in two
different places at the same time, so no two things of the same kind (in this
case, no two different people) could be in the same place at the same
time. So, identifying just one suspect
as the perpetrator automatically eliminates all the other suspects from
suspicion, even in the absence of independent exoneration. The two principles just mentioned, – nothing can be in two different places at
the same time – two different things of the same kind cannot
be in the same place at the same time imply that each distinct thing that now exists can be traced back to one and exactly one place, not occupied by any other thing of the same kind at each past moment of time. For, were it possible to trace two distinct things of the same kind back to the same space at some past time strict identity would be violated, since what exists in a place at a time is exactly the same as itself in all respects and so one and not two. And were it possible to trace one thing back to two different spaces at the same past time, then there would be one thing in two different places at the same time, which is impossible. From these reflections we can obtain both a principle of individuation and a principle of identity: Principle of
individuation:
whatever is in two different places at the same time is two different things Principle of identity: anything with a history that puts it
in the same place at the same time as some earlier thing of the same kind is
the same with it. Locke
laid this account out succinctly in II.xxvii.1 That therefore that had one Beginning is
the same Thing, and that which had a different Beginning in Time and Place
from that, is not the same, but divers. [Essay
II.xxvii.1] As thus presented, Locke’s account of identity
is dissatisfying. The account appeals
to the notion that the way to determine whether one object is the same as
another is to find out whether it had the same beginning of existence. But how could we do that? Above, I alluded to studying the object’s
history of motion and rest. But motion
and rest are things that happen over time.
To determine whether a thing is moving or at rest, I have to be able
to identify where it is from one moment to the next. If I have to be able to identify things
from one moment to the next in order to determine their history and motion
and rest, then I can’t take their history of motion and rest to be what
determines their identity over time.
That would get me caught in a vicious circle. This is not an issue that Locke explicitly
addressed. Perhaps he would have said
that as long as we allow that “splitting” and “joining” are not possible
(that what is one thing, existing in one place at one moment cannot, at a
later moment, exist in two different places at the same time, and that what
is two things, existing in two different places at a moment cannot, at a
later moment, come to both exist in the same place at the same time), then
each thing that exists at any given moment will necessarily be identical to
at most one thing existing at any later moment. Nothing needs to “make” it identical. Its bare continued existence over time
suffices for that to be the case. We
might have problems telling which
of a number of similar later things is the one that is in fact identical to
an earlier one, but that is an epistemological problem, distinct from the
metaphysical question of what makes a thing the same thing from one moment to
the next. The answer to the
metaphysical question is that what makes a thing the same from one moment to
the next is nothing more than its continued existence through time. As Locke put it, “For
being, at that instant what it is, and nothing else, it is the same, and so
must continue, as long as its existence is continued: for so long will it be
the same, and no other.” (Essay
II.xxvii.3) The
implication of this answer is that we do not need to invoke a special notion
of substance as something that is uniquely able to persist over time and that
binds the successive states of changing things together. The bare existence of a thing suffices for
that purpose. This still leaves the epistemological question
of how we could know which later things are the continuations of existence of
which earlier things, and that is not a question Locke could afford to leave
unresolved. He considered identity to
be a primarily “forensic” notion. We
make use of it to determine who, among the people existing now, is
responsible for crimes committed at an earlier time. This means that identity relations have to
be ones we can come to know. And we
can’t come to know them by applying the metaphysical criterion of taking
continuity of existence to determine identity. This is because the only way we can tell
which later things are continuations of which earlier things is by applying
some criterion for determining identity over time, which remains something that
we are lacking. An obvious suggestion is that we might
determine identity by experience. If
you have kept an eye or hand constantly on the object, so as to observe it
from one moment to the next, then we can be assured by experience that it is
the same. Once you have learned what
objects are the same in this way, you get an idea of how different sorts of
objects move and change over time, and then you can simply appeal to that
knowledge on subsequent occasions to make informed guesses about which objects
are the same or different based on degrees of similarity or changes in
position. It might be objected that this approach is
just as question-begging. The question
is what makes things identical over time.
