## 1. Criticizing the Storehouse Model of Memory




Reid traces the target of his criticisms back to the Ancients, whom he
depicts as holding that the mind is a sensorium--a repository of
past ideas and impressions (*Essays*,
 280).[1] 
 On this
theory, perception, memory and imagination are causal processes
beginning with purely physiological events: impressions on the
brain. These physiological states are taken to have mental
correlates--sensations or ideas of sense or sense
impressions--which are the objects of perception, memory and
imagination. These ideas or impressions are representations in the
sense that they preserve, or re-present information from their
physiological correlates. According to Reid, this view recognizes no
distinction between imagination and memory. Each consists in having a
picture-like impression that remains after the object that
impressed upon the senses is gone. The only difference between the two
is in the fidelity of the imagistic impression to its cause. Memory
consists in the preservation of images imprinted in the mind from
previous experiences, while imagination consists in constructing
images that lack a duplicate in experience.




Reid offers two criticisms of the ancient theory, as he understands
it. First, the theory falls afoul of one of Reid's own
methodological strictures, namely, that a theory must adhere to
Newton's *regulae philosophandi*, or rules of
philosophizing (*Inquiry*, 12). The first rule is to posit
no merely theoretical causes and in Reid's view the second rule
forbids positing causes insufficient to explain the phenomenon in
question. According to Reid, there is no observational evidence
of the existence of impressions on the brain--they are merely
theoretical entities (*Essays*, 281). Furthermore, even if
we granted the otherwise theoretical existence of impressions, such
entities would not be sufficient to explain memory. We might
establish a correlation between impressions and memories, but it would
remain at best just that: a correlation, not a causal
explanation. Having learned Hume's lessons about causation,
Reid denies any necessary connections between impressions and memories
sufficient to regard the former as a cause of the latter. Reid
also considers whether resemblance could ground such a causal
explanation, but, having learned Berkeley's lessons about
resemblance, he denies that any mental states can resemble material
states such as impressions on the brain. Reid's second
criticism is that even if we were to grant that impressions remain
after the objects that impressed upon the senses are gone, this would
entail that we should continue to perceive objects rather than remember
them, since on the ancient theory, impressions are the immediate causes
and objects of perception (*Essays*, 282).




Though Reid identifies his target as having ancient origins, his
primary concern is with what he regards as its modern equivalent.
This modern theory was introduced by Locke and, according to Reid,
extended to its inevitable idealist and skeptical conclusions by
Berkeley and Hume. Reid excerpts passages from Locke's
*Essay Concerning Human Understanding* to illustrate the
misleading metaphors Locke inherits from the ancient
theory--metaphors of the mind as a storehouse and of ideas and
impressions as pictures.



> 
> 
> The other way of Retention is the Power to revive again in our Minds
> those *Ideas*, which after imprinting have disappeared, or have
> been as it were laid aside out of sight...This is *Memory*,
> which is as it were the Store-house of our *Ideas*...But
> our *Ideas* being nothing but actual Perceptions in the Mind,
> which cease to be any thing, when there is no perception of them, this
> *laying up* of our *Ideas* in the Repository of the
> Memory, signifies no more but this, that the Mind has a Power, in many
> cases, to revive Perceptions, which it once had, with this additional
> Perception annexed to them, that it has had them before. And in
> this Sense it is, that our *Ideas* are said to be in our
> Memories, when indeed, they are actually no where, but only there is an
> ability in the Mind, when it will, to revive them again; and as it were
> paint them anew on it self, though some with more, some with less
> difficulty; some more lively, and others more obscurely (Locke,
> *Essay*, Book II.x.1-2).




As this passage illustrates, Locke himself acknowledges that the
notion that the mind is a kind of repository or storehouse is
metaphorical. According to Locke's own theory, ideas and
impressions cannot be stored. Locke is committed to the thesis
that ideas are momentary and non-continuous and to the thesis that
identity over time requires continuous existence. These two
theses jointly entail that numerically identical ideas cannot be stored
over time. Nevertheless, Reid criticizes Locke for being unable
to extricate himself from metaphor when Locke claims that in memory,
"the mind, as it were, paints ideas anew on it self."
On what model does the mind paint the idea anew? In order to use
a previous idea as its model, the mind must remember it. But then
the ability to paint ideas anew upon itself presupposes rather than
explains memory.




