## 1. Locke on Persons and Personal Identity: The Basics



Locke's most thorough discussion of the persistence (or
diachronic identity) of persons can be found in Book 2, Chapter 27 of
the *Essay* ("Of Identity and Diversity"), though
Locke anticipates this discussion as early as Book 1, Chapter 4,
Section 5, and Locke refers to persons in other texts, including the
*Second Treatise of Government*. The discussion of persons and
their persistence conditions also features prominently in
Locke's lengthy exchange with Edward Stillingfleet, Bishop of
Worcester (1697-1699).



Locke begins "Of Identity and Diversity" by first getting
clear on the principle of individuation, and by setting out what some
have called the place-time-kind principle--which stipulates that
no two things of the same kind can be in the same place at the same
time, and no individual can be in two different places at the same
time (L-N
 2.27.1).[2]
 With some of the basics of identity in place, Locke posits that
before we can determine the persistence conditions for atoms, masses
of matter, plants, animals, men, or persons, we must first know what
we mean by these terms. In other words, before we can determine what
makes atoms, masses of matter, plants, animals, men, or persons the
same over time, we must pin down the nominal essences--or general
ideas--for these kinds. Of this Locke says, 



> 
> 
> 'Tis not therefore Unity of Substance that comprehends all sorts
> of *Identity*, or will determine it in every Case: But to
> conceive, and judge of it aright, we must consider what *Idea*
> the Word it is applied to stands for.... (L-N 2.27.7)
> 
> 
> 



That we must define a kind term before determining the persistence
conditions for that kind is underscored in Locke's definition of
"person". Locke starts off by saying, 



> 
> 
> This being premised to find wherein *personal Identity*
> consists, we must consider what *Person* stands for....
> 
> 
> 
> 



He goes on, 



> 
> 
> which, I think, is a thinking intelligent Being, that has reason and
> reflection, and can consider it self as itself, the same thinking
> thing in different times and places.... (L-N 2.27.9) 
> 
> 
> 



A person for Locke is thus the kind of entity that can think self
reflectively, and think of itself as persisting over time. 



Locke additionally asserts that persons are agents. For Locke
"person" is a 



> 
> 
> ...Forensick Term appropriating Actions and their Merit; and so
> belongs only to intelligent Agents capable of a Law, and Happiness and
> Misery. (L-N 2.27.26) 
> 
> 
> 



Persons are therefore not just thinking intelligent beings that can
reason and reflect, and consider themselves as the same thinking
things in different times and places, but also entities that can be
held accountable for their actions. It is *because* persons can
think of themselves as persisting over time that they can, and do,
plan ahead, with an eye toward the punishment or reward that may
follow.



Just after Locke defines "person", he begins to elucidate
what makes any person the same person over time. He asserts that 



> 
> 
> ...consciousness always accompanies thinking, and 'tis
> that, that makes every one to be, what he calls *self*. (L-N
> 2.27.9) 
> 
> 
> 



Consciousness is what distinguishes selves, and thus, 



> 
> 
> ...in this alone consists *personal Identity, i.e.* the
> sameness of rational Being: And as far as this consciousness can be
> extended backwards to any past Action or Thought, so far reaches the
> Identity of that *Person*; it is the same *self* now it
> was then; and 'tis by the same *self* with this present
> one that now reflects on it, that that Action was done. (L-N 2.27.9)
> 
> 
> 
> 



After the initial assertion that the diachronic identity of persons
consists in sameness of consciousness, Locke goes on to use various
imaginary cases to drive this point home.



The imaginary cases that Locke employs are not dissimilar to ancient
cases, such as the Ship of Theseus, reported by Plutarch. In this
case, we are asked to imagine a ship that has slowly had its planks
replaced with new ones. The intuition Plutarch's case is
intended to test is whether, at the end (when the ship has an entirely
new material constitution), we have the same ship as before. Likewise,
Locke is using cases to test readers' intuitions about
persistence and identity. But it is arguable that Locke is the first
to devise such cases to specifically test readers' intuitions
about *persons* and the conditions under which they are the
same. Locke is thus carving out a new conceptual space through such
imaginary cases. A few of these will be outlined and discussed in what
follows. 



In the "prince and the cobbler" passage, or L-N 2.27.15,
Locke asks the reader to imagine the soul of a prince entering and
informing the body of a cobbler, taking all of its "princely
thoughts" with it. In this scenario, the person called
"prince" ends up persisting in the man identified as the
"cobbler", because the prince's consciousness goes
along with the prince's soul. Just after Locke describes this
scenario, he says, 



> 
> 
> I know that in the ordinary way of speaking, the same Person, and the
> same Man, stand for one and the same thing. And indeed every one will
> always have a liberty to speak, as he pleases, and to apply what
> articulate Sounds to what *Ideas* he thinks fit, and change
> them as often as he pleases. But yet when we will enquire, what makes
> the same *Spirit, Man*, or *Person*, in our Minds; and
> having resolved with our selves what we mean by them, it will not be
> hard to determine, in either of them, or the like, when it is the
> *same*, and when not. (L-N 2.27.15)
> 
> 
> 



Through the "prince and the cobbler" passage it not only
becomes clear that a person goes where their consciousness goes, but
also that Locke distinguishes between the term "man"
(which is synonymous with "human being") and
"person".



