## 1. The (Traditional) Epistemological Problem



The traditional epistemological problem of other minds is often
associated with scepticism. The sceptic raises a doubt about the
possibility of knowledge in connection with the mind of another, a
doubt which is thought to follow from a more general doubt raised by
Descartes concerning our knowledge of the external world. This latter
doubt arises in stages, each of which is designed to draw us into a
more wide-reaching scepticism: at stage one it is observed that the
senses sometimes deceive; at stage two the possibility of an extended
dream is considered; and at stage three the possibility is introduced
that there is an Evil Demon deceiving me to think that there is a
world beyond how things appear. It is with the third stage that
Descartes thought we encounter the possibility of universal doubt
about an entire domain, in this case the external world. Descartes has
found a way to retreat into his own mind, where he claims to find both
knowledge and truth: I can know how things appear to me; external
things are now in doubt. Cartesian doubt is *radical* and it
has been raised by philosophers not just in connection with our
knowledge of the external world, but also of the past, induction, and
other minds.



In connection with other minds, we might press Descartes' first
sceptical consideration, thus: I am sometimes deceived about what
another is thinking or feeling. But, as with the external world, this
is not sufficient for radical doubt concerning others. Radical doubt
may be thought to arise when one presses the third sceptical
consideration, the possibility that an Evil Demon (or mad scientist)
has contrived that all others apart from myself are
automata/zombies--non-thinking, non-feeling individuals who move
in a manner similar to the way I move. We can associate a
'thin' sceptical problem with the former doubt and a
'thick' sceptical problem with the latter (Avramides
2015). The former is a problem we grapple with in our everyday lives;
the latter is a distinctively philosophical problem. It is the thick
skeptical problem that leads to the possibility of
solipsism--that I am alone in the universe.



Once one teases out a thin from a thick problem, one can ask the
following: (i) does any proposed response to the thick problem help
with the thin?; (ii) does having knowledge (in any domain) depend upon
a solution to the thick problem?; and (iii) are there any further
questions that can be raised with respect to other minds beyond those
associated with these two sceptical problems? It is fair to say that
little to no consideration was paid to question (i) in the past. It is
the threat of solipsism that largely preoccupied philosophers--at
least until more recently. Question (ii) has received much discussion
in recent decades. Epistemologists who favor an externalist approach
(e.g., Goldman, Nozick, Dretske) concentrate on the question of
*what* others think and feel. In line with the general
externalist approach, these philosophers hold that there can be
knowledge despite there being no response to the radical sceptical
challenge. Others agree that having knowledge does not require
responding to this challenge, but not because they believe that there
is no response here but because they believe that the correct account
of knowledge leaves no room for such a challenge (McDowell 1982). With
respect to (iii), Zahavi (2014) has identified a further question that
he labels the *why* question. In our everyday encounters with,
and understanding of, others we want to know not only what they think
and feel, but also why they think and feel as they do and what this
means to them.



Not everyone takes the epistemological problem here to be a radical
skeptical one. Some see the problem as arising from reflection on an
apparent asymmetry in the way I know about my own and another's
mind: in my own case, at least most of the time, I know what I think
and feel directly and without inference from any evidence (the
qualification here is designed to reflect the fact that one can, at
times, learn about one's own mental states from others--see
Austin 1946 [1979: 110]); in the case of others, all access to what
they think or feel is thought to be indirect, mediated by the
other's behavior. Hyslop, for example, writes, "the
problem of other minds is generated by an asymmetry in respect of
knowledge" (1995: 6; cf. Davidson 1991 [2001]). Gomes (2018) has
labeled the epistemological problem raised by attention to this
asymmetry the problem of *sources*, which he distinguishes from
the problem of *error*. Gomes finds the problem of sources in
the work of Austin (1946 [1979]) who begins his discussion of other
minds by asking, "How do we know that, for example, another
individual is angry?", a question which Austin distinguishes
from, "Do we (ever) know...?" (cf. Cassam 2007 and
Nozick 1981).



It is worth pausing to consider the seriousness of the problem of
knowing others. While some draw a parallel between the problem of
gaining knowledge of the past and of another mind, there is an
important asymmetry to be noted here: in the case of the past it is at
least logically possible that there should be direct knowledge, while
in the case of another mind such knowledge seems to be logically ruled
out. As A.J. Ayer writes:



> 
> 
> It can be argued that one's position to observe a past event is
> due to the accident of one's position in time.... But it is
> not an accident that one is not someone else. (1953 [1954:
> 216-217])
> 
> 
> 



(Discussions linking knowledge of other minds and the past provide a
rich vein of philosophical discussion; see, for example, Dummett 1969,
Wright 1980, and McDowell 1998.) It may be thought that there could be
a way of knowing another's mind--say by telepathy--and
that it is simply a contingent fact that this is not a way that is
open to human beings. Telepathy would allow one to know
another's thoughts and feelings by coming to share them. The
problem, however, is that if *I* have *your*
experiences, then those experiences are *mine* and not
*yours*. As Ayer writes: "In this respect telepathy is no
better than the telephone" (1953 [1954: 196]; cf. Austin 1946
and Wisdom 1940).



Philosophers, thus, find themselves saddled with the question, How do
I know that others have minds? One can put the emphasis on the word
*"*know" and raise a sceptical question parallel to
the one Descartes raises in connection with our knowledge of the
external world, or one can put the emphasis on the word
"how" and question the source of our knowledge given that
I am not in a position to have direct knowledge of the mind of
another.


### 1.1 The Argument from Analogy



While it may be the case that different considerations can give rise
to an epistemological problem concerning other minds, on the whole
what appears to have pre-occupied philosophers in the period under
consideration (mid-twentieth century) was the question of solipsism,
the question of whether I am alone in the universe. While it is often
accepted that I cannot be certain that I am not alone, it is thought
that it can be shown that we have good reason to believe that the
others I encounter are like me in having thoughts and feelings. One
form of reasoning has been taken to be "traditional" in
this connection: the argument from analogy (Blackburn 1994).
Analogical reasoning cites similarities between two things and uses
this as support for concluding that further similarities may be taken
to exist. Like all forms of inferential reasoning, analogical
reasoning is employed in order to expand knowledge in the face of
uncertainty (Bartha 2016).