Locke offers a non-metaphorical account of memory when he claims
that memory consists of two perceptions: a present perception and a
belief about that present perception, namely that one has enjoyed the
perception before. Because Locke is committed to the thesis that
numerically identical ideas cannot be stored over time, the belief must
be the belief that one has previously enjoyed a perception
qualitatively similar to the present perception, rather than
numerically identical with it. Reid criticizes this account as
circular, once more. A first-personal belief that one's
present perception is qualitatively similar to a perception one had in
the past requires remembering having had that previous perception and
recalling its quality and character. As before, Locke's
account presupposes rather than explains the phenomenon of memory
(*Essays*, 285).




Reid criticizes Hume's account of memory for duplicating
Locke's mistakes. He quotes from Hume's *Treatise
of Human Nature*:



> 
> 
> We find by experience, that when any impression has been present
> with the mind, it again makes its appearance there as an idea; and this
> it may do after two different ways: Either when in its new appearance
> it retains a considerable degree of its first vivacity, and is somewhat
> intermediate betwixt an impression and an idea; or when it entirely
> loses that vivacity, and is a perfect idea. The faculty by which
> we repeat our impressions in the first manner, is call'd the
> MEMORY, and the other the IMAGINATION (Hume, *Treatise*,
> 1.1.3.1).




Like Locke, Hume holds that ideas have no continued existence.
And so, Reid argues, Hume cannot claim that a numerically identical
idea can reappear. In addition, Hume's account faces the
same circularity objection as Locke's. Hume accounts for
memory by appealing to an idea that is qualitatively similar to, but
less forceful and vivacious than a previous idea. But the ability
to judge qualitative similarity and degrees of force and vivacity
between present ideas and past impressions presupposes memory.




Reid provides additional criticisms of Hume's account of
memory. First, Reid interprets Hume's account of memory as
committing him to the position that we have the power to repeat ideas
(though notice that Hume does not commit to this in the quoted
passage). Reid argues that this position is inconsistent with
Hume's claim that impressions are the efficient causes of
ideas. Reid's second criticism is more insightful; he
argues that differences in degrees of force and vivacity are
insufficient to sustain the distinctions between perception, memory and
imagination. Reid interprets Hume as holding that these three
faculties do not differ in kind, but rather in the degree of force and
vivacity of the ideas that are their objects. Ideas with the
greatest degree of force and vivacity are perceptions, those with a
lesser degree are memories, and those with the least degree of force
and vivacity are imaginings. Reid criticizes this taxonomy on
phenomenological grounds. Some perceptions are less forceful and
lively than some memories, as when lost in reminiscence, and some
memories are less forceful and lively than imaginings, as when lost in
reverie. Furthermore, increasing the degree of force and vivacity
does not transform a memory or an imagining into a perception.
Reid compares striking one's head against the wall to lightly
touching it to the wall. The latter has much less force and
vivacity than the former, yet lightly touching one's head to the
wall is neither a memory nor an imagining (*Essays*, 289).




Reid grants that perceptions, memories and imaginings often differ in
degree of force and vivacity, but, he argues, this difference is
insufficient to account for the special quality of presentness
represented in perceptions, the special quality of pastness
represented in memories, and the special quality of atemporality
represented in imaginings (*Inquiry*, 197). While memories may
be faint, or weak, these features are not necessary to these states
being memories, and so cannot be used to individuate them. In
addition, a present idea--whatever its degree of force and
vivacity--cannot ground judgments about events in the past
because present ideas represent events as present.



> 
> 
> For according to that theory, the immediate object of memory, as
> well as every other operation of the understanding, is an idea present
> to the mind. And, from the present existence of this idea of
> memory I am led to infer, by reasoning, that six months ago or six
> years ago, there did exist an object similar to this one...But
> what is there in the idea that can lead me to this conclusion?
> What mark does it bear of the date of its archetype?
> (*Essays*, 476)




Present ideas contain no information, qualitatively or
representationally, that could serve as the basis of judgments about
past events. As a result, no reflection on present ideas and
their quality or character is sufficient for a representation of events
in the past, as past.