Other scenarios that Locke conjures, such as the "waking and
sleeping Socrates" case (L-N 2.27.19), make clear that even if
an individual remains the same man, he may not persist as the same
person. Here Locke says,



> 
> 
> If the same *Socrates* waking and sleeping do not partake of
> the same *consciousness*, *Socrates* waking and sleeping
> is not the same Person. And to punish *Socrates* waking, for
> what sleeping *Socrates* thought, and waking *Socrates*
> was never conscious of, would be no more of Right, than to punish one
> Twin for what his Brother-Twin did, whereof he knew nothing, because
> their outsides were so like, that they could not be distinguished; for
> such Twins have been seen. (L-N 2.27.19)
> 
> 
> 



If Socrates has a different consciousness by day than he does by
night, then waking Socrates ought not be punished for what sleeping
Socrates does. This is because although Socrates is the same man by
day as he is by night, he is a different person by day than he is at
night (and moral responsibility lies with persons, according to
Locke). Thus while the identity of consciousness determines the
identity of person, the identity of persons and the identity of men
come apart for Locke--or at least they
 *can*.[3]




Locke additionally distinguishes between persons and souls. There is
evidence for this in L-N 2.27.13. Here Locke claims, 



> 
> 
> But yet to return to the Question before us, it must be allowed, That
> if the same consciousness ... can be transferr'd from one
> thinking Substance to another, it will be possible, that two thinking
> Substances may make but one Person. 
> 
> 
> 



If consciousness can actually be transferred from one soul to another,
then a person can persist, despite a change in the soul to which her
consciousness is annexed. Thus if a reader's soul switches out
as she progresses from the start of L-N 2.27 to the end, so long as
the reader's consciousness remains the same, she remains the
same person, according to Locke.



On top of this, Locke asserts that even if an individual has the same
soul, he may fail to be the same person. Locke makes this point in L-N
2.27.14, 23, and 24. In the "day and night-man" passage,
or 2.27.23, Locke asks the reader to imagine "...two
distinct incommunicable consciousnesses acting the same Body, the one
constantly by Day, the other by Night" (L-N 2.27.23). Locke goes
on to suggest that the "...*Day* and the
*Night-man*" are "as distinct persons as
*Socrates* and *Plato*" (L-N 2.27.23). Locke then
makes clear that this is the case even if day and night-man share the
same soul:



> 
> 
> For granting that the thinking Substance in Man must be necessarily
> suppos'd immaterial, 'tis evident, that immaterial
> thinking thing may sometimes part with its past consciousness, and be
> restored to it again, as appears in the forgetfulness Men often have
> of their past Actions, and the Mind many times recovers the memory of
> a past consciousness, which it had lost for twenty Years together.
> Make these intervals of Memory and Forgetfulness to take their turns
> regularly by Day and Night, and you have two Persons with the same
> immaterial Spirit, as much as in the former instance two Persons with
> the same Body. So that *self* is not determined by Identity or
> Diversity of Substance...but only by identity of consciousness.
> (L-N 2.27.23) 
> 
> 
> 



Just as the "waking and sleeping Socrates" passage, L-N
2.27.23 shows that there can be a change of person due to a change in
consciousness, and this is the case even though there is no change in
man. But, what Locke also makes clear through L-N 2.27.23 is that
there can be a change of person even though there is no change in
soul. Thus while many philosophers (including Plato, Rene Descartes,
Samuel Clarke, etc.) think that one cannot be a person unless one has
an immaterial soul, and the identity of persons rests in the identity
of souls, Locke makes the bold move of pulling persons and souls
apart.



In addition to this, Locke calls the substantial nature of souls into
question. Locke takes thought to be immaterial, and while Locke
contends that the immaterial cannot be reduced to, or explained in
terms of, the material, Locke is not committed to substance dualism,
when it comes to finite thinkers. This is because Locke thinks
substratum--or the substance that underlies and supports any
particular substance's qualities--is impossible for finite
minds to penetrate. Additionally there is nothing in the concepts
"thought" and "matter" that allows us to
deduce that one excludes the other, and God could have superadded the
ability to think to formerly inert systems of matter. In Locke's
picture, we cannot know whether the substance (or substratum) that
underlies thinking and willing is different from the substance (or
substratum) that underlies being solid and white, or yellow and
malleable. Locke's official position on the substantial nature
of finite thinkers is therefore one of agnosticism.


## 2. Locke on Persons: What's Up for Debate



This section outlines some of the areas of Locke's text, and
aspects of Locke's view, that continue to be debated by
historians of philosophy working to make sense of Locke's
picture of persons and their persistence conditions today. As will
soon become clear, there is disagreement about *almost every
aspect* of Locke's discussion of persons, and even some of
what has been presented thus far betrays a particular interpretive
framework.



One of the overarching questions asked about Locke's
*Essay* is how much it includes metaphysical exploration. Some
think that Locke's project is *exclusively*
epistemological, citing (among other passages) the following as
evidence for their view: In the *Epistle to the Reader*, Locke
describes himself as an "underlabourer". Locke then goes
on to say,



> 
> 
> This, therefore being my *Purpose* to enquire into the
> Original, Certainty, and Extent of humane Knowledge; together, with
> the Grounds and Degrees of Belief, Opinion, and Assent; I shall not at
> present meddle with the Physical Consideration of the Mind; or trouble
> my self to examine, wherein its Essence consists, or by what Motions
> of our Spirits, or Alterations of our Bodies, we come to have any
> Sensation by our Organs, or any *Ideas* in our Understandings;
> and whether those *Ideas* do in their Formation, any, or all of
> them, depend on Matter, or no. These are Speculations, which, however
> curious and entertaining, I shall decline, as lying out of my Way, in
> the Design I am now upon. (L-N 1.1.2) 
> 
> 
> 



Under this reading, Locke is interested in determining what we can and
cannot know by first determining how we come to have ideas, but what
this entails is determining which activities give rise to our ideas,
rather than investigating the metaphysical nature of the thinking
thing wherein these activities--sensation and
reflection--take place. Likewise all other explorations within
the *Essay* eschew metaphysics.