A statement of the argument from analogy can be found in the writing
of J.S. Mill. In reply to the question,



> 
> 
> By what evidence do I know, or by what considerations am I led to
> believe ... that the walking and speaking figures which I see and
> hear, have sensations and thoughts, or in other words, possess
> Minds?
> 
> 
> 



Mill writes:



> 
> 
> First, they have bodies like me, which I know in my own case, to be
> the antecedent condition of feelings; and because, secondly, they
> exhibit the acts, and outward signs, which in my own case I know by
> experience to be caused by feelings. (1865 [1872: 243])
> 
> 
> 



While this argument was once popular (see, e.g., Russell 1923;
Hampshire 1952), it soon came to be considered unfit for purpose due
to the following considerations. Firstly, it was pointed out that
while this way of proceeding may work in certain domains, in the case
of other minds the conclusion is logically uncheckable (Locke 1968).
Secondly, it was considered problematic that this way of extending
one's knowledge proceeds from a single case (Locke 1968). And
thirdly, it was claimed that the very first premise of this argument
(I know in my own case) is problematic (Malcolm 1958).



Various attempts have been made to salvage the argument. Against the
first of these considerations it has been pointed out that we
successfully appeal to analogy when extending our knowledge from the
present to the past. However, Hyslop and Jackson (1972) remind us that
this defense fails to register the fact that the impossibility of
checking the conclusion in the case of other minds is *logical*
(cf.
 SS1),
 and prefer to defend appeal to analogy here by suggesting that, while
this is true, it is not "obviously relevant". They also
suggest that the fact that the conclusion here cannot be verified may
be "neutralized" by the fact that it also cannot be
refuted (1972: 169-170).



Hyslop and Jackson also propose an alternative to the standard defense
of the argument from analogy from the second of the above
considerations. The standard defense insists that the argument does
not proceed from a single case and that there are innumerable
instances and many different contexts in which one observes a mental
state and its associated behavior (Ayer 1956: 219-222); cf. Mill
who writes that analogy is an "inferior degree of inductive
evidence" that only works by providing one with an hypothesis
which is then verified by further correlations, 1865 [1872: 260]).
According to Hyslop & Jackson, however, there is no need to appeal
to multiple cases here just so long as one can establish a link
between mental states and behavior, something they claim can be done
from observation of one's own case (cf. Hill 1984). Hyslop
(1995) warns that we must be careful here not to appeal to the
(invalid) principle that like effects (behavior) have like causes
(mental states)--your behavior may have a purely physical cause.
We should instead appeal to the (valid) principle that like causes
have like effects: what I observe in my own case leads me to
hypothesize that my mental states are caused by physical states of my
body, and I can argue that like physical states in others will cause
like mental states. This, in effect, is to invoke the principle of the
Uniformity of Nature; it is this principle that Hyslop believes lies
at the heart of the argument from analogy. While many consider that
generalization from a single instance is a crucial weakness in the
argument from analogy, Hyslop takes this to be the argument's
strength. Indeed, he holds that the other main contender in the field,
the argument from scientific inference/best explanation fails
precisely because it does not take into account a crucial dependence
on our own case when it comes to knowledge of other minds (cf.
 SS1.2).



The third of the arguments that have been brought to bear against the
argument from analogy requires careful consideration. The very premise
that Hyslop believes recommends this way of supporting one's
belief in other minds is the one that some have thought to be
irremediably problematic. Malcolm, inspired by the later work of
Wittgenstein, has suggested that the premise--I know from my own
case what it is like to think and feel--is committed to what he
calls the "fundamental error" of thinking that one learns
what thoughts and feelings are from one's own case (Malcolm
1958: 974). This way of coming to learn about mind is associated with
what is sometimes thought of as an 'inward glance' or
introspection (cf. Locke 1689). It has been argued that this way of
learning about mind or mental states is committed to the possibility
of a private language (Wittgenstein 1953; Malcolm 1954). According to
Malcolm, Wittgenstein advances both an "internal" and an
"external" attack on the possibility of such a language
(Malcolm 1954 [1966: 75]). The internal attack aims to show that,
while a genuine language requires that one be able to articulate
correctness conditions for the application of a word, it is not
possible to articulate such conditions when the referent of the word
is not intersubjectively available. As Wittgenstein points out:
"Whatever is going to seem right to me is right. And that only
means that here we can't talk about 'right'"
(1953: SS258). (For a statement of the "external"
attack here see
 SS2.)
 The private language argument aside, the suggestion that I can come
to know about mental states from my own case leads to a conception of
mind as something not observable in behavior but as something lying
behind and causing behavior. Malcolm contrasts this way of thinking
with what he labels a *criterial* view of the relationship
between mind and behavior. Much ink has been spilled over trying to
understand this proposed alternative way of thinking of mind in
relation to behavior (see
 SS1.3).
 However we understand this proposal, it is important to appreciate
the difficulties thought to be associated with the idea that one
learns from one's own case what it is to think and feel: it is
believed to lead inexorably to solipsism. (This was something arguably
first appreciated by Thomas Reid; see
 SS4.1).
 It should, however, be noted that solipsism comes in two varieties:
epistemological and conceptual. While the argument from analogy is
proposed as a way of avoiding the former, it is arguable that it is
really the latter to which Malcolm and others are drawing our
attention. In effect, the claim here is that use of the argument from
analogy as a way of avoiding epistemological solipsism (the only mind
I can know is my own) falls foul of conceptual solipsism (the only
mind I can think about is my own). Discussion of the conceptual
problem in connection with other minds may be thought to take us in a
direction at odds with that taken when one approaches these matters
from an epistemological perspective (for the conceptual problem see
 SS2.)


### 1.2 Best Explanation



The argument from best explanation has been advocated as an advance on
the argument from analogy. While Hyslop insists that any justification
for one's belief in other minds must make crucial reference to
one's own case, it has been argued that *not* needing to
rely on such reference makes the argument from best explanation
preferable as an account of how we justify our belief here (Pargetter
1984). Whether or not one pauses to assess the relative merits of
these two ways of defending the rationality of our belief in other
minds, what is undoubtedly the case is that the argument from best
explanation is--either explicitly or implicitly--a form of
argument that enjoys wide acceptance today. David Chalmers, for
example, writes, "It ... seems that this [argument from
best explanation] is as good a solution to the problem of other minds
as we are going to get" (1996: 246).



While the argument from analogy was once popular in science (Hyslop
& Jackson (1972) cite the example of the discovery of helium on
the sun to have a characteristic spectrum by analogy with the
characteristic spectrum of helium on earth) in more recent times
science has tended to proceed in accordance with the principle that it
is rational to believe that hypothesis that provides the best
available explanation of a particular phenomenon at a given time. This
style of argument is sometimes referred to as abduction, and it is
placed alongside deduction and enumerative induction as another form
of inferential reasoning. While simple enumerative inductive takes one
from certain observations to the conclusion that one can expect more
of the same, abduction allows for the introduction of entities that
are not just unobserved, but that are unobservable (Lipton 2000;
Harman 1965).