## 2. A Direct Realist Theory of Memory




Contemporary philosophers and cognitive scientists recognize that
memory is a diverse phenomenon and they draw some useful distinctions
among varieties of
 memory.[2]
For example, Endel Tulving distinguishes
between episodic memory, semantic memory and procedural memory.
Remembering how to ride a bike is an example of procedural
memory. Remembering that Napoleon was defeated at Waterloo is an
example of a semantic memory. Remembering one's tenth
birthday party is an example of an episodic memory.




The distinction most relevant to the issues Reid, Locke and Hume raise
for memory and personal identity is between semantic and episodic
memory. Henri Bergson and Bertrand Russell developed a similar
distinction, and Russell's distinction between factual and personal
memory accords with that between semantic and episodic memory.
Semantic memories are properly reported using a factive
complement--a that-clause--after the verbs
'remember' or 'recall', as in 'Jane
remembers that Napoleon was defeated at Waterloo'. In
particular, a semantic memory
*cannot* be reported using the form '*S*
remembers/recalls [*x*] *f*-ing', as in 'Jane
recalls her tenth birthday party,' or 'John remembers
falling off his bike.' Only episodic memories may be
properly reported using this form. No one today can properly
report 'I remember Napoleon being defeated at Waterloo,'
though many may properly report 'I remember *that*
Napoleon was defeated at Waterloo.' On the other hand, an
episodic memory *can* be reported using the same form by which
semantic memories are reported because episodic memories may ground
semantic memories under certain circumstances. It is legitimate
to state both 'I recall my tenth birthday party,' in
reporting an episodic memory of that event and to state 'I
remember that I had a tenth birthday party', in reporting a
semantic memory, whose justification would appeal to the previous
episodic memory.




Episodic memories are further distinguished from semantic memories
by the Previous Awareness Condition on episodic memory. The
Previous Awareness Condition has been developed and examined by Sydney
Shoemaker (1970), among
 others.
Put simply, one has an episodic memory of
an event only if one was agent or witness to the event
remembered. The Previous Awareness Condition is a necessary but
insufficient condition on episodic memory. If one has an
experience as of being lost in a store as a child, but one was not in
fact lost in a store as a child, such an experience is not an episodic
memory. On the other hand, each of us has been agent or witness
to many events of which we have no episodic memory. For example,
one may not remember one's third birthday party and so lack an
episodic memory of an event to which one was surely witness.




Reid is most interested in episodic memory. Though Reid does
not use the contemporary terminology, his theory draws upon both the
distinction between episodic and semantic memory and the Previous
Awareness Condition on episodic memory. As he puts the matter:



> 
> 
> Things remembered must be things formerly perceived or known.
> I remember the transit of Venus over the sun in the year 1769. I
> must therefore have perceived it at the time it happened, otherwise I
> could not now remember it. Our first acquaintance with any object
> of thought cannot be by remembrance. Memory can only produce a
> continuance or renewal of a former acquaintance with the things
> remembered (*Essays*, 255).




Though Reid uses the term 'acquaintance,' the things
retained through memory are things previously perceived or
experienced. The term 'acquaintance' has acquired a
technical sense that it did not have in Reid's day, so it is
better to see Reid as holding that memory preserves contact with events
previously *apprehended* through perception and thereby known by
acquaintance. Acquaintance presupposes apprehension, and prior
episodes of apprehension are necessary for retained acquaintance.




According to Reid, episodic memory is not a current apprehension of a
past event, nor is it a current apprehension of a past
experience. These theoretical options were ruled out by
Reid's criticism of Locke and Hume. Rather, according to
Reid, memory is an act that preserves a past apprehension. Reid
characterizes memory as exhibiting what we now call the Previous
Awareness Condition. He holds that reports of episodic memory are
true only if the person reporting satisfies the condition, and that
experiences that otherwise *appear* to be episodic memories, but
which fail the condition, are not episodic memories (*Essays*,
264).