Those who read L-N 2.27 as part of a project which is purely
epistemological see the claims that Locke makes about the persistence
of persons as claims about *what we can know* about the
persistence of persons. As Lex Newman puts it, 



> 
> 
> Locke's broader aim is to clarify the conditions under which we
> *judge* that we are numerically the same with some earlier
> person, not the conditions under which we strictly *are* the
> same person. (2015: 90) 
> 
> 
> 



Under this kind of reading, Locke's claim that the identity of
any person does not rest in the identity of substance (L-N 2.27.10 and
23) amounts to the claim that if any person wants to determine whether
they are the same, they do not look to substance to find out. The idea
is that because we have such an impoverished notion of substance in
general, we do not look to substratum to determine if we are the same
person over time in Locke's view.



Other scholars tend to think that although Locke sets his task in the
*Essay* as an epistemological one, he cannot help but dabble in
some metaphysics along the way. What has been presented (regarding the
basics of Locke's picture of persons) in this entry thus far
falls within this interpretive camp. This is why the imaginary cases
that Locke employs in L-N 2.27 have been described as giving the
reader information about *what makes it the case* that a person
is the same at time 2 as at time 1. According to this view, what Locke
is giving us in L-N 2.27 are *inter alia* "the conditions
under which we strictly are the same person".



Nevertheless, within the interpretive camp that takes Locke to dabble
in metaphysics, there is widespread debate, both at the macro and the
micro level. To start with the macro level: Some who fall into this
camp see Locke making metaphysical claims in various passages
*throughout the text*. Such scholars thus see what Locke is
doing in L-N 2.27 as very much in keeping with moves that he makes in
other parts of the *Essay* (see Stuart 2013, for example).
However, others see L-N 2.27--and the metaphysics Locke is doing
therein--as a *significant break* from the methodology
that Locke employs in the rest of the *Essay*. This is because
just after Locke claims that his project in the *Essay* is an
epistemological one (1.1.2), he makes clear that in this project, he
is using the historical plain method, or roughly, the Baconian method
of induction (see Nuovo forthcoming). Of this, Locke says,



> 
> 
> ...I shall imagine I have not wholly misimploy'd my self in
> the Thoughts I shall have on this Occasion, if, in this Historical,
> plain Method, I can give any Account of the Ways , whereby our
> Understandings come to attain those Notions of Things we have, and can
> set down any Measures of the Certainty of our Knowledge, or the
> Grounds of those perswasions, which are to be found amongst Men, so
> various, different, and wholly contradictory.... (L-N 1.1.2) 
> 
> 
> 



Those who see a tension between Locke's discussion of personal
identity and the rest of the *Essay* contend that the way in
which Locke proceeds in L-N 2.27 not only includes metaphysics, but
also a reliance on thought experiments for data. Thus, rather than
surveying a number of instances, and drawing inferences from
there--or utilizing the historical, plain method--as he
claims to be doing throughout the *Essay*, Locke is doing
something quite different in 2.27: He is employing imaginary cases
instead (see Antonia LoLordo 2012, for example).



However, what the historical plain method amounts to for Locke, and
whether Locke's use of thought experiments in L-N 2.27 is in
tension with this method is also the subject of debate. So too is
whether Locke uses thought experiments in 2.27 *alone*.
Additionally, some have questioned whether the exercises that Locke
walks readers through in 2.27 count as thought experiments at all (see
Kathryn Tabb 2018, for more on this). There are thus wide-ranging
debates about how to best describe 2.27 and the methodologies Locke
employs therein. There is also much disagreement regarding how to
square these methodologies with the general description Locke gives of
his project in the *Essay*. Moreover, this is the case even
amongst those who are in agreement that Locke *is doing
metaphysics* in 2.27.



On top of this, there are deep and long-standing micro-level debates
amongst those who think Locke is giving us some metaphysics in L-N
2.27. One such debate regards the implications of Locke's
assertion that the identity of any person does not rest in the
identity of substance (2.27.10 and 23). Some scholars take
Locke's assertion that the identity of any person does not rest
in the identity of substance, and other similar claims, to be evidence
that Locke is a relativist about identity (see Stuart 2013, for
example). To get a sense of what this entails, it is helpful to
consider the contrast case: strict identity. If a philosopher holds a
strict identity theory, then she takes it that we can ask, "Is
*y* at time 2 the same as *x* at time 1?" and arrive
at a determinate answer. On the other hand, if a philosopher is a
relativist about identity, then she asserts that in response to the
former question, we have to ask "Same what?" So if we ask,
"Is Socrates the same?" a relativist about identity thinks
we have to specify under which sortal term we are considering
Socrates. Are we thinking about Socrates as a human being, or a body,
or a soul (or something else altogether)?



On top of this, the relativist about identity thinks that an entity
who is of two sorts can persist according to one, while failing to
persist according to the other. We might say that from one day to the
next, Socrates persists as the same human being, but not as the same
body. Thus when Locke says that a person can persist despite a change
in substance, or a person can persist despite a change in soul, some
scholars take Locke to be showing that he is a relativist about
identity. Relative identity readings were rather unpopular for some
time, but have experienced a resurgence as of late (see Stuart
2013).



Still, some think that attributing this kind of reading to Locke is
anachronistic. Others take issue with the fact that under a relative
identity reading, there is, properly speaking, just one entity
described under different sorts. (What we call "Socrates"
does not pick out a human being, and person, with a body and soul, but
rather one thing, described in these different ways.) This is
appealing for some, especially those who think that this is the only
way to save Locke from violating the place-time-kind principle, which
stipulates that no two things of the same kind can be in the same
place at the same time. But it lacks appeal for those who take Locke
to be claiming that persons and the human beings who house them (for
instance) are
 distinct.[4]



Some scholars take Locke's assertion that the identity of
substance is neither required nor enough for the persistence of any
person to be evidence that persons are modes (or attributes), rather
than substances (or things themselves). Such scholars then turn to
Locke's place-time-kind principle, for further evidence for
their view. They take Locke's assertion that no two things of
the same kind can be in the same place at the same time to mean that
no two *substances* of the same kind can be in the same place
at the same time. Souls are thinking substances for Locke, and if
persons are substances, they would count as such. Thus, persons cannot
be substances, for otherwise wherever there is a person and her soul
there are two thinking substances in the same place at the same time.
Those who offer mode readings additionally turn to Locke's claim
that person is a "forensic term" and Locke's bold
assertion that a demonstrative science of morality is possible as
evidence that the term "person" must be a mode term,
rather than a substance term. This line of interpretation is popular
today (see LoLordo 2012, Mattern 1980, Uzgalis 1990), but dates back
to Edmund Law (1769).