It is claimed that my reason for believing that others have minds
similar to my own can be taken to be the same as the scientific
realist's reason for believing in the existence of electrons or
other theoretical entities. On this way of thinking, mental states are
taken to be inner states of an individual that provide the best
explanation of the behavior we observe in others; any other
explanation would be implausible. Pargetter (1984) considers the
following as implausible alternative hypotheses: (i) God is working
others like puppets; (ii) I am unique in having mental states as the
cause of behavior; and (iii) that others have mental states but they
are of an entirely different nature to my own.



According to Pargetter, the argument from best explanation is able to
bypass all criticisms standardly brought to bear against the argument
from analogy, as it relies solely on the explanatory power of the
proposed hypothesis--in this case, that others have minds. This
form of reasoning is also held to be superior to reasoning from
analogy as it can be used to establish the existence of minds in
individuals of other species whose behavior may not be similar to mine
or who think and feel in ways that are *dis*similar to the way
that I think and feel. It may also be used to justify the belief in
minds of (abnormal) humans who may either behave very differently or
think and feel very differently from their conspecifics.



Melnyk (1994) has argued that there is an important disanalogy between
the scientific realist's reason for believing in theoretical
entities and an ordinary person's reason for believing that
other people have minds. His argument rests on the observation that
gross behavioral evidence is insufficient for belief in another mind
without additional reference to what one knows from one's own
case. Melnyk can be read as advocating a hybrid account of our
knowledge here, incorporating elements from the argument from analogy
as a supplement to the inference from best explanation. But he also
makes the following, important, observation: "A complete
response to the problem of other minds seems obliged to incorporate
more than one approach, and may have to incorporate several"
(1994: 487). This is an observation others have also begun to advocate
(see
 SS3.2).


### 1.3 Criteria



It has been suggested that an alternative to the view that mind lies
behind and serves as the cause of behavior is the view that behavior
serves as the *criterion* of mind (see
 SS1.1).
 The former conception of mind in relation to behavior is associated
with the following ideas: (i) my mind is private to me; (ii) I am both
infallible and incorrigible with respect to my own mental states; and
(iii) I can know my own mental state without having to observe
anything about my body. This picture of mind is bolstered by the
thought that, whatever another person says or does, it is always
possible that they are deceiving me about what is going on in their
minds--an extreme version of which leads to the thought that I am
entirely deceived and all others are mere automata or zombies. In
short, this conception of mind leads to the traditional
epistemological problem of other minds. Standard responses to this
problem--arguments from analogy and best explanation--draw a
parallel between knowledge of another's mind and explanation in
science. In this connection Wittgenstein writes: "Misleading
parallel: psychology treats of processes in the psychical sphere, as
does physics in the physical" (1953: SS571). In *The Blue
Book* (24-25) Wittgenstein contrasts the business of citing
criteria with that of giving symptoms in answer to the question,
"How do you know?" He associates the giving of symptoms
with the making of hypotheses; he associates the citing of criteria
with "the grammar (the use)" of a word or with linguistic
convention (1958: 23).



It has not proved an easy thing for philosophers to understand what
Wittgenstein means here (see Albritton 1959; Shoemaker 1963; Kenny
1967; Baker 1974). What one can say is that a criterial relation
between mind and behavior is designed to be distinct from, on the one
hand, logical entailment, and on the other, inductive inference. Some
see a connection between a criterial relation here and the possibility
of perceptual knowledge of another's mind (McDowell 1982, Hacker
1997; see
 SS1.4.1).
 Those that advocate a criterial relation between mind and behavior
also tend to understand the problem of other minds to be a conceptual
one (see
 SS2).
 As well as being associated with the rejection of a certain
conception of mind that can be labeled 'Cartesian', appeal
to a criterial relationship between mind and behavior is often thought
to form part of an anti-sceptical stance in connection with
others.



Some have seen in the appeal to criteria nothing but a form of
behaviorism. Chihara and Fodor (1965) are among such philosophers, and
their work has served to turn the tide against talk of criteria as a
way of understanding the relationship between mental states and
behavior. Chihara and Fodor sum up the Wittgensteinian argument as
follows: if we are justified in claiming that one can tell or
determine that a predicate '*Y*' applies on the
basis of the presence of *X* then either *X* is a
criterion of *Y* or *X* can be shown to be correlated
with *Y*. They then claim that this overlooks the possibility
that in some cases the justification for the application of a
predicate rests on an appeal to the "simplicity, plausibility
and predictive adequacy of an explanatory system as a whole"
(1965: 411). They point out that scientists use this method of
explanation when it comes to the detection of particles that are not
directly observable (see
 SS1.2).
 Chihara and Fodor agree with the Wittgensteinian who holds that the
child does not learn about mental states by introspection but rather
learns about complex relations between mental states and behavior in
the course of learning her language, but they point out that part of
what the child learns is how to explain another's behavior by
reference to her thoughts and feelings and suggest that this may be
the result either of explicit training or of an innate capacity.



Whether one is persuaded by Chihara and Fodor's position against
appeal to criteria will depend in part upon one's assessment of
the correctness of thinking about mental states on the model of
unobservables in science. Furthermore, it may be thought that to
understand mental states to be entirely explanatory phenomena is
arguably to lose sight of the subjective aspect of these states.
Finally, to think of mental states as lying behind and causing
behavior may be thought to break what some see as a deep connection
between mentality and behavior, thereby opening up the possibility
that I am alone in the universe (Avramides 2013).



Many have continued to defend a criterial approach here. Crispin
Wright and John McDowell have written extensively on this topic, each
offering a very different interpretation of the notion of a criterion.
While the debate here is complex and interwoven with issues such as
realist vs anti-realist semantics, there is one thread in this debate
that is particularly relevant to the epistemological problem of other
minds: the question of whether criteria should be thought of as
defeasible or indefeasible. Wright rightly sees this question as
connected with the question of whether appeal to criteria can provide
one with an anti-sceptical stance. Wright's own understanding of
criteria turns on an important distinction between *constituting
knowledge that P* and *an entitlement to a knowledge-claim that
P*. While a sceptic can always challenge the truth of any claim to
know that which lies beyond the cognitive reach of the subject
(examples here include the past and other minds), Wright suggests that
the sceptic can make no inroads when one pulls in one's horns
and simply makes a statement about the reasonableness of one's
belief or claim to know in such cases. He then argues that
reasonableness is secured if one can show that the criteria for the
claim that, for example, another is in pain are satisfied and one
knows of no consideration that would defeat the claim--in other
words, just so long as one is using a word, e.g., "pain",
in accordance with the conventions in play in one's linguistic
community. It is a consequence of this understanding of criteria that,
while one may be in the best position to make a claim to know that Tom
is in pain by observing his behavior, one's claim is
defeasible--that is, it is open to being shown to be mistaken in
the light of further evidence. Importantly, to hold that behavioral
criteria are defeasible is not, according to Wright, to be committed
to understanding behavior as 'outer' evidence (a symptom)
of the other's 'inner' mental states. Wright admits,
however, that his position leaves room for scepticism: "a form
of scepticism that is endemic in the very practice of assertion"
(1984: [1993:
 389-390]).[2]



McDowell is not content to concede any ground to the sceptic, and
believes that appeal to criteria can confer (sceptic-proof) knowledge.
But for this to be the case, criteria must be understood to be
*in*defeasible (McDowell 1982). McDowell finds an
incompatibility between, on the one hand, the legitimacy of a
knowledge ascription and, on the other, the possible of its falsity
(its defeasibility). McDowell is not persuaded by Wright's
understanding of criteria, and proposes an alternative to it.
McDowell's understanding of criteria is thought to form a part
of his defense of a direct, perceptual, account of our knowledge of
other minds (see
 SS1.4.1).