Reid does not count what we term 'semantic memories' as
memories in the proper sense. He discounts them not because they fail to
meet the Previous Awareness Condition, but because he holds that
semantic memories are better classified as beliefs or knowledge rather
than memories. For example, he would hold that a person today who
reports remembering *that* Napoleon was defeated at Waterloo
expresses a belief or knowledge rather than a memory. He holds
this because he requires a distinction between two sorts of beliefs
that would otherwise be obscured by the fact that each sort can be
expressed in the form of a semantic memory report. The distinction is
between beliefs that play a role in preserving past apprehension
(and which are *constituents* of episodic memory), and those
that do not play a role in preserving past apprehension (and which are
not, strictly speaking, memories). For example, Jane believes
that she dined with a friend last night. Jane has an episodic
memory of this event, and according to Reid, her belief 'that I
dined with a friend last night,' plays a role in preserving
Jane's past apprehension of dining with her friend. On the
other hand, Jane's belief that she had a third birthday party
does not play a role in preserving her past apprehension of her third
birthday party; she has no episodic memory of her third birthday
party. The difference between these two sorts of belief is
obscured by the fact that each may be expressed by using the factive
compliment: 'Jane remembers *that* she dined with a friend
last night,' and 'Jane remembers *that* she had a
third birthday party.'




According to Reid, a memory consists in a conception of a past event
and a belief about that past event, that it happened to the person who
is represented in that memory as agent or witness (*Essays*,
228, 232, 254, 257). This conception-belief structure mirrors Reid's
accounts of perception and consciousness, each of which also consist
in a conception and belief. Folescu (2018a) examines whether memorial
conception differs from or is the same as the kind of conception
ingredient in perception, consciousness, and other intentional mental
states. The belief that is a constituent of memory, on Reid's view, is
a belief of some past event, that it happened. In particular, it is a
belief that it happened to me, where the pronoun is indexed to the
person who is represented in the memory as agent or witness to the
event (*Essays*, 255, 262). The belief is *about*
or *of* the event because the other constituent of
memory--the conception--supplies the event, which is the
object of the belief. On Reid's view, the objects of memory are the
events presented in past apprehensions. Memory preserves past
apprehensions by relating us to the events originally presented in
perception--memory preserves past apprehension through conception
and belief. In particular, the objects of memory are not the past
apprehensions themselves but that which is presented in the past
apprehensions, namely, the original event (*Inquiry*,
28). Folescu (2018b) examines a tension in Reid's accounts of memory
and perception. According to Reid, we remember events that were
apprehended in the past by perception. But Reid insists that
perception is confined to the present. Because perception is confined
to the present, we cannot perceive events, which have a duration. How,
then, can we remember what we cannot have perceived? 




Reid holds that memory is not a current apprehension of an event
already presented in a past apprehension. In other words, we do
not remember events by *re-apprehending* them. Rather, the
past apprehension is itself preserved by the act of remembering the
event apprehended. Memory is an act of preservation through
conception and belief. Such preservation does not itself
constitute an *additional* apprehension over and above the
apprehension preserved. Indeed, according to Reid, it is
impossible to currently apprehend any events in the past; apprehension
is confined to perceiving present objects or being conscious of present
mental operations (*Essays*, 23, 253). Reid does not deny
that memory is itself a current mental state, nor does he deny that
memory presupposes a past apprehension. He denies only that
memory is a current apprehension, and that the object of a memory is a
past apprehension (*Essays*, 253). Memory preserves past
apprehension by conceiving of an event previously apprehended and
believing, of this event, that it happened to me.




Reid holds that memory, like perception, is immediate. Neither
the conception nor the belief that are the ingredients of memory are
formed on the basis of reasoning or testimony. Memory is an
original faculty of our constitution governed by what Reid calls
"the first principles of contingent truths." In the
case of memory, the governing principle is that "those things did
really happen which I distinctly remember" (*Essays*,
474). On Reid's view, a normally functioning human does not
and need not infer to a past event in episodic memory. In order
to infer to a past event, one must have some prior, non-inferential
relation to the event if it is to be a memory rather than a belief or
knowledge. But then this prior, non-inferential relation would be
an episodic memory. In addition, if episodic memory involved an
inference to the effect that the event happened to me, the inference
would be otiose because, as Reid claims, such a belief is already an
immediate, non-inferential component of episodic memory. In
principle, one could infer from the conception and belief that are
ingredients in memory to a further belief that the event
happened. But if such a belief plays a role in preserving past
apprehension then it is superfluous--such a belief, subject to
the Previous Awareness Condition, is already embedded in episodic
memory. If the belief does not play a role in preserving past
apprehension then it is a semantic memory, which, according to Reid, is
among the species of belief or knowledge rather memory.