Other Locke scholars defend substance readings of Locke on persons.
They turn to Locke's claims about substance, power, and agency,
to conclude that if an entity has any power whatsoever it has to be a
substance. Persons have powers. Thus, persons have to be substances
for Locke (for arguments along these lines, see Gordon-Roth 2015,
Rickless 2015, Chappell 1990). They then have to explain what Locke
means when he asserts that the identity of any person does not rest in
the identity of substance. Those who do not take the relative identity
path usually end up working to get clear on what Locke could mean by
"substance" when he makes this claim. Many conclude that
what Locke means is that the identity of any person does not depend
upon the identity of the simple substances that compose or constitute
her. There are numerous defenders of this position today (see Alston
and Bennett 1988, Bolton 1994, Chappell 1990, and Uzgalis 1990). Thus
questions about two of the most basic features of Locke's
picture of personal identity--What is Locke's (general)
view on identity?; and, What kind of entity is a person,
exactly?--are the subject of ongoing
 debate.[5]



So too are the most clearly stated aspects of Locke's view: the
claim that persons have consciousnesses, and the accompanying
assertion that sameness of person rests in sameness of consciousness.
What is consciousness for Locke? What does Locke mean by
"sameness of consciousness"? Answering these questions
turns out to be difficult, since Locke does not say much about what he
takes consciousness to be (and we only know the persistence conditions
of any entity, once we get clear on the nominal essence of that
entity's kind, according to Locke). Nevertheless, answering
these questions is crucial to understanding Locke's theory of
personal identity since it is consciousness centered.



Some scholars take Locke to be a strict memory theorist. In other
words, consciousness just is memory for Locke. As will become clear
below, this reading dates back at least as far as Thomas Reid. Of
course, it is the case that the way a person extends their
consciousness backward is via memory. It thus may seem as if the
identity of consciousness consists in memory, or that to have the same
consciousness as she who did *x*, one has to have a memory of
doing *x*, under Locke's view. Nevertheless, as Margaret
Atherton points out, Locke talks at length about forgetfulness, and if
consciousness just is memory, then we cannot make sense of
consciousness at any given moment where a person is *not*
invoking memory (1983: 277-278). Atherton then goes on to
develop an account of consciousness that is analogous with
Locke's conception of animal "life".



The identity of consciousness is what allows for the persistence of
any person, just as the identity of life is what allows for the
persistence of any animal. "If we look at Locke in this
fashion", Atherton argues, 



> 
> 
> then what he is saying is that what makes me different at this moment
> from any other person is that *my* thoughts are identical with
> *my* consciousness of them. No one else can have my
> consciousness any more than any organism can have my life. (Atherton
> 1983: 283) 
> 
> 
> 



A person, in Atherton's reading of Locke, is a single center of
consciousness, and so long as that single center of consciousness
persists, the person persists.



Other scholars hold what is called an "appropriation
reading" (see Winkler 1991, Thiel 2011, LoLordo 2012). Under
this reading, what Locke means when he says that sameness of person
consists in sameness of consciousness, is that any person extends back
only to those mental events or acts which they *take to be their
own*. In other words, the persistence of any person or self is
best seen in terms of the "subjective constitution of the
self" (Winkler 1991: 204). There might be a worry that under
this kind of reading, Locke gives persons too much authority. That is,
a person could deny that she is the one who committed the crime, just
because she doesn't see that act as her own. But, although the
"self has a certain authority over its own constitution",
Kenneth Winkler makes clear that 



> 
> 
> it is important to realize that this authority is not consciously
> exerted. I do not willfully disown one act and appropriate another;
> instead I accept what my consciousness reveals to me. There is also a
> severe limit on that authority, imposed by the transitivity of
> identity, 
> 
> 
> 



which comes through, as Winkler notes, in Reid's
objection--an objection which Winkler thinks sympathetic readers
of Locke can answer and which is discussed in section 3 below (Winkler
1991: 206).



From these treatments it is still difficult to discern what
consciousness *is* for Locke, however. Shelley Weinberg works
to give a robust picture of Locke's conception of consciousness
in her recent book (2016). According to Weinberg, Locke uses the term
"consciousness" in two different ways: 



> 
> 
> ...Locke seems to see consciousness as (1) *a mental state
> inseparable from an act of perception by means of which we are aware
> of ourselves as perceiving*, and (2) *the ongoing self we are
> aware of in these conscious states*. (Weinberg 2016: 153) 
> 
> 
> 



The former is a momentary psychological state that allows for what
Weinberg calls 



> 
> 
> a momentary subjective experience that the self presently perceiving
> is the same as the self that remembers having once had a past thought
> or action 
> 
> 
> 



and captures the first-person experience of persisting over time
(Weinberg 2016: 153). The latter is an "objective fact of an
ongoing consciousness" (Weinberg 2016: 153). This sense of
consciousness is available from a third personal point of view, and
fills in the gaps that any person's subjective experience might
entail.