In the work of Stanley Cavell one finds yet another understanding of
criteria: "Criteria are 'criteria for something's
being so", not in the sense that they tell us of a thing's
existence, but of something like its identity, not of its
*being* so, but of its being *so*. Criteria do not
determine the certainty of statements, but the application of the
concepts employed in statements" (Cavell 1979: 45; for a good
discussion of Cavell's understanding of criteria see Mulhall
1994, Pt. II,). I may come to know that the criteria for pain have
been satisfied, but this does not touch the question of whether the
other *really* experiences thoughts and feelings (the thick
sceptical question). Cavell insists that, rather than reply to the
sceptic or show why this thick sceptical question does not arise
(inferential arguments attempt to do the former, appeal to criteria
have been used by some to do the latter), we need to understand what
it is that gives rise to the sceptic's worry. Cavell urges that
we see the sceptic as being motivated by a genuine concern, but one
that s/he misunderstands to be an epistemological concern. Rather than
ask, How can I know the thoughts and feelings of others?, Cavell
thinks we should look to how how I respond to the other. He draws
attention to the *Philosophical Investigations* (p. 178) where
Wittgenstein writes, My attitude towards him is an attitude towards a
soul". Cavell sees in this attitude an acknowledgement of
another. Acknowledgment is active, it is something we do in relation
to another; it is not a cognitive achievement. With his emphasis on
acknowledgement, Cavell aims to turn us away from the idea that my
fundamental relation to others is a cognitive one (see Cavell, 1979,
Pt. IV, and Avramides 2023). 


### 1.4 Perceptual Knowledge of Other Minds



Those who defend either the argument from analogy or from best
explanation are firmly of the view that any knowledge we may have of
other minds (or any justification there may be for our belief in them)
must be indirect. They accept that, while our knowledge of our own
mental states is direct, our knowledge of the mental states of others
must proceed by reasoning from what we observe--the other's
behavior--to what we cannot observe--the other's
mental
 states.[3]
 The idea that the mind of another is not directly observable is one
that seems common to many philosophers. As early as the fifth century
AD, St. Augustine writes: "For even when a living body is moved,
there is no way opened to our eyes to see the mind, a thing which
cannot be seen by the eyes..." (*De Trinitate* 140;
cf. Descartes 1641, Second Meditation; and Berkeley 1710, Principle
148) The idea that we should have direct knowledge of another's
mental states has also come under fire more recently by Colin McGinn,
who writes that direct perceptual reports specifying the mental states
of another "seem definitely wrong" (1984: 123, n. 2; cf.
Plantinga 1966: 441).



Direct knowledge is often associated with perception and it is this,
as we have just seen, that so many philosophers have rejected in
association with other minds. While our knowledge of the world of
things around us is taken to come about through perception, it has
been thought that knowledge of another's mind cannot come about
by this
 means.[4]
 Nonetheless, we find Nathalie Duddington writing, "My object in
the present paper is to maintain that our knowledge of other minds is
as direct and immediate as our knowledge of physical things"
(1919: 147). It is not at all clear that philosophers at the time paid
much attention to this very interesting paper, but philosophers today
have found in Duddington's work a precursor for an idea that has
come to be taken very seriously--at least in some
 circles.[5]



Many analytic philosophers in the past few decades have written in
defense of the idea that our knowledge of other minds comes about
through perception (e.g., McDowell 1978 and 1982, Dretske 1969 and
1976, Cassam 2007, McNeil 2012, Stout 2010, and Green, 2010). The idea
is also defended by some philosophers writing in the phenomenological
tradition
 (SS1.4.2).
 Many philosophers working today bring together work in both
traditions in defense of this idea (e.g., Overgaard 2019, Krueger
2014, and J. Smith 2010). Consideration of issues to do with the self
in relation to others has been thought by some to have the power to
bridge the chasm between these two traditions in philosophy.


#### 1.4.1 McDowell and Dretske on perceptual knowledge of other minds



Those attracted by the idea that our knowledge of other minds comes
about through perception often appeal to the following in defense of
their position: we all acknowledge that we often claim to be in the
position where we can *just see* that another is angry, in
pain, and the like. These philosophers are careful to point out that
we don't always claim that this is the case and we do not claim
it with respect to all mental states, but they hold that attention to
such cases can teach us that the mental is not always "withdrawn
from direct engagement with the world" (McDowell 1995: 413).
Duddington writes that to say that knowledge of another's mind
can be direct and immediate is to say that there is no veil or barrier
intervening between the knowing subject and what is known--it is
not to say either that our knowledge here is complete or that there
are no difficulties that stand in the way of our attainment of such
knowledge (1919: 167; cf. McDowell 1982).



McDowell has written that



> 
> 
> we should not jib at, or interpret away, the common-sense thought that
> ... one can literally perceive, in another person's facial
> expression or his behavior, that he is in pain, and not just infer
> that he is in pain from what one perceives. (1978: 305)
> 
> 
> 



McDowell's perceptual account involves two crucial moves, one
concerning our understanding of experience and the other concerning
our understanding of behavior. He proposes that we think of our
experience as being "open" to the world, allowing objects
to figure in it directly; and in a parallel fashion he proposes that
we think of behavior as giving expression to mental states thereby
allowing them to figure in behavior (McDowell 1982, 1986). According
to McDowell, when one has an experience of genuinely expressive
behavior, one is not actually experiencing the mental state of the
other; nonetheless, behavior in the veridical case should not be
thought to fall short of mind in such a way as to allow for the
possibility of its total absence. McDowell believes that this
understanding of experience and behavior can support (sceptic-proof)
knowledge of both the world and other minds.