The distinction between beliefs that are ingredients in episodic
memories and beliefs that are based on, but not ingredients in,
episodic memories allows Reid to account for cases in which a memorial
experience continues to represent an event as having happened, even
when the person who seems to remember the event has what she regards as
an overriding reason to believe that the event did not occur. The
belief that is an ingredient in the experience represents the event as
having happened to the person who seems to remember it. Further, the
belief will continue to represent the event as having happened to the
person, even under conditions in which she forms a separate belief, not
embedded in the memorial experience, to the effect that it did not
happen to her.




The distinction also allows Reid to satisfy a constraint on any
adequate theory of memory; namely, that it explain why memory
represents events as having the special quality of being in the
past. If belief were not an ingredient in episodic memory, then
though we might *believe* that the events we remember are in the
past, *memory* could not represent events as past. If
belief were not an ingredient in memory, then memory alone would relate
us to an event previously apprehended. But the apprehension
preserved is an apprehension of an event that was, at that time,
represented in that apprehension as present. The pastness of the
event apprehended is not part of the content of the past
apprehension. But because a belief that the event happened to me
is embedded in the memory itself, memory represents not merely past
events, but past events as having occurred. In other words, the
belief that is partly constitutive of episodic memory is tensed.




One might wonder whether Reid's account of memory is subject to the
same criticisms he levels against Locke and Hume. Does Reid appeal to
the storehouse metaphor when he claims that memory is preserved past
apprehension? Reid criticizes Locke and Hume for begging the
question. Yet by holding that memory is in part constituted by a
belief, does Reid not also assume the very phenomenon to be explained?
Reid can avoid the criticisms to which the theory of ideas is
vulnerable by insisting that memory is not a current apprehension, but
rather a preserved past apprehension. His theory of memory is a direct
realist theory because, according to Reid, memory is not directed
towards any present perceptions, ideas, or impressions--stored or
otherwise. Neither is memory directed towards any past perceptions,
ideas, or impressions--stored or otherwise. Memory is directed
towards the events presented in past apprehensions. Because
apprehensions, perceptions, ideas, and impressions are never the
objects of memory, they do not need to be stored for use by
memory. Likewise, the belief that is an ingredient in memory is not
about any present or past apprehensions. If it were, Reid's theory
would be subject to the same circularity objection he presses against
Locke and Hume.




On Reid's theory of memory, an apprehension establishes a
direct relation to an event, which relation is preserved in memory by
the acts of conceiving the event and believing of the event conceived
that it happened to the person who remembers. It is a direct
realist theory of memory because it departs from the model on which
memory is a current apprehension of a past event or a current
apprehension of a past apprehension. On the direct realist view,
memory preserves past apprehension of an event through conception and
belief. Reid's theory captures how memory, like perception,
represents the world, rather than our experiences of the world.


## 3. Objecting to Locke on Personal Identity




Reid, Locke and others are interested in the notion of episodic memory
not only for its own sake, but also because of its conceptual
connection to the notion of personal identity. If Joe remembers,
episodically, winning the World Series, then Joe must have existed at
the time of his winning the World Series. This is why the Previous
Awareness Condition characterizes episodic but not semantic
memory. Unlike Joe's memory that Napoleon was defeated at Waterloo,
his memory of winning the World Series logically entails Joe's
existence at the time of the event remembered. In other words,
episodic memory is logically sufficient for personal identity: if
*S* remembers at time *t**n*
(episodically) an event at time *t*1, then
*S* existed at time *t*1. In addition, memory
reports are often taken to be *prima facie* evidence for
statements about the past history of the person reporting.




Reid's main criticism of Locke's theory of personal identity is that
Locke moves from these truisms concerning the conceptual and
evidential relations among the notions of memory and personal identity
to a hypothesis concerning the metaphysical relations among them
(*Essays*, 277). In this, Reid follows Butler's influential
dissertation "Of Personal Identity," appended to *The
Analogy of Religion* in 1736.