Thus, Weinberg contends that the identity, or continued existence, of
consciousness consists in a metaphysical fact, rather than
appropriation. Nevertheless, Weinberg additionally argues that the
first personal (conscious) experience of our own mental states,
whether those states are occurrent sensations, reflections, or via
remembering is a necessary, but not sufficient, condition of personal
identity. In other words, to have the awareness (or knowledge) of an
ongoing self--or (2)--we must have (1). Although there is a
range of interpretations of Locke on consciousness on the table,
Weinberg's book, *Consciousness in Locke*, marks the
first large-scale treatment of Locke's views on
 consciousness.[6]



In addition to the debate over what consciousness is, and what Locke
means when he says that the identity of any person consists in the
identity of consciousness, there is ongoing debate about what
Locke's stance is when it comes to what can *give rise*
to consciousness. That is, there is ongoing discussion of what Locke
means when he says that God could have superadded thinking to formerly
inert systems of matter, and what Locke's *actual*
position is on the substantial nature of finite thinkers. There are
those who take Locke to be truly agnostic. Those who take this line of
interpretation remind readers of Locke's stated aims at the
start of the *Essay* (as quoted earlier), and the epistemic
modesty that Locke maintains throughout the text. But, there are
others who think that Locke overstates the probability that souls are
immaterial substances, so as not to ruffle the feathers of
Stillingfleet and other religious authorities. Some in the latter
group think that Locke leans toward materialism. This raises questions
about how far Anthony Collins (discussed below) departs from the
Lockean picture, or the degree to which Locke anticipates later
materialist pictures of
 persons.[7]
 At the very least, it can be said that Locke challenges the
importance that many philosophers place on the immaterial soul to
personhood and personal
 identity.[8]
 As might be expected, this was met with mixed reviews.


## 3. The Early Modern Reception of Locke's Picture of Persons



This section addresses how Locke's view was received by his
contemporaries and by those writing in the remainder of the early
modern period (16th-18th centuries). A good
number of philosophers vehemently objected to Locke's treatment
of persons, though some defended it, and many others used it as an
inspiration, or springboard, for their own views.



Many who objected to Locke's treatment of persons did so because
they objected to the decreased importance Locke places on the soul for
personhood and personal persistence (see Joseph Butler, Thomas Reid,
and Samuel Clarke, for example). Many such philosophers argue that
numerical identity consists in no change *at all*, and the only
kind of entity that allows for identity in this strict sense is an
immaterial substance. 



Along the way, some charged Locke's theory of personal identity
with circularity. As Joseph Butler puts it, 



> 
> 
> ...[O]ne should really think it self-evident that consciousness
> of personal identity presupposes, and therefore cannot constitute,
> personal identity; any more than knowledge, in any other case, can
> constitute truth, which it presupposes. (1736 [1842: 298]) 
> 
> 
> 



Butler then asserts that Locke's misstep stems from his
methodology. He says, 



> 
> 
> This wonderful mistake may possibly have arisen from hence; that to be
> endued with consciousness is inseparable from the idea of a person, or
> intelligent being. For this might be expressed inaccurately thus, that
> consciousness makes personality: and from hence it might be concluded
> to make personal identity. (1736 [1842: 298]) 
> 
> 
> 



One of the points that Locke emphasizes--that persistence
conditions are determined via defining kind terms--is what,
according to Butler, leads Locke astray.



Butler additionally makes the point that memory is not required for
personal persistence. He says, 



> 
> 
> But though present consciousness of what we at present do and feel is
> necessary to our being the persons we now are; yet present
> consciousness of past actions or feelings is not necessary to our
> being the same persons who performed those actions, or had those
> feelings. (1736 [1842: 298]) 
> 
> 
> 



This is a point that others develop when they assert that
Locke's view results in contradiction.



The most popular, or well known, version of this line of objection
comes from Thomas Reid (1785). In the "brave officer"
objection, Reid poses the following challenge to Locke's theory
of personal identity. He says:



> 
> 
> Suppose a brave officer to have been flogged when a boy at school for
> robbing an orchard, to have taken a standard from the enemy in his
> first campaign, and to have been made a general in advanced life;
> suppose, also, which must be admitted to be possible, that, when he
> took the standard, he was conscious of his having been flogged at
> school, and that, when made a general, he was conscious of his taking
> the standard, but had absolutely lost the consciousness of his
> flogging. These things being supposed, it follows, from Mr.
> Locke's doctrine, that he who was flogged at school is the same
> person who took the standard, and that he who took the standard is the
> same person who was made a general. Whence it follows, if there be any
> truth in logic, that the general is the same person with him who was
> flogged at school. But the general's consciousness does not
> reach so far back as his flogging; therefore, according to Mr.
> Locke's doctrine, he is not the person who was flogged.
> Therefore, the general is, and at the same time is not, the same
> person with him who was flogged at school. (Reid 1785 [1851:
> 248-249]) 
> 
> 
> 



In this exercise (and other similar versions of it) we are supposed to
assume Locke's theory of personal identity, and maintain that
sameness of person consists in sameness of consciousness. When we do,
Reid expects we will conclude that the general (C) is the same person
as he who took the standard from the enemy (B) because the general (C)
remembers doing so. Additionally he who took the standard from the
enemy (B) is the same person as he who was flogged at school for
robbing the orchard (A) because he (B) remembers that past traumatic
experience. Thus C (he who is was made general) is identical to B (he
who took the standard) and B (he who took the standard) is identical
to A (he who was flogged at school).



Given the law of transitivity (which says that if C is identical to B
and B is identical to A, then C is identical to A), we should conclude
that C (the general) is identical to A (the flogged school boy). But,
since we are assuming Locke's theory of personal identity, Reid
thinks we cannot come to this conclusion. If we assume Locke's
view, Reid contends that we have to conclude that C (the general) is
not identical to A (the school boy). This is because C (the general)
has no consciousness or memory of having been flogged at school
(A).



This and other similar objections are meant to show that if we place
the identity of persons in the identity of consciousness, as Locke
suggests, then we run into a problem--namely one of
contradiction--for we get the result that C and A both are, and
are not, identical. Nevertheless, as is made clear above, there is
debate about whether Locke's claims about identity of
consciousness should be read in terms of memory, and whether Reid is
correct to take "memory" and "consciousness"
as synonymous terms for Locke.