The challenge for McDowell is to explain how error can arise in both
cases. To accommodate error, McDowell introduces a disjunctive
understanding of both experience and behavior (McDowell 1982; Soteriou
2016). Considering the former we can say: *either* our
experience is such as to yield access to the world *or* it is
such as to yield only apparent access. Considering the latter we can
say: *either* the observed behavior is such as to be expressive
of the other's mentality *or* it only appears to be such.
In both cases the way things seem to the experiencing subject is such
as to fall short of infallible knowledge as to which disjunct is in
question (McDowell 1986 [1998: 240]). We may be fallible with respect
to how things are in the world, but McDowell insists that we must be
careful to locate this fallibility in the right place. We should not
conclude, as so many have, that all experience may be fallible; this
is the move that paves the way for radical scepticism. It is, rather,
our perceptual capacities that are fallible: sometimes they provide us
with experience which is veridical and sometimes they do not (McDowell
2006). The important thing is that, when experience is veridical, we
can take it to give us (sceptic-proof) knowledge of the world.



When it comes to our knowledge of other minds, the disjunctive move
allows us to hold that, where behavior is genuinely expressive of
another's mental life, there our experience of her behavior will
yield (sceptic-proof) knowledge of another's mental life.
Genuinely expressive behavior is being thought of not as evidence (a
symptom) of another's mental life but as a criterion of it.
This, McDowellian, understanding of criteria--in contrast to
Wright's
 (SS1.3)--requires
 that we accept behavior in at least some cases to be expressive of, a
criterion of, mental states. So understood, behavioral criteria are
*in*defeasible. This is not to say that error is not possible,
as the person I encounter may be deceiving me. However, in such cases
the criterion for the mental state is not satisfied. The important
thing is that this possibility should not be taken to negate the fact
that, when the other person is not deceiving me, my experience of her
behavior can result in (sceptic-proof) knowledge that she is, for
example, in pain. The genuine possibility that others may deceive me
should not be taken to open up the possibility that all others may be
zombies and that I am in the world
 alone.[6]
 (We may here consider something Wittgenstein writes (1992, 94e):
"But of course it isn't true that we are never certain
about the mental processes in someone else. In countless cases we
are.")



Dretske's defense of our direct, perceptual knowledge of another
mind differs significantly from the one that is found in the work of
McDowell or Duddington. Dretske is not interested in scepticism, or in
giving an account of knowledge that is sceptic-proof. He is interested
only in saying how it is that we come to know what others think and
feel, to identify the source of our knowledge here (cf.
 SS1).
 While we often say that we just can see what another is thinking or
feeling, it is also thought that there is an obstacle to taking
perception to be a possible source of this knowledge. Dretske
identifies the obstacle here to arise from the fact that it is
generally thought that another's mind is unobservable: while one
can see the smile, the clenched fist or the hunched shoulder, one
cannot see what lies behind these things (Dretske 1973: 36). While
Dretske agrees that you cannot see another's joy, anger or
depression, he believes you can see (the fact) that another is happy,
angry or depressed. The distinction here goes along with another that
Dretske draws between what he calls "non-epistemic" and
"epistemic seeing". The former is a relation between a
person and a thing (Dretske likens this relation to stepping on a
bug), while the latter has "positive belief content"
(Dretske 1966). He points out that just as one can see that someone is
wealthy without seeing their wealth, or see that the metal rod is hot
without seeing the heat, so one can see that another is happy, angry,
depressed and the like without seeing the other's joy, anger or
depression (Dretske 1966 and 1973). Dretske suggests an analysis of
epistemic seeing, which analysis contains an all-important reliability
condition: the conditions under which, for example, Sally sees that
Tom is angry must be such that Tom would not look angry to Sally
unless he was angry. It is the satisfaction of this reliability
condition that allows the satisfaction of the analysis to amount to
both a visual and an epistemic
 achievement.[7]



Dretske appreciates that a given behavior on Tom's part is not
always a reliable indicator of, say, anger. What he holds is that
under certain conditions and to those who know Tom well--such as
his wife--his behavior can be taken to be a reliable indicator of
his anger (for a critique of this idea see Avramides 2019). Therefore,
according to Dretske, we can have direct perceptual knowledge of
another's mental states in the following sense: we can see what
others are feeling andand thinking, even though we cannot see
another's mental states or know that solipsism is
 false.[8]



Quassim Cassam brings the work of Dretske together with that of
McDowell in his defense of a perceptual account of our knowledge of
other minds (Cassam 2007, ch. 5). Cassam uses Dretske's work to
show that one can know what another thinks and feels despite the fact
that one cannot see another's mental states. But rather than
follow Dretske in holding that behaviour is a reliable indicator of
another's mental states, Cassam follows McDowell and holds that
behaviour manifests another's mental states. Behaviour,
according to Cassam, is revealing of another's state of mind
without being that state of mind (Cassam 2007, 165). The result of
bringing the work of these two philosophers together allows Cassam to
claim that I can know both *what* another thinks and feels
and *that* he is a thinking, feeling being. Dretske, on the
other hand, holds that I can only know what another thinks and feels.
According to Dretske, that another is a genuine thinking, feeling
being is not something that can be known; rather, this is a
presumption or presupposition (for a discussion of Cassam's work
in relation to McDowell and Dretske see Avramides 2023). 


#### 1.4.2 Perceptual knowledge of other minds and the phenomenological tradition



The late 19th and early twentieth centuries saw the
emergence of the phenomenological movement associated with such
figures as Husserl, Heidegger, Merleau-Ponty and Sartre. One important
dimension of the work of these philosophers is discussion of
intersubjectivity. There are two other philosophers in this tradition
whose work is also strongly associated with intersubjectivity, Max
Scheler and Edith Stein. It can be said of the phenomenological
approach as a whole that it rejects the isolationism of the self that
characterizes Cartesian philosophy. Scheler specifically criticizes
the argument from analogy, claiming (i) that it is mistaken in its
starting point or first premise and (ii) that it wrongly assumes that
we cannot have access to another's mind.



The first premise of the argument from analogy is, in effect, the
Cartesian starting point: one is secure in the knowledge that one has
of one's own conscious experience. These phenomenologists reject
this starting point. In its place Husserl (1931) adopts the starting
point of embodied subjectivity, Heidegger (1927) insists that the
structure of human experience is such as to involve a relation to the
world and to others (*Dasein* is essentially characterized by
*Mitsein*), and Merleau-Ponty holds that "I find myself
already situated and involved in a physical and social world"
(1945 [2003: 419]). Sartre takes things further and draws attention to
the extent to which the encounter with another is an encounter with
someone who takes me as an object (1943).