I am a thing too. So I need to
know what makes me identical over time before I can invoke my earlier and
later visual and tactile sensations in order to determine the identity of
other things. But when it comes to our own existence over
time, we have a kind of intuitive certainty that we lack in other cases. Remembering the past experiences of someone
else isn’t an option. My memory gives
me immediate access to my own past experiences and no one else’s, and this is
the case for all of us. Each of us can
remember at least some of what happened to them in the past. None of us can remember what happened to
any one else. When it comes to other
people, we need to draw on other means of discovering what they did in the
past. We cannot have their memories
for them. This makes memory a kind of
operation that uniquely individuates me from all other past people. The past person I take to be identical with
myself is the unique past person whose experiences I can remember. And because I have that kind of certainty
of my own identity over time, I can rely on it in declaring that I
continuously observed a particular object over a certain stretch of time and
am therefore certain that this particular object is the very one that is
identical with one that existed at an earlier time. A further basis for judgments of identity
might be taken to be the supposition that all change in nature must be
continuous (that there can be no gaps or jumps, so a thing cannot cease to
exist at one place and then pop back into existence somewhere at some later
time, or leap from one place to a separate one next without first taking a
path across the interval, or suddenly change from being one way to being
another way). If this is so, then,
considering very small intervals of time and space, we ask which of the
objects in the small spaces surrounding the spot a given object occupied at
the fractionally earlier time, is the one that most resembles the given
object. In cases where there are two
or more such objects, we look at yet smaller spaces at yet shorter
times. In cases where this does not
help, we remain genuinely confused about which object is which, but this only
happens rarely. Otherwise, our default
assumption is that objects that most closely resemble over smallest spaces
and times are identical. In practice, determining identity in this way
is tantamount to determining identity by keeping an eye or a hand constantly
on the object. Both rest on personal
past experience and memory of that past experience. In laying out this position on how we might determine a thing’s history of motion and rest I have gone beyond the letter but not the spirit of Locke’s account. But we are not entirely out of the woods because the account given so far only applies to indivisible things — physical atoms or minds, supposing that they are simple — and composites with parts that remain at the same locations relative to one another over time. The rule for the identity of such things over time would be a direct application of the historical criterion. If a study of the past history of motion and rest of a given body shows it to have occupied the same place at the same time as some other body, then those two bodies are identical, and the first is a later state of the second; otherwise, they are distinct. However, the fact that bodies and souls are
different kinds of things means that, were we to trace the history of a body
back to an earlier time when it occupied the same place as a particular soul,
we would not consider the body to be the same as the soul. Things that occupy the same place at the
same time are identical only if they are of the same kind, that is, if they
are both bodies or both souls. Of course, there is no danger of our ever
identifying a body with a soul because these are radically different kinds of
things, and the distinction in kind serves to prevent us from considering
them to be the same. (Even
materialists only deny that there are souls, they do not identify them with
atoms.) However, the fact that a body
could occupy the same place as a soul without the two of them being
considered to be identical means that, at a later time, the body and the soul
could move off in different directions and the body come to occupy the same
place as some other soul while the soul comes to occupy the same place as
some other body. Otherwise put,
reincarnation, the act of a soul leaving its “body” and coming to occupy a
series of different bodies in succession is at least a logical possibility. Identity
of Compound Bodies. The simplest way to deal with the identity of compound
bodies is to take it to be a function of the identity of their component
parts: if all of the parts of a compound body are identical to all of the
parts of some earlier compound body, then those two compound bodies are
identical; otherwise, they are distinct. Locke did not say so, but, in practice, this
criterion often proves to be too strong. If a raindrop erodes a grain of sand
from a mountain, and so removes some of its atoms, we do not say that the
mountain becomes a different mountain, and is no longer identical to the
mountain that existed before the scrape.
Of course, there comes a point where the removal of material becomes
so extensive that we do not think that the same compound body still exists. This goes to show that there is a degree of
vagueness to our concept of the identity of compound bodies. There is no precise point at which identity
ceases and diversity begins. But there
are points at which it is obviously present (when no atoms have been removed)
and when it is obviously absent (when a significant proportion of them have
been removed). However, we are not always satisfied even if
exactly the same atoms continue to be present in a compound. If I have a watch and someone smashes it
with a hammer into a pile of rubble, all the atoms that were originally
present may continue to be there. Only
their manner of arrangement has changed.