Circularity and contradiction are just two of the major objections
launched at Locke's theory of personal identity shortly after it
is published. Importantly, these are objections to which sympathetic
readers of Locke are still responding (see Atherton 1983, Weinberg
2016, LoLordo 2012, Thiel 2011, Garrett 2003, Schechtman 2014, etc).
This gives the reader a glimpse of some of the lines of attack that
were launched against Locke's discussion of persons during the
early modern period. Nevertheless, not all of Locke's peers
attacked his picture of persons, and numerous philosophers worked to
defend his view.



One such philosopher is Catharine Trotter Cockburn. Cockburn pens her
*Defence of Mr. Locke's Essay of Human Understanding* in
 1702.[9]
 In this text, Cockburn is responding to three pamphlets directed at
Locke's
 *Essay*.[10]
 These pamphlets take aim at Locke's *Essay* rather
broadly, and Cockburn's *Defence* reflects this, but much
is said about Locke on persons and their persistence conditions
therein. Specifically, these pamphlets charge Locke with not proving
that the soul is immortal, or threatening proofs of the immortality of
the soul. They additionally charge that Locke's view leaves us
with the strange consequence that our souls are in constant flux,
making it the case that we "awake with new souls each
morning". Given the importance of the soul, its persistence, and
its immortality, to many traditional theories of personal identity,
these objections are arguably intended to be objections to
Locke's picture of persons. Cockburn is quick to defend Locke,
but proceeds carefully and thoroughly as she does so.



Cockburn points out that Locke never sets out to prove the soul
immortal, and Locke actually claims that it is *more probable*
that the soul is immaterial, than material. Moreover, even if Locke is
not committed to the soul being immaterial, this ought not threaten
proofs of the immortality of the soul. This is because what allows
Locke to speculate that God could have superadded thinking to formerly
inert systems of matter is that God is omnipotent, and surely an
omnipotent being could make souls immortal even if they are material.
Moreover, proofs for the immortality of the soul that rely on the
immateriality of the soul are not likely to convince laymen of the
soul's immortality, and may actually leave them sceptical about
whether the soul is indeed immortal (even if it is immaterial). 



Cockburn additionally attacks the assertion that Locke's claim
that "men think not always" threatens proofs of the
immortality of the soul. Of this she says,



> 
> 
> But let it be granted, that it is ever so clearly proved, that
> thinking is necessary to the soul's existence, that can no more
> prove, that it shall always exist, than it proves, that it has always
> existed; it being as possible for that omnipotence, which from nothing
> gave the soul a *being*, to deprive it of that *being*
> in the midst of its most vigorous reflections, as in an utter
> suspension of all thought. If then this proposition, *that the soul
> always thinks*, does not prove, that it is immortal, the contrary
> supposition takes not away any proof of it; for it is no less easy to
> conceive, that a being, which has the power of thinking with some
> intervals of cessation from thought, that has existed here for some
> time in a capacity of happiness or misery, may be continued in, or
> restored to the same state, in a future life, than that a
> *Being* which always thinks, may be continued in the same
> state. (Cockburn, in Sheridan (ed) 2006: 53) 
> 
> 
> 



As Cockburn points out, the notion that the soul is always thinking is
not used as evidence for the soul's immortality. Locke's
claim to the contrary thus ought not count as evidence against it, and
we ought to have faith that an omnipotent God will ensure the
soul's immortality (whether it always thinks or not).
Additionally, there is ample evidence that Locke thinks the soul is
immortal, and that persons will go on to receive divine punishment and
reward in the next life for their deeds in this life. This comes
through not just in L-N 2.27 of the *Essay*, but also in
Locke's correspondence with Stillingfleet, and many of
Locke's religious writings, including the posthumously published
"*Resurrectio et quae secuuntur*" (though Cockburn
would not have had access to the latter while drafting her
 *Defence*).[11]



Finally, Cockburn argues that the assumption that Locke's view
entails that we "awake with new souls each morning" rests
on a misunderstanding. Just as a body that was in motion and comes to
rest does not become a new body once it starts moving again, a soul
that was thinking and ceases to think does not become a new soul once
thought is restored to it. Thus, Locke's claim that we do not
always think--and indeed may have dreamless sleep--does not
have the absurd consequences for the persistence of persons that the
pamphlets charge. To this it might also be added that even if we awake
with new souls each morning, it need not mean that we are new persons
each morning, according to Locke.



Through the *Defence*, Cockburn additionally makes clear that
although Locke's theory of personal identity allows for sci-fi
switches such as those described in the "prince and the
cobbler" passage (L-N 2.27.15), the "waking and sleeping
Socrates" passage (2.27.19), and the "day and
night-man" passage (2.27.23), Locke does not think that this is
the way things *ordinarily* go. In other words, in
Locke's view it is not that persons are switching bodies and
swapping souls on a regular basis. Rather, Locke is making clear that
we should distinguish between the concepts "man",
"body", "soul", and "person".
Moreover, the persistence of any person does not always align with the
persistence of a human being or soul, as many assume. Making this
point is the purpose of those imaginary cases.



Sixty-seven years after Cockburn's *Defence*, and
twenty-one years after the correspondence between Cockburn and Edmund
Law ends, Law drafts a *Defence* of his own. Law's
*Defence of Mr. Locke's Opinion Concerning Personal
Identity* (1769) is later included in the 1823 version of
Locke's *Works*, and in it Law offers a particular
reading of the ontological status of persons. Law defends a
consciousness-based view, and makes much of Locke's claim that
person is a "forensic term". Law moves from this point to
the conclusion that Locke thinks persons are modes (or attributes)
rather than substances (or things in themselves). He says, 



> 
> 
> Now the word *Person*, as is well observed by Mr.
> *Locke*...is properly a *forensick* term, and here
> to be used in the strickt forensick sense, denoting some such quality
> or modification in man as denominates him a moral agent, or an
> *accountable* creature; renders him the proper subject of
> *Laws*, and a true object of Rewards or Punishments. (1823:
> 1-2) 
> 
> 
> 



This is significant since whether Lockean persons are best thought of
as substances, modes, or relations is something that is still debated
amongst Locke scholars today.