Reid interprets
Locke as holding what is now called the Memory Theory of personal
identity (*Essays*, 277). On this theory, personal
identity *consists* in memory; sameness of episodic memory is
metaphysically necessary and sufficient for sameness of persons.
In other words, on the Memory Theory, what *makes* a person
identical with herself over time is her remembering or being able to
remember the events to which she was witness or agent. If she
cannot episodically remember an event, then she is not identical with
any of the persons who was witness or agent to the event. In such
a case, she would bear the same relation to that event as any other
person for whom a memory of the event could rise at best to the level
of a semantic memory. If she can episodically remember an event,
then her recollection or ability to recall that event makes her
identical with the person represented in that memory as agent or
witness to the event.




But there is a secondary, more subtle line of disagreement between
Reid and Locke. Much of Locke's chapter *Identity and
Diversity* is dedicated to establishing that the self is not a
substance, material or immaterial. By contrast, Reid holds that
the self is a simple, unanalyzable immaterial substance with active
powers. Reid argues that Locke cannot sustain both the thesis
that the self is not a substance and the thesis that self remains
identical over time. While Reid's criticisms of the Memory
Theory are more well known, his criticism of Locke's insistence
that the self is not a substance reveals two very different accounts of
the metaphysics of identity. While Locke argues that the identity
conditions for different kinds of things differ, so that the conditions
under which a mass of matter, and an animal, and a person are not the
same, Reid holds that identity is confined solely to substances that
have a continued, uninterrupted existence and which do not have
parts. In other words, according to Reid, strictly speaking the
only real identity is personal identity (*Essays*,
266-267). "The identity...we ascribe to bodies,
whether natural or artificial, is not perfect identity; it is rather
something which, for the conveniency of speech, we call identity"
(*Essays*, 266).




Reid begins his interpretation and criticism of Locke's theory
by noting that Locke defines the term 'person' as meaning
"a thinking intelligent Being, that has reason and
reflection..." (Locke *Essay*, Book
II.xxvii.9). Reid is friendly to this characterization of the
self. But, Reid notes, Locke appears to equivocate between the
notion of a person as a 'thinking Being,' and the notion of
a person as that which is preserved through consciousness and
memory. Reid paraphrases a passage from Locke's *Essay
Concerning Human Understanding*:



> 
> 
> Mr LOCKE tells us however, "that personal identity, that is, the
> sameness of a rational being, consists in consciousness alone, as, as
> far as this consciousness can be extended backwards to any past action
> or thought, so far reaches the identity of that person. So that
> whatever hath the consciousness of present and past actions, is the
> same person to whom they belong" (*Essays*
> 275-276).




The passage in Locke differs from Reid's paraphrase:



> 
> 
> ...*personal* *Identity, i.e.* the sameness of a
> 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 (Locke, *Essay*, Book
> II.xxvii.9).




Reid's first criticism rests on his interpreting Locke's
definition as committing him to the position that a person is a subject
of thought, which Reid regards as implying that a person is a thinking
substance. At the same time, Locke appears to be committed to an
analysis of personal identity in terms of memory, or, as Locke would
put it, consciousness of the past. Reid notes that Locke is aware
of some of the consequences of the Memory Theory: if sameness of
consciousness or memory is necessary and sufficient for sameness of
person, then it is possible for there to be sameness of person without
sameness of thinking Being. In other words, it is logically and
metaphysically possible for a person to be "transferred from one
intelligent being to another," or for "two or twenty
intelligent beings to be the same person" (*Essays*,
276). Locke's response to these worries, as well as worries
about periods of interrupted consciousness, as in sleep, highlights
Reid's criticism: "...[I]n all these
cases...doubts are raised whether we are the same thinking thing;
*i.e.* the same substance or no. Which however reasonable,
or unreasonable, concerns not *personal Identity* at all.
The Question being what makes the same *Person*, and not whether
it be the same Identical Substance..." (Locke,
*Essay*, Book II.xxvii.10). Reid's criticism is not
that cases of transfer or fission are incoherent, though he thinks they
are. Rather, his criticism is that the possibility of sameness of
person without sameness of thinking Being that the Memory Theory allows is
inconsistent with Locke's characterization of *a person* as a
'thinking Being'. Given that Reid thinks that this
initial characterization is correct, he regards this as a
*reductio* of the Memory Theory.