These philosophers refuse to allow themselves to be pre-occupied by
the epistemological issues that they see as arising from a mistaken
starting point. Instead of asking how I can justify my belief in the
world and others, they take for granted that the individual's
experience is such as to exist in a world and for others and address
questions that concern this starting point, such as: what makes this
starting point possible (Husserl & Merleau-Ponty); how can we
explain/understand the structures of the being of subjectivity in such
a way as to include the world and others (Heidegger); how do I
encounter the Other (Sartre). Crucial to the defense of this
non-Cartesian starting point is a non-Cartesian conception of mind in
relation to body. The conceptual divide between mind and body that one
finds in Descartes' philosophy is taken by these thinkers to be
"inadequate to phenomenology" (Overgaard 2006).



These phenomenologists also reject the idea that we cannot have access
to the mind of another. Scheler points out that



> 
> 
> we believe ourselves to be directly acquainted with another
> person's joy in his laughter, with his sorrow and pain in his
> tears, with his shame in his blushing
> 
> 
> 



and the like (1913 [1954: 260]). And in the same paragraph Scheler
insists that we should not allow philosophical theory to tempt us away
from the obvious: that we know the minds of others through perception.
In a similarly vein, Merleau-Ponty (1945 [2003: 415]) writes:



> 
> 
> I perceive the grief or the anger of the other in his conduct, in his
> face or his hands, without recourse to any 'inner'
> experience of suffering or anger....
> 
> 
> 



Scheler suggests that philosophical theory tries to turn us away from
the obvious by insisting that "there is certainly no sensation
of another person's mind nor any stimulus from such a
source", and he insists that to think like this is to turn
one's back on the "expressive unity" of behavior
(1913 [1954: 181]). He writes: "We can ... have insight
into others, in so far as we treat their bodies as a field of
expression for their experiences" (1913 [1954: 10]). Whether we
take knowledge here to come about either as the reult of an inference
(as in the argument from analogy) or though perception turns,
according to Scheler, on the question of how one views the
relationship between mind and behavior.



Scheler considers a crying child and the various responses that one
may have to her. Firstly there is the possibility that one sees the
face but does not see it as expressing distress. Secondly there is the
possibility that one sees the face as expressive of distress while
remaining indifferent. And finally, there is the situation where one
sees the child's distress and responds emotionally. Scheler
associates empathy with the second situation, and labels the emotional
response in the final situation
 "sympathy."[9]
 The relationship between perception and empathy is explored in
somewhat more detail in the work of both Husserl and his student Edith
Stein. While Husserl struggles with the idea of empathy in relation to
others throughout his career we find in Stein's work a more
settled view (Zahavi 2014). Stein distinguishes empathy from
perception, holding that empathy "is a kind of act of perceiving
*sui generis"* (Stein 1917 [1989: 5]): it is like
perception in so far as it is *direct* (like Scheler, Stein
rejects the idea that knowledge of others comes about through
inference); it is unlike perception in the way in which it gives us
its object. Empathy is the way in which we experience *foreign*
consciousness. Stein follows Scheler in holding that our experience of
the other is an experience of a soul which is "always
necessarily a soul in a body" (1917 [1989: 44]), but she
emphasizes the way in which this experience is always imperfect: there
is always a distance between what I am aware of when I empathize with
the other and what the other is experiencing; I experience the other
*as other*, as a center of intentionality or as a perspective
on the world that is different from mine (cf. Zahavi 2014: 192).
Without the distance introduced by an imperfect understanding--if
understanding here could be perfect--I would be the other (cf.
Levinas 1979: 89: "the absence of the other is exactly his
presence as other"). It is this distance that Stein accuses
Scheler of failing to capture in his more straightforwardly perceptual
 account.[10]
 As well as appreciating the otherness of the other, there is an
appreciation in the work of Stein and Scheler of the ethical nature of
my encounter with the other (cf. Levinas, Wittgenstein and
Cavell).


#### 1.4.3 Indirect vs direct accounts



It is sometimes taken to be the case that perception and inference
exhaust the alternatives when we consider how we might account for our
knowledge of others. But, as we have seen in
 SS1.4.2,
 Stein's account eschews a straightforwardly perceptual account
of our knowledge here without yet succumbing to an inferential one. It
may be more fruitful if one thought of the opposition here to be
between indirect and direct accounts of our knowledge of others. What
many who oppose inference are against is the mind-body relationship
upon which it is based. Many who reject indirect accounts are opposed
to an idea that they see as lying at the heart of such accounts
- the idea that the behaviour of the other acts as a veil
cutting me off from the other's mental states. Once this idea is
rejected, it remains open how to understand direct accounts. McDowell
suggests two possible interpretations. On the first, the fact of the
other's mental states is presented to view; on the other,



> 
> 
> ... we might think of what is directly available to experience in
> some such terms as "his giving expression to his being in the
> 'inner' state": this is something that, while not
> itself actually being the "inner" state of affairs in
> question, nevertheless does not fall short of it.... (McDowell
> 1982, 472-3). 
> 
> 
> 



Those that advocate a direct account of our knowledge of other minds
are faced with the following question: does their account entail a
rejection of the asymmetry that philosophers have identified between
knowledge of one's own and another's mind (see
 SS1)?
 Some philosophers who propose a direct account would insist that they
can still allow for an asymmetry here, just so long as we are careful
how we understand
 it.[11]
 They believe that we must be careful not to understand the asymmetry
here as committing us to a picture of mind as lying behind behavior.
One alternative to this picture can be found in the work of
Merleau-Ponty who writes,



> 
> 
> The grief and anger of another have never quite the same significance
> for him as they have for me. For him these situations are lived
> through, for me they are displayed. (Merleau-Ponty 1945 [2003:
> 415])
> 
> 
> 



(Cf. Wittgenstein 1992: 10e, who writes: "My words and my
actions interest me in a completely different way than they do someone
else ... I do not relate to them as an observer".)