Yet I am not inclined to say that the watch still exists. In this case, it is not just the continued
presence of the same collection of atoms, however they may be mixed or
arranged, that establishes identity. The manner of arrangement of the atoms must
also persist. This is not always the
case. A pile of laundry is the same
pile even if the clothes making it up are jumbled about. But in many cases rearrangement of the
parts of a compound is taken to destroy its identity. In some cases, the manner of arrangement of
the parts is so important that we are even willing to ignore significant
changes in the atoms that go to make a compound up, as long as the manner of
arrangement is preserved. This is the
case with the ship of Theseus, which over the years was wrecked and repaired
so many times that not one nail that was originally present in the ship
remained. Yet Theseus and his
companions continued to give the ship the same name and to consider it to be
the same ship they had sailed out in. As Locke understood it, these sorts of cases
show that we are not always concerned with the identity of substance (the atoms making up a
compound) over time. In many cases
(and machines like ships are a good example), we are more concerned that the manner of arrangement of the
substances persists over time, even if the individual substantial parts
arranged in this manner get exchanged
with other, similarly functioning parts.
(This manner of arrangement is what enables a machine to perform its
function, and that explains why we might be more concerned with it than with
the substances that make it up.) The manner of arrangement of substances is a mode.
Recall that modes, like substances, are collections of simple
ideas. But whereas substances are
collections of simple ideas that we come across in our perceptual experience,
modes are collections of simple ideas that we only ever think of in
conjunction with yet other simple ideas.
A sugar cube is a substance, being cubical is a mode. The collection of ideas that goes to make
up what we call a cube can only be perceived when we perceive some substance
that exhibits this mode. But we may
perceive different substances to exhibit the same mode. Locke observed that modes can persist even if
the substance changes. For example, if a compound body consists of a number
of parts of a certain shape, arranged in a certain fashion, and some of these
parts are removed and replaced by identically shaped and arranged parts, then
the mode of arrangement remains the same, even though the substance has
changed, for the mode just consists in the placement of shapes in a certain
order, and does not include any reference to what bears those shapes. This suggests that modes are amenable to
being identified and individuated in the same way as substances: We can say that any particular manner of
arrangement of substances that now exists at a certain place is distinct from
the identical manner of arrangement of substances now existing in some other
place. And we can conceive of these
different manners of arrangement as persisting over time and having histories
of motion and rest that establish their identity with their own earlier and
later states and their distinction from other complex modes of the same type.
This is what Theseus and his companions did
with their ship. They considered it to
be the same ship because what they were concerned with was the mode of
arrangement of the substances, rather than the substances themselves, and
that mode of arrangement had a history of motion and rest that individuated
it from other ships (or ship-shapes), and that gave it an identity over time
irrespective of the exchange of its parts.
Had the ship been totally dismantled and then rebuilt from scratch some
time later, then even if the rebuilt ship was an exact replica, made with
exactly the same parts, there would have been a break in the continuous
existence of that particular mode of arrangement of substances, and Theseus
and his companions would not have given it the same name or considered it to
be the same ship. Identity
of Living Creatures. What Locke said about the identity of machines applies to
the identity of living creatures: plants, animals and human beings. But some serious modification is required. Unlike machines, which merely exchange
their component substances over time as they break and get repaired, plants,
animals and human beings grow, starve, reproduce, occasionally suffer
accidents that result in a loss of limbs or organs, and even undergo radical
changes of form (say from egg to larvae to adult insect, or tadpole to
frog). Accounting for their identity
therefore poses further challenges. Locke thought that in these cases our
ascriptions of identity are still based on the continued persistence of a
mode over time, but that the mode is not a mode of arrangement of parts, but
something rather more complex: an arrangement of parts that work together to
preserve the same life. Here, “life”
is something that we take to consist in the ability to perform certain
functions such as respiration, nutrition, growth and reproduction,
locomotion, sensation, or understanding.
At any given moment a particular organization of parts that enables a
compound substance to be considered to be alive is distinguished from any
other compound substance, however similar, that exists in a different
collection of parts in some other place at that time. Then, whatever substances may flow into or
out of that compound over time, and however the organization of its parts may
change over time, as long as the same life functions continue to be performed
in that compound, the identity of the plant, animal or human being is
preserved. Thus, when a woman becomes
pregnant, we say a second life begins in a cavity inside her body at the time
when the fetus or embryo begins to perform its own life functions —
functions that make it alive insofar as they are performed but that
make no contribution to the life of the mother and so would not take away her
life were they removed from her.