While some philosophers were happy to defend Locke, as Cockburn and
Law did, numerous philosophers writing in the eighteenth century
utilized Locke's theory of personal identity as a stepping stone
to establish their own even more provocative views on persons. The
ways in which these theorists go beyond Locke varies. Some of these
are outlined
 below.[12]



In Anthony Collins's correspondence with Samuel Clarke
(1707-1708), it can often look as if Collins is a mere defender
of Locke's view. Collins holds a consciousness-based view of
personal identity, and Collins invokes Locke's discussion of
persons and their persistence conditions throughout this lengthy
exchange. Nevertheless, Collins takes Locke's assertion that for
all we know God could have superadded the ability to think to formerly
inert systems of matter, and runs with it. As Larry Jorgensen puts
it,



> 
> 
> A significant difference between Collins and Locke...is that
> Collins thought that material systems provided a better explanatory
> basis for consciousness, which changes the probability calculus.
> Collins provides evidence that casts doubt on Locke's claim that
> "it is in the highest degree probable" that humans have
> immaterial souls. Although he is building from a Lockean starting
> point, namely the possibility that God might superadd thinking to
> matter, he ends up with a naturalized version: thinking "follows
> from the composition or modification of a material system"
> (Clarke and Collins 2011: 48). (Jorgensen forthcoming) 
> 
> 
> 



Collins's view on personal identity is a consciousness-based
view, but what gives rise to consciousness, according to Collins, is
likely a material system. Thus some take Locke's purported
agnosticism about the substantial nature of finite thinkers, and
proceed more forcefully in the direction of materialism. In other
words, Locke's views on the substantial nature of finite
thinkers opens the door to materialist views of persons and their
persistence conditions.



Others take criticisms launched at Locke's theory of personal
identity, including the criticism that the self (or persisting self)
is a fiction, and appear to embrace such
 consequences.[13]
 This can be seen rather readily in David Hume's *Treatise of
Human Nature* (1738). In the *Treatise*, Hume asserts that
it is not clear how we can even have an idea of the self. This is
because most take selves to be persisting entities, and all of our
ideas come from corresponding impressions. But since our impressions
constantly change, there is no one impression that can give rise to
the idea we call "self". Of this Hume says,



> 
> 
> It must be some one impression, that gives rise to every real idea.
> But self or person is not any one impression, but that to which our
> several impressions and ideas are suppos'd to have a reference.
> If any impression gives rise to the idea of self, that impression must
> continue invariably the same, thro the whole course of our lives;
> since self is suppos'd to exist after that manner. But there is
> no impression constant and invariable. Pain and pleasure, grief and
> joy, passions and sensations succeed each other, and never all exist
> at the same time. It cannot, therefore, be from any of these
> impressions, or from any other, that the idea of self is
> deriv'd; and consequently there is no such idea. (1738 Book I,
> Part IV, Section VI [1896: 251-252]) 
> 
> 
> 



Moreover, whenever Hume looks for himself, all he finds are
impressions. He says, 



> 
> 
> For my part, when I enter most intimately into what I call myself, I
> always stumble on some particular perception or other, of heat or
> cold, light or shade, love or hatred, pain or pleasure. I never catch
> *myself* at any time without a perception, and never can
> observe any thing but the perception. (1738 [1896: 252]) 
> 
> 
> 



This leads Hume to claim that we are just bundles of perceptions, in
constant flux (1738 [1896: 252]).



Thus it is not only the case that we fail to have an idea of the self,
according to Hume, but also the case that, properly speaking, no
subsisting self persists from one moment to the next. It is the
imagination that leads us astray when we think of ourselves, and other
entities, as persisting over time (1738 [1896: 254]). As Hume puts it,




> 
> 
> The identity, which we ascribe to the mind of man, is only a
> fictitious one, and of a like kind with that which we ascribe to
> vegetables and animal bodies. (1738 [1896: 259]) 
> 
> 
> 



He goes on, 



> 
> 
> It cannot, therefore, have a different origin, but must proceed from a
> like operation of the imagination upon like objects. (1738 [1896:
> 259]) 
> 
> 
> 



In moving away from a more traditional substance-based view of
personal identity (where the identity of person lies in the identity
of soul), Locke opens the door to more fragmentary treatments of
selves and
 persons.[14]




Along similar lines, some take Locke's claim that the identity
of persons lies in the identity of consciousness as fuel for the
assertion that, properly speaking, there is no special relation
between person *x* and any other future person. That is,
personal identity only exists between present and past selves, not
present and future selves. For this reason, we ought not have
prudential concern, or concern for a future self that is distinct from
our concern for others. This is the argumentative move that William
Hazlitt makes, and in *An Essay on the Principles of Human
Action* (1805), he explicitly sets as his task showing 



> 
> 
> ...that the human mind is naturally disinterested, or that it is
> naturally interested in the welfare of others in the same way, and
> from the same motives, by which we are impelled to the pursuit of our
> own interests. (1805: 1) 
> 
> 
> 



This line of argumentation is replicated and expanded almost one
hundred and eighty years later by Derek Parfit in *Reasons and
Persons* (1984), though it does not appear that Parfit is aware of
Hazlitt's view when he drafts his
 own.[15]


## 4. Locke's Lasting Impact on the Personal Identity Debate



This section briefly outlines the lasting impact that Locke has had on
the debate over persons and their persistence conditions by exploring
how Locke's theory of personal identity gets taken up in the
twentieth and twenty-first centuries. Most metaphysicians contributing
to the debate over personal identity refer to Locke's treatment
of persons in their texts. Many even *directly respond* to
Locke's view as they flesh out their own.