## 2. The Conceptual Problem of Other Minds



Thomas Nagel once wrote:



> 
> 
> The interesting problem of other minds is not the epistemological
> problem.... It is the conceptual problem, how I can
> *understand* the attribution of mental states to others. (1986:
> 19-20)
> 
> 
> 



Bilgrami agrees (1992). Some philosophers go further than Nagel and
insist that the conceptual is the fundamental problem; others see
little in it (Hyslop 1995). How one understands this problem is a
matter of some contention (Gomes 2011). What all agree is that the
problem is associated with the work of Wittgenstein, and in particular
section 302 from the *Philosophical Investigations*:



> 
> 
> If one has to imagine someone else's pain on the model of
> one's own, this is none too easy a thing to do: for I have to
> imagine pain which I *do not feel* on the model of pain which I
> *do feel*. That is, what I have to do is not simply to make a
> transition in imagination from one place of pain to another. As, from
> the pain in the hand to pain in the arm. For I am not to imagine that
> I feel pain in some region of his body....
> 
> 
> 



Malcolm understands 302 as providing an "external attack"
on the possibility of a private language (contrast the argument of
 SS1.1).
 That is to say, 302 is designed to show the difficulty that one runs
into if one begins with the idea that one knows from one's own
case what it is to feel pain: one risks conceptual solipsism.
 [12]
 Colin McGinn has suggested that the problem raised in 302 can be
thought of in the following way: if I learn through introspection what
it is, say, to be in pain, then there is a "a way of thinking
about my experiences which (a) only I have and (b) enters into my
understanding of the concept in question" (1984: 127). The way I
learn about the object of my thought here is as something that has a
"distinctively first-person element" from which it seems
impossible to prescind (*ibid*). This explains why I can make a
transition from the pain in my hand to the pain in my arm, but it is
"none too easy a thing" to make a transition from a pain
that I feel in my hand to a pain that you feel somewhere in your body
(for a very different interpretation of the 302, see Kripke 1982,
*Postscript*).



Some associate the conceptual problem here with the problem of coming
to have mental concepts that are completely general. Gareth Evans has
proposed that to have a thought about an object to the effect that it
is *F* (consider: Tom is angry) requires the exercise of the
following two capacities:



> 
> 
> One being the capacity to think of *x*, which could be equally
> exercised in thoughts about *x* to the effect that it is
> *G* or *H*; and the other being a conception of what it
> is to be *F*, which could be equally exercised in thoughts
> about other individuals, to the effect that they are *F*.
> (1982: 75)
> 
> 
> 



Evans labels this the "generality constraint"
(*Ibid,* ftnt. 15), and it has been thought to raise a problem
for thoughts about mental states if one takes it that one comes to
know what a mental state is by inward reflection alone. The problem,
reflected in 302, is how to understand the extension to others of a
concept acquired in this way.



P.F. Strawson in effect acknowledges the generality constraint when he
writes:



> 
> 
> It is a necessary condition of one's ascribing states of
> consciousness, experiences, to oneself, in the way that one does, that
> one should also ascribe them, or be prepared to ascribe them, to
> others who are not oneself. (1959: 99)
> 
> 
> 



Strawson considers how it is that one ascribes mental states to others
and concludes that one cannot do this if we insist on divorcing mental
states from the behaving body. Strawson claims that we must
acknowledge what he calls the "primitiveness of the concept of a
person", the concept of



> 
> 
> a type of entity such that *both* predicates ascribing states
> of consciousness *and* predicates ascribing corporeal
> characteristics ... are equally applicable.... (1959:
> 101-2)
> 
> 
> 



While many will accept that the conceptual problem is the
*first* problem we encounter in connection with others, others
go further and claim that once one addresses the conceptual problem
there is no room for the epistemological one. This is because our way
of thinking and talking about mind will have application to others
built into it from the start. It has been pointed out that to say what
is required for grasp of a concept is not yet to show that that
concept is
 instantiated.[13]
 It can be said in reply that it is a particular proposed solution to
this conceptual problem that may be thought to make the
epistemological question otiose. As we can see with Strawson's
proposal, the idea is that we break down the gap between mind and
behavior and understand what one experiences when one sees
another's behavior as itself requiring mental state attributions
to the other. Some can only see in this proposal a retreat into
behaviorism. Others, however, insist that this is not the
case--at least if behaviorism is understood as a reductionist
thesis. It is not reductionist to hold that behavior is expressive of
another's mental life; genuinely expressive behavior is held to
be distinguishable from 'mere behavior' (cf. Austin
1946).



McDowell claims to echo Strawson's work when he writes in this
connection that we must regain the concept of a *human being*
from what he takes to be a "philosophically generated"
concept of a *human body* (McDowell 1982: 469; cf. Cook 1969).
Some take issue with McDowell over whether the latter is only a
philosophically generated concept (Wright 1998), but it is hard to
deny that the move from the former concept to the latter is deeply
significant.


## 3. The Naturalist Turn



Alvin Goldman (2006) has distinguished a descriptive from a normative
epistemological problem of other minds.
 Section 1
 and
 section 2
 were largely concerned with the latter; this section will concern
itself with the former. The descriptive problem is associated with
what Goldman terms *mind reading* (or *mentalizing*).
Mind reading involves the capacity to think about mind and is a second
or higher order activity that involves representing or conceptualizing
others (as well as oneself) as "*loci* of mental
life" (Goldman 2006: 3). While many species of animal may be
thought to have minds, only some will be capable of representing
another as having minds. Questions of justification and conceptual
difficulty are not of concern to the descriptive theorist, nor are
metaphysical questions concerning the nature of mind; what concerns
the descriptive epistemologist is how what she says measures up with
what is being learned in the empirical disciplines of developmental
psychology and neuroscience. Work on the descriptive problem is
developing at a rapid pace and, while at first attention in all the
relevant disciplines was concentrated on two prominent accounts of
mind reading--theory-theory and simulation theory--a variety
of accounts now exist which challenge both of these accounts (see
 SS3.2).


### 3.1 Theory-Theory and Simulation Theory



Theory-theory has its roots in a paper by Premack and Woodruff (1978),
which argued that certain problem-solving behavior observed in
chimpanzees should be taken as evidence that they possess a theory of
mind, as evidence that they are able to make predictions about the
behavior of others that impute to them unobservable mental states.
Premack and Woodruff take this imputation to be a rather primitive and
unsophisticated reaction to the observation of certain behavior, so
natural in both humans and chimpanzees that it would take an effort to
suppress
 it.[14]



In their commentaries on this paper (1978), Dennett, Bennett, and
Harman pointed out that further experimentation was required in order
to determine whether a creature possesses the concept of belief (which
concept is required in order to have thoughts about another's
mental states). In particular, it would need to be shown that the
creature possesses the concept of *false belief*. Wimmer and
Perner (1983) devised a test that purported to show just that. The
original test was carried out with normally developing human children
and taken to show that the capacity to represent false beliefs is
present in 4 to 6 year olds, but absent in 3 year
 olds.[15]
 Two different proposals have been put forward to explain this
developmental change. One proposal (see, e.g., Gopnik & Wellman
1992) suggests that the child possesses a naive psychological
theory that it uses to explain and predict the behavior of others and
that gets revised by the child over time. The other proposal (see,
e.g., Leslie & Roth 1993) suggests a native, domain-specific (or
modular) mechanism that matures at a certain point as what explains
the child's success with the false-belief test.