Something similar can be said about the relation between all of us and
parasites or disease organisms that we might contain. For the same reasons, if an amoeba splits
in two, what we say is that the parent life is destroyed in giving birth to
two children. The case of people who “return from the dead”
is an odd one. Strictly applying Locke’s
criteria, it would have to follow that someone whose life functions cease, if
only for a few moments, and who is then resuscitated, is not the same living thing. The period of death breaks the temporal
continuity of the complex modes, creating two points of “beginning of
existence.” And no one thing can have
two points of beginning of existence. Such cases were unknown in Locke’s day, but he
would probably have dealt with them in the same way I conjectured he would
have dealt with scratches to mountains.
He would have said that there is a degree of vagueness in identity
ascriptions. Just as we would be
inclined to say that a mass of matter is the same notwithstanding the loss of
an inconsiderable number of its parts, so we are inclined to say that a life
has persisted notwithstanding an inconsiderable interruption. There is another case where quite considerable
interruptions can arise, and in that case Locke had recourse to an entirely different
criterion of identity from continuity in existence. Personal
Identity. Locke’s
reflections on the identity of modes led him to claim that though the idea of
identity is fundamentally the idea of the relation of originating from the
same point in space at a particular time, in different cases there are
different things that we attempt to trace back to a common point of
origin. When considering the identity
of physical atoms, souls, and masses of matter, it is the substance or
substances that we attempt to trace back to a common origin. But where the identity of plants, animals,
human bodies, machines, and other artifacts is concerned, it is not the
substance that we are concerned to trace back, but modes of varying
complexity — modes that may, for all we care, have been
transmitted from substance to substance over the time of their existence. Locke went on to observe that there is a
further case where this happens, the case of the identification of
persons. That Locke should have said
this might seem strange. After all, he
had already given an account of how we identify souls or minds from one
moment to the next, as well as an account of how we identify human bodies
from one moment to the next. What,
then, is left over for the term, “person,” to refer to, if not just one or
the other of these two things? The best way to grasp what Locke was worried
about is to recall the position he took on the identity of human bodies. He there said that I can be considered to
continue to have the same body even though all the atoms that go to constitute
that body might change over time.
I — what I consider to be my self —
could not therefore be identified with any particular physical atom or
collection of physical atoms that might at any time happen to be present in
my body or to constitute it or one of its parts. Were I to identify my self with my body,
therefore, I could not identify it with any atom or collection of atoms. I would have to identify it with a complex mode. Should we say, then, that I just am the
complex mode that constitutes my life?
That as long as the same life continues to exist I must continue to
exist, regardless of how my body might change over time? There is a problem with saying these
things. Recall that earlier Locke
allowed that, in principle if not in fact, souls might be conceived to be
coincident with different atoms at different times. Consequently my soul
could conceivably exist in different bodies.
If I take my self to be wherever my soul is, then my self could be in
different bodies at different times. But even if we deny that there are such things
as souls, there are reasons to suppose that the self might not always exist
where the body is. A series of thought
experiments can help to illustrate this point. We typically identify persons
on the basis of their human bodies.
For instance, when someone is hauled into court accused of a crime, we
determine whether they are guilty or not principally by determining whether
they have the same body as the criminal, often by appeal to characteristic
traces that only a particular human body can leave behind, like fingerprints
or DNA samples. But we do not really
think that the body performed the crime, any more than we think that the gun
or knife performed the crime. The body
is just an instrument used by the perpetrator, just like the gun or
knife. Suppose that the technique of
transplanting brains were perfected and that a criminal, just prior to
performing some crime, kidnapped an innocent person and had his brain
transplanted into that person’s body, used the person’s body to perform the
crime, being careful to leave DNA samples and fingerprints behind, and then
had his brain transplanted back into his old body. In this case we would say that even though
the DNA and fingerprint evidence proves that the kidnapped person’s body was
the body that performed the crime, the person
who had been kidnapped was not the same person
who had performed the crime. Though we
look in the first instance for the same body when attempting to identify
perpetrators, we do this only because brain transplants are not yet feasible,
let alone common. But were brain
transplants common, we would not think that persons should be identified just
by identifying their bodies. We would
think that, over time, it would be possible for the same body to be occupied
by different persons, and for the same person to move from one body to
another. Some might object to this, and say that were
something like a brain transplant to be possible, then it would change the
identity of the living thing, so that a body that looses one brain and gains
another should no longer be considered to be the same life. But this would be a hard line to
sustain. We do not think that liver
transplants change the identity of the living thing, and livers are more or
less the same size as brains and perform a number of functions that are
necessary for life. By parity of example, brain transplants should not
destroy the identity of the living thing either. Moreover, there is a sense in which brain
transplants do occur and occur all the time in all of us. Through the processes of nutrition and
excretion, our brains are constantly taking on new material and excreting old
material. In effect, they are being
transplanted, part by part, over time.