Most who hold psychological continuity theories of personal identity
take their views to be descendants of Locke's. This is true of
John Perry (1975), David Lewis (1976), Sydney Shoemaker (1984), and
Derek Parfit (1984), for instance (Schechtman "Memory, Identity,
and Sameness of Consciousness", forthcoming in *The Lockean
Mind*). In fact, Parfit defends what he calls a "Lockean
view" as recently as 2016 (34). What makes each of these views
*Lockean* (at least according to their authors) is that, as
Locke does, they take personal identity to consist in the continuity
of psychological life, and they take this to mean that personal
identity is relational. Moreover, like Locke, they emphasize the
forensic nature of personhood.



Marya Schechtman offers a rival interpretation to those held by Perry,
Lewis, Shoemaker, and Parfit, but Locke is very much in the foreground
of Schechtman's narrative account as well. In *The
Constitution of Selves* (1996: 15), Schechtman claims, 



> 
> 
> The argument that personal identity must be defined in psychological
> terms is first systematically presented and defended by Locke in his
> *Essay concerning Human Understanding* 
> 
> 
> 



Schechtman then goes on to show that the project of psychological
continuity theorists is "incoherent" because 



> 
> 
> [t]he goal of offering reidentification criterion is fundamentally at
> odds with the goal of defining personal identity in terms of
> psychological continuity.... (1996: 24) 
> 
> 
> 



Importantly, Schechtman does this not just by making a passing
reference to Locke and then treating Parfit, Perry, and the like, but
via a thorough examination of Locke's theory, and the objections
raised to it by Butler, Reid, and others.



Moreover, this is the case not only in Schechtman's earlier
work, but in her most recent work as well. Schechtman includes a
thirty-two page chapter titled, "Locke and the Psychological
Continuity Theorists" at the start of *Staying Alive:
Personal Identity, Practical Concerns, and the Unity of a Life*
(2014), and in "Memory, Identity, and Sameness of
Consciousness", Schechtman turns to recent developments in the
psychological study of memory to update Locke's view to
"...capture some of the crucial insights of Locke's
account, and show why it remains relevant and influential" (in
*The Lockean Mind*, forthcoming).



Those who defend animalism--or the view that persons just are
human organisms--hold a position that is quite different from
psychological continuity theories or narrative based views. Still,
most animalists respond to Locke. Some even invoke Locke's view
as they develop their own. For example, Eric Olson's animalist
view relies very heavily both on Locke's conception of
"life", and the persistence conditions Locke gives for
organisms (1997: 137-138, etc.). This is why Olson describes his
view as "Lockean".



At the same time, some animalists blame Locke for separating the
discussion of persons and personal identity from the discussion of
human beings or human animals. In *Animalism: New Essays on
Persons, Animals & Identity*, Stephen Blatti and Paul Snowdon
ask, "Why was the idea of an animal conspicuously
absent..." in the personal identity debate for so long
(2016: 3)? They go on,



> 
> 
> To answer this question, we need to return to Locke's famous
> discussion of personal identity, in which the notion of an animal was
> central...Locke exercised great care in specifying the different
> ideas for which the words 'animal' and
> 'person' stood. A reasonable conjecture, or proposal, we
> suggest, is that Locke's treatment of these two terms and
> notions was so effective that it generated in people engaging with the
> problem the conviction that the notion of a person is the central one
> fixing the type of thing the problem is about, with the consequence
> that the notion of an animal was lost to sight. (2016: 3) 
> 
> 
> 



Locke does much to distinguish between human beings (or
men)--which are animals--and persons, and Blatti and Snowdon
assert that this sets the stage for how the personal identity debate
plays out for the next several hundred years. In other words, Locke is
the reason that animalist views do not emerge until later in the
twentieth
 century.[16]



Finally, even those working to carve out an entirely new space for the
discussion of persons and their persistence conditions say something
about Locke as they proceed. Leke Adeofe outlines and develops a
tripartite picture of persons according to what he calls the
"African thought system". As he does, Adeofe aligns his
approach with Locke's. He says, 



> 
> 
> My approach, partly descriptive and partly imaginative, ought to be
> familiar; it has been borrowed from a tradition that dates back at
> least to John Locke. (2004: 69) 
> 
> 
> 



Moreover, this is the case even though Adeofe uses the African, or
Yoruba, conception of "person" to challenge Western
philosophy's treatment of persons and their persistence
conditions.



In *Real People: Personal Identity Without Thought Experiments*
(1988), Kathleen Wilkes takes aim at the proliferation of thought
experiments in the personal identity literature. It is clear that
Wilkes has the elaborate thought experiments that Parfit employs
(including teletransportation, split brain cases, etc.) in mind
throughout her critique. But, it is also clear that Wilkes traces this
methodology back to Locke. Of this she says, 



> 
> 
> The subject of personal identity...has probably exploited the
> method [of thought experiments] more than any other problem area in
> philosophy. Many of the examples are familiar:...Locke testing
> 'what we would say if' the soul of a cobbler migrated into
> the body of a prince, or if the Mayor of Queinborough awoke one day
> with all of Socrates' memories. (Wilkes 1988: 6) 
> 
> 
> 



The "prince and the cobbler" passage, or L-N 2.27.15,
proceeds in the opposite direction, with Locke asking us what we would
conclude about the soul of a prince entering and informing the body of
a cobbler, but, regardless, Wilkes takes Locke and the tradition that
follows, as her target as she works to move the discussion of personal
identity away from fantasy cases and toward real-life ones.



Locke's discussion of personal identity is central to the
current debate over persons and their persistence conditions.
Nevertheless, there are many different versions of Locke's view
that contemporary metaphysicians take themselves to be embracing or
rejecting. Even those who describe their respective views as
"Lockean"--Parfit and Olson, for instance--can
end up defending very different pictures of persons. This highlights
just how difficult it is to determine what Locke's view on
persons and their persistence conditions amounts to, despite how clear
its importance is.