Reid's second criticism is his most famous and is often
referred to as the case of the Brave Officer:



> 
> 
> 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. When 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 as him who was
> flogged at school (*Essays*, 276).




According to the Memory Theory, personal identity *consists* in
memory; that is, sameness of memory is metaphysically necessary and
sufficient for sameness of person. On this account, given that
sameness of memory is sufficient for sameness of person, if a person
at time *t**n* remembers (episodically) an
event that occurred at time *t*1 then the person at
time *t**n* is identical with the person who
was witness or agent to the event at time *t*1. If
the brave officer who has just taken the flag of the enemy remembers
being beaten at school, then the brave officer is identical with the
boy who was beaten. So too, if the general remembers taking the
enemy's flag, then the general is identical with the brave officer. If
the general is identical with the brave officer, and the brave officer
is identical with the boy, then by the transitivity of identity, the
general is identical with the boy.




However, on this account, given that sameness of memory is a necessary
condition for sameness of person, if a person at time
*t**n* does not remember (episodically) an
event that occurred at time *t*1, then the person at
time *t**n* cannot be identical with any
person who was witness or agent to the event at time
*t*1. If the general cannot remember being beaten at
school, he cannot be identical with the boy who was beaten. Thus, the
Memory Theory is committed to mutually incompatible theses: that the
General is identical with the boy and that he is not.




Reid's third criticism is terminological: he argues that Locke
confounds consciousness with memory--elsewhere Reid also argues
that Locke confounds consciousness with reflection (*Essays*,
58). Consciousness and memory are distinct phenomena, according
to Reid. The former is directed towards present mental acts and
operations, while the latter is directed towards past events to which
one was agent or witness. If consciousness could extend to past
events, then memory would be redundant (*Essays*, 277).




According to Reid, memory is neither necessary nor sufficient for
personal identity, metaphysically speaking, despite the conceptual and
evidential relations memory bears to personal identity. It is not a
necessary condition because each us has been agent or witness to many
events that we do not now remember. "I may have other good
evidence of things which befell me, and which I do not remember: I
know who bare me, and suckled me, but I do not remember these
events" (*Essays*, 264). It is not a sufficient
condition, for, as Butler showed, while having an episodic memory of
an event entails that one existed at the time of the event remembered,
it is not the recollection or the ability to recall that
*makes* one identical with the person who was witness or agent
to the event. "It may here be observed...that it is not my
remembering any action of mine that makes be to be the person who did
it. This remembrance makes me know assuredly that I did it; but I
might have done it, though I did not remember it"
(*Essays*, 265). Reid's fourth criticism is that while memory
is tied to personal identity conceptually and evidentially, such ties
do not entail a metaphysical connection that would license analyzing
the latter in terms of the former (*Essays*, 277).




Reid's final criticism is that the Memory Theory is committed to the
absurdity that identity consists in something that has no continued
existence (*Essays*, 278). Reid and Locke agree that memory,
consciousness, thought, and other mental operations have no continued
existence. They are fleeting and non-continuous. But they also agree
that identity, and in particular personal identity, requires a
continued existence over time. As Locke puts it, "one thing
cannot have two beginnings of Existence, nor two things one
beginning" (Locke, *Essay*, Book II.xxvii.1). But these
commitments are jointly inconsistent with the thesis that personal
identity consists in memory.




A theory of personal identity is intended to account for how a
person remains identical over time. When analyzed in terms of
items that are fleeting and non-continuous--ideas, memories,
thoughts--identity is reduced to diversity; that is, it is
eliminated. By contrast, if one locates personal identity in that
which thinks and remembers, and which has a continued, uninterrupted
existence, one purchases personal identity at the cost of admitting
that the self is a substance. Reid captures Locke on the horns of
a dilemma: either the self is a substance, in which case it remains
identical over time, or the self is not a substance, in which case
there is no personal identity. Reid holds that this dilemma
applies with equal force against any reductionist account of personal
identity that employs the theory of ideas, for example Hume's
bundle theory of the self (*Essays*, 473-474).