Yet we do not think that this changes their identity. According to Locke’s criterion for animal
body identity, it does not matter what organs are transplanted into our out
of the body, or what atoms are ingested or excreted. As long as the body continues to live
through the operation, it is that same body.
So if my brain is transplanted into your body and your brain into
mine, your body is still the same body after the operation that it was
before, as is mine. I might think that
my self is now in your body, but then I must think of my self as something
distinct and separable from my body (as I do insofar as I think that you now
have “my” body). This raises a question: Why are we inclined to suppose that our
selves have changed bodies when we have a brain transplant? If a brain transplant is no different from
a liver transplant, and I think that I would be the same self after a liver
transplant, why do I think that a brain transplant would move my self into a
different body, rather than think that I would still continue to be the same self
in the old body? The answer to this question seems to rest with
the fact that, while brains and livers both perform important life functions,
only brains perform cognitive functions.
It is through our brains that we sense, think, feel, desire, and will. In a word, it is through our brains that we
are conscious. And, as Locke pointed
out, we take our self to be wherever our consciousness is. If I suddenly start seeing the world as if
I were peering out through your eyes and feeling it by feeling what is
happening to your body, then I think that my self is in your body. This is also why, in the case mentioned
earlier of the criminal who undergoes a brain transplant in order to perform
a crime, our intuition is to charge the body that contains the criminal’s
brain with the crime, rather than the body that actually performed the
crime. For we think that it was
through the brain that the mens rea
or criminal intention and decision to perform the criminal deed was
formulated and executed. But we should not slide into thinking that we
could simply equate the brain with the person. After all, as noted earlier, the brain
itself is constantly being altered over time.
The atoms that go to make it up are constantly being excreted and
replaced with new atoms. If it is the
brain that is responsible for our consciousness, then it is not the
substances that go to make it up that make us consider ourselves the same
selves, but rather the way those substances are organized to enable the brain
to think the thoughts it does. But manner of organization, being a mode, is
something that can be transferred from one substance to another. We could imagine an operation that does not
actually transfer any substance from one body to another but merely alters
the manner in which the neurons in the brain are connected, erasing the
connections from one person’s brain and replacing them with the connections
in another person’s brain. If
consciousness is nothing other than just what is produced by the manner of
arrangement or connection of the substances in the brain, then transferring
this manner or arrangement or connection should constitute transferring
consciousness. We seem compelled, therefore, to recognize
that selves are distinct from living bodies and even from brains. But the same set of considerations that we
have just raised concerning the relation between selves and bodies also
applies to the relation between selves and minds, supposing that such things
exist. We think of minds as simple
spiritual substances. But are we
sure? Might minds be compounds of many
spiritual substances the way bodies are compounds of physical atoms? If so, then perhaps selves or persons might
be complex modes arising from the organization or functioning of compound
spiritual substances. But if that were
the case, then it might be possible for consciousness to be transferred from
one mind to another for just the same reasons that we earlier speculated that
it might be possible for consciousness to be transferred from one brain to
another. Though we do not know what makes up our selves
— whether they are simple spiritual substances, compound spiritual
substances, or somehow constituted from physical substances — we do know the
functions that these selves perform: each of us is aware of his or her own
experiences and past experiences, and whatever the self may be, wherever that
awareness is, that is where the self is. This awareness or consciousness can be used as
a criterion for personal identity. For
one of its features is that it just is “personal.” Only I can experience my thoughts and
remember my past experiences. No one
else can know what is going on in my consciousness, unless of course I choose
to tell them, or unless I engage in certain behaviours that allow others to
conjecture what I am thinking, and even then what others know is not my
thoughts, but really just my words or actions, from which they infer my
thoughts. Similarly, no one else can
remember my thoughts. The best that
they can do is remember that I said or did things, and infer from that that I
likely had certain thoughts. This is why Locke declared that the identity
of persons is determined by the extent of their consciousness. Those thoughts, sensations, desires,
volitions, and memories that I am now conscious of constitute my current
person. Any other, currently existing
thoughts, sensations, desires, volitions and memories that I am not conscious
of must constitute other persons. And
of all the past persons that existed at any given past moment in time, there
is at most one whose consciousness I may have some partial access to, via
memory, whereas no one else has the least access to that person’s
consciousness. This makes me identical
with that past person. But my thoughts, intentions, volitions, and
memories — the things that go to make up my consciousness — are really just
bits of information. Today, we think that what makes a bit of information the
same from one moment to the next is just that it continues to say the same
thing. The identity of a bit of information
has nothing to do with how it is stored or retrieved. A bit of information may be stored in a
book, on paper; in words, on magnetic tape; or in “bits” and “bytes” on a
computer disk. It is the same bit of information regardless of where it is stored
(or what substance it is stored on). In contrast to consciousness and memory, which
are bits of information, brains and souls are substances or, as we would put
it today, storage systems for bits of information. And in principle, just as information can
be deleted from one storage system, e.g., one computer hard drive, and
transferred to another, so consciousness and memory, being just a string of
bits of information, can be transferred to a different storage system — a
different brain or soul — and still be the same. They could even be copied to a number of
different thinking substances simultaneously and wiped clean from the
original thinking substance that they were imprinted on. Or a thinking substance that has had its
consciousness and memories wiped away could subsequently have them recopied,
with new information added. Locke did not know about the distinction
between hardware and software in computers or have a concept of information
that can be copied from one storage system into another. But his concepts of thought and will as
modes and minds or brains as substances did the same job for him. They led him to hold that if we are worried
about identifying the person who performed a crime, that is, the consciousness
that had the criminal act of will, then we need to worry about where the
modes (thoughts and volitions) are, not where the substances (minds or
brains) are. By this criterion, the person who performed
the crime is the one who is now consciousness of having formed the criminal intent
and willed the criminal act. And the
person who now remembers having performed that criminal act of will is the
guilty person, regardless of which soul or which body that person may now
have come to inhabit. But then, by the
same token, if that person should have been wiped out or destroyed, somehow,
then even if the body and indeed even if the soul that the person inhabited
should persist, it could not justly be held responsible for the crime. If a criminal convicted and sentenced to be
executed is shot and killed while attempting to escape custody, and the
criminal’s heart is transplanted into someone else, the justice system does
not demand that, on the date set for the execution, the heart be removed from
this other person for execution. Similarly,
if the criminal consciousness is no longer in the whole body or the whole
soul it would be equally unjust to proceed with the execution. Consider a case where a person convicted of
a crime suffers a blow to the head and loses all memories of his or her past
life. In this case we can be sure that
the body has persisted, but how can we tell whether the self or person was
not destroyed by the accident? The
only thing we have to go on as a criterion in determining the identity of
selves is their consciousness of their own past states and where that is
lacking we are in no position to claim that the self persists. This is why Locke claimed that it would be
wrong to punish sleeping Socrates for crimes that waking Socrates performed
because sleeping Socrates has no more connection with the consciousness of
waking Socrates, and so is no more the same person with waking Socrates, than
you or I are. Of course, we have no way to see into the
souls of others to determine whether they remember performing criminal
acts. This means that when attempting
to identify perpetrators of crimes we have to fall back on other, less
reliable criteria, such as having the same body or the same brain. We do this in the belief (usually true),
that souls do not get translated from one body to another, and consciousness
does not ever get fully erased. But
the importance we attach to the idea that it is necessary to identify the
consciousness that performed the criminal act of will is revealed by our
wanting to obtain confessions from criminals, even when the evidence against
them is otherwise clear, and by our reluctance to punish criminals if, for
whatever reason, they have no memory of the criminal act. Think, for example, of cases where
individuals who performed crimes while sleep-walking have been acquitted of
guilt, even though their bodies clearly performed the offense. Implications
of Locke’s position on personal identity.
Locke’s
conclusion is that what is ultimately most important to us is not identity of
substance (that is of body or soul) but identity of person. This is because it is the person who
contains the consciousness of having willed, and so the person is the moral
agent responsible for crimes and good deeds.