## 4. Personal Identity as Simple and Unanalyzable




Those familiar with the contemporary literature on personal identity,
with its emphasis on the necessary and sufficient conditions under
which a person remains identical over time, may wonder: if Reid holds
that memory is not the criterion of identity, and if Reid's substance
dualism rules out bodily identity as a criterion of personal
identity, in what *does* personal identity consist? Reid's
answer is that identity cannot be accounted for in any terms other
than itself. This is neither quietism nor epistemic humility on Reid's
part. Rather, Reid argues that the nature of personal
identity--its simplicity and indivisibility--rules out any
reductive account that appeals to notions other than identity in
explaining how a person persists over time.




Reid holds that numerical identity is, strictly speaking,
indefinable, but it can be contrasted with other relations, such as
diversity, similarity and dissimilarity (*Essays*, 263). It
requires a continued existence over time--a duration--and
requires that there be no two beginnings of existence. Because
mental states are fleeting and non-continuous they cannot remain
identical over time. A mental state may be indistinguishable from
a previous mental state, but because mental states do not have a
continued existence, no mental state at one time can be numerically
identical with another at a different time. As a result, persons
cannot be identified with their thoughts, actions or feelings
(*Essays*, 264). However, according to Reid, thoughts,
actions, feelings and all other mental operations are had or performed
by a subject that has a continued existence and that bears the same
relation to all them. The subject is an immaterial substance that
thinks, acts and feels. According to Reid, this substantial self
has no parts--it is indivisible--which contributes to its
resistance to reductive explanation. Reid appeals to
Leibniz's notion of a *monad* to describe the
indivisibility of this immaterial, substantial self (*Essays*,
264).




Though memory is not the metaphysical ground of personal identity,
it provides first-personal evidence of it. Reid notes that the
evidence we use to make judgments about our own pasts is different from
the evidence we use to make judgments about other people and their
pasts (*Essays* 266). Memory justifies first-personal
reports about one's own witnessed past, while judgments of
qualitative similarity justify third-personal statements about the
identities of other persons. I know that I was present at my
wedding because I remember being there. I know that the man I
live with was at my wedding because he looks like the man I
married.




First-personal, memorial reports about one's own past are
either true or false: if the memorial experience is a genuine episodic
memory, then it is impossible for it to testify falsely concerning
one's presence at the event remembered. This aspect of
episodic memory reports is often expressed by saying that they are
immune to error through misidentification. If the memorial
experience testifies falsely concerning one's presence at the
event remembered, then it cannot be an episodic memory. For
example, if I have an experience as of having been lost in a shopping
mall as a child, but I was never lost, I cannot be said to remember
having been lost, strictly speaking. The upshot is that
first-personal memorial reports, if they are episodic memory reports,
provide certainty concerning one's presence at the event
remembered. Because third-personal judgments about the pasts of
other persons are based on judgments of qualitative similarity rather
than episodic memory, they are never certain; they are only ever more
or less well justified (*Essays* 264-265).




It is important to notice that while Reid uses the term
'evidence,' when describing the role that memory plays in
first-personal knowledge of one's own past, memory is not
*used* by persons to justify judgments or beliefs about their
own pasts. In other words, people do not remember events and then
*conclude* from having remembered them, that it was
*they* who were witness to the events. Rather, memory
itself represents one's presence at the event remembered.
According to Reid, a memory consists in a conception of an event and a
belief, about the event conceived, that it happened to me, where the
pronoun is indexed to the person who is represented in the memory as
agent or witness. In other words, memory consists in part in a
judgment that represents one's presence at the event. Any
further judgment, justified by memory, to the effect that *I*
was the person who was there would be superfluous--memory
already testifies to my having been there. This is why Reid calls
the evidence of memory *immediate*: first-personal statements
about one's own past are memory statements, not statements made
on the basis of memory.




Reid's picture is one on which each of us is immediately and
justifiably aware of our own past because each of us *remembers*
having been there. This is the moral of the story concerning the
logical relationship between the concept of memory and the concept of
personal identity. Memories do not *make* me the same
person as the person represented in my memories. Rather, memories
allow me to know my own past, immediately and directly.