It is this moral agency that we are most concerned with in our
dealings with others (though identity of body is relied upon as an indication
of where the identity of person is likely, but not necessarily, to be
found). Identity of soul-substance is
actually irrelevant for determining the identity of moral or responsible
agents. For, firstly, soul-substance
cannot be perceived, whereas the identity of our own consciousness can be
perceived by ourselves, and that of others reported to us by them. And, secondly, in principle,
consciousnesses could be transferred between different souls, and since it is
the consciousness that performed and remembers the criminal or noble acts of
will, that is what we are ultimately concerned with. Indeed, even for God, who knows all and is
able to see where the same souls are from one moment to the next, same soul
and same person are different notions.
God could, if he wanted, transfer consciousnesses between souls and so
make one soul contain the memory of criminal deeds that were willed by
another soul. Locke drove a wedge between our concepts of
personality and moral agency on the one hand, and soul or thinking substance
on the other. Many people in Locke’s day were deeply committed to the notion
that we have an immortal soul. But if
Locke is right, the thing that is morally responsible for good and evil
deeds, and that is therefore deserving of reward and punishment in this life
or the next, is not the soul but the person.
And far from being immortal, the person is constituted of one of the
most ephemeral and transitory things there is: information. It is a mere modification of a substance
that can easily be wiped out even while the substance remains the same. In Locke’s day, this was perceived as a
pernicious teaching. It called the
afterlife into question and attacked the basis for morality by leading people
to doubt whether they would be punished in hell for their misdeeds. Locke’s own view on these matters was that the
inherence of our consciousness in an immortal soul can only be accepted on
faith. The person that we are consists
of a consciousness of present experiences and memories of past
experiences. Whether that
consciousness is born with the soul, stays with it throughout its life, and
is retained by the soul after death, so that the soul does not run off and
become someone else, is not something we can ever hope to know for sure. Locke speculated that the goodness of God
would not permit that a soul that never willed or committed a wicked deed be
sent to eternal damnation merely because by some accident it came to be
imprinted with some criminal’s memories.
God will ensure, Locke hoped, that the same souls will keep the same
memories, so that rewards and punishments are justly distributed. But the ties had been loosened, and
alternatives, including the alternative that persons might just die and never
be resurrected, were made more plausible and less liable to refutation. The only thing that allows us to suppose
that the alternatives are not correct is faith, not a sure and certain
knowledge of the way things must be. These were profoundly unsettling consequences
for many of Locke’s more orthodox Christian readers. ESSAY
QUESTIONS AND RESEARCH PROJECTS
1. Outline Locke’s theory
of personal identity and then comment on whether phenomenon of false memory
poses any problems for that theory. Supposing that someone can be convinced
(say by a skillful police interrogator) that they remember committing a crime
that they did not commit, would they in fact become guilty of that crime?
2. Outline Locke’s theory
of personal identity and then comment on whether the phenomenon of the
transitivity of identity poses problems for that theory. We think that identity is transitive, that
is, that if a=b and b=c then a=c. But,
to cite a case popularized by Thomas Reid, we can imagine a man who as a boy
was beaten for stealing cherries, who as a young adult seized a standard in
battle, and who as an old man is a general.
The general remembers seizing the standard, but not being beaten; the
person who seized the standard remembers being beaten. Yet Locke’s account seems to entail that
while the general is the same person as the soldier who seized the standard,
and the soldier is the same person as they boy who was beaten, the general is
not the same person as the boy.
3. According to Locke’s
theory of personal identity, a person who cannot remember having committed a
crime cannot be considered guilty of that crime, even if the person happens
to now inhabit the body that performed that crime. This claim was challenged by Molyneux, who
charged that we do take people who, say, get so drunk they cannot remember
what they are doing and who then commit crimes to be responsible for those
crimes. Locke’s correspondence with
Molyneux on this question is discussed by Henry Allison, “Locke’s Theory of
Personal Identity,” in Ian Tipton, ed., Locke
on human understanding (Oxford: Oxford University Press, 1977), P. Helm,
“Did Locke Capitulate to Molyneux?” Journal
of the history of ideas 42 (1981): 469-477, and Henry Allison and
Nicholas Jolley, “Locke’s Pyrrhic Victory,” Journal of the history of ideas 42 (1981): 672-74. Survey this literature and comment on what
it establishes.
4. Survey the recent
philosophical literature on identity and personal identity. Have recent philosophers improved
significantly on Locke’s account and if so how? |