This approach to understanding how we attribute mental states to
others has several notable features: (i) it dovetails with the
dominant approach to solving the knowledge-of-other-minds problem as
it proposes that our belief here is the result of postulating mental
states as the best explanation of observed behavior; (ii) it dovetails
with a functionalist account of mind; and (iii) it can solve the
asymmetry problem, as some hold the child comes to attribute mental
states to herself on the same model as she does others (Gopnik 2009).
All three features of this theory have come under criticism. This
approach has also been challenged by further empirical work that
purports to show that infants as young as 15 months have the concept
of false belief (Onishi & Baillargeon 2005). One suggestion to
accommodate this data is that we postulate two systems: one that
operates in the infant and that is fast, efficient, inflexible and
non-normative, and another that develops later (and operates in tandem
with the earlier one in the mature human) and that is effortful,
inflexible, normative and language-dependent (Apperly and Butterfill
2009; for a good summary of this work and a critique of it, see Jacob
2019). Much recent work has challenged the conclusion that the child
who fails the false belief test lacks a competence, suggesting instead
that the young child's failure with the false belief test should
be accounted for in terms of performance factors (in this connection
see work by Fabricius and Oktay-Gur & Rakoczy). Questions
have been raised about various aspects of the design of the original
false belief test, including questions regarding the way national or
community identity may be thought to play a role in the performance
and understanding of the tasks.



Robert Gordon, Jane Heal and Alvin Goldman propose an alternative to
the theory-theory account of how to understand the attribution of
mental states to others. Heal identifies in theory-theory a scientific
motivation that runs roughshod over important differences between
human beings and the rest of the natural world. While theory-theorists
extend a style of understanding from its application in connection
with the latter to the former, Heal and others propose that we come to
understand what the other persons are thinking "from the
inside", that we "exploit the fact that we are or have
minds" (Heal 1998 [2003: 84]). Heal is particularly concerned
with the question, What further thoughts will a person have given what
thoughts I already know her to have? (Heal (1998) also traces out
further questions about others that may concern us.) Gordon (1986,
1995) insists that simulation theory must be formulated in such a way
as to avoid reliance on both introspection and inference from oneself
to the other. Rather than imagine what I would do in your situation,
he suggests that I imagine being you in your situation. In this way,
thinking about others is taken to parallel understanding of
one's own future behavior: one predicts what one will do by
imagining or pretending that the world is a certain way. Simulation
theory has its roots in *Verstehen* theories favored by
sociologists and historians such as Collingwood and Dilthey (as well
as work by Lipps on empathy; for an overview here see Stueber 2018).
Simulation theory was thought to be given neurophysiological backing
by the discovery of mirror neurons in the pre-motor cortex and in
Broca's area of the human brain that are activated both when an
individual acts and when she observes the actions of another (Gallese
and Goldman 1998; Gallese 2001; Rizzolatti et al. 1996). (For an
overview of the different versions of simulation theory that have been
advocated see Barlassina and Gordon 2017.)


### 3.2 The Second Person and Person Model Theory



Over the years theory-theory and simulation theory have moved closer
towards each other, giving rise to various hybrid accounts of how it
is that we attribute minds to others. But there are those who
challenge both theories and any hybrid versions that they have
spawned. One such challenge arises from Gallagher & Zahavi 2008
who urge that we cast aside both third-person (theory) and
first-person (simulation) approaches, and concentrate instead on
second-person interaction. (In its development in Gallagher's
work, this approach has come to be known as "interaction
theory".) Influenced by work in phenomenology and embodied
cognition, Gallagher and Zahavi propose that our attribution of mental
states to others is the result of perception of and reaction to
behavior understood as expressive of mental life. Furthermore, they
suggest that the activation of mirror neurons be understood as serving
action or response preparation (rather than as supporting simulation,
cf.
 SS3.1).
 Drawing on the work of developmental psychologists such as Meltzoff,
Trevarthen, and Hobson, they identify two forms of intersubjectivity:
a primary form identifiable in early infancy that involves a
differential response to persons and inanimate objects; and a
secondary form when the behavior of persons is interpreted "in
terms of their goals and intentions set in contextualized
situations" (Gallagher & Zahavi 2008: 190). In addition to
primary and secondary intersubjectivity, and at the point when the
child has language, it is suggested that a more nuanced way of
understanding others becomes possible through the development of
communicative and narrative practices (Hutto 2008; Gallagher &
Hutto 2008). Gallagher and Zahavi reject inferential accounts of how
we know others in favor of a direct perceptual one, and they
understand behavior (e.g., gesture, facial expressions, contextualized
actions) to be constitutive of mental life. Importantly, they point
out that one shouldn't conceive of interpersonal understanding
as if it was merely and primarily a question of bridging the gap
between two isolated subjects. Interpersonal understanding occurs in a
context and through "our shared engagement in the common
world" (Gallagher & Zahavi 2008: 190; cf. Gurwitsch 1977
[1979]).



This work aims to move us away from an overly-intellectualized way of
thinking of other minds and to turn our attention to the world that we
live and act in with others. The emphasis here is less on individual
beliefs and desires than in shared intentions and goals. As Gallagher
says in one place, "social cognition is often nothing more than
... social interaction" (2008: 541).



Interaction theory can be seen as an extension of enactivist theories
of perception that understand perception as a highly complex
action-oriented phenomenon, incorporating both meaning and emotion: to
see an object is to see it as affording me opportunity for action, and
this opportunity is taken to be part of how I make sense of the world
and what gives the world value for me (cf. Clarke, Noe, Varela *et
al*). The extension of this idea allows that social interactions
also constitute for me "novel domains of possibilities for sense
making" (De Jaegher 2009). To see the other person is to see her
as affording interaction; in this regard, direct perception is direct
enactive perception. Interactionist theorists have suggested concrete
proposals for empirical work in psychology and neuroscience in the
hopes of moving this research away from what they see as individualism
and methodological solipsism (De Jaegher, DiPaulo, & Gallagher
2010). Rather than taking individual agents to be constitutive of
social interaction, these interaction theorists take them to be
constituted by their interaction with others.



Person model theory challenges theory-theory (TT) and simulation
theory (ST)--as well as interaction theory (IT; Newen 2015, Newen
& Schlicht 2009). Person model theory finds certain limitations in
each of the theories that it opposes. In the place of the two forms of
intersubjectivity recommended by Gallagher and Zahavi, person theory
suggests that the infant works with a "non-conceptual
person-schema" which develops--through the combined work of
observation and narrative--into "conceptualized
person-images". Thus, it is proposed that the understanding of
persons is a step-by-step process of enrichment, central to which is
the acceptance of a multiplicity of strategies (TT, ST, and IT among
them). Which strategy is deployed is dependent upon such things as
context, how similar or different the other is from oneself, whether
the understanding is of an emotion or a propositional attitude, and
the complexity of the mental state. The idea of the deployment of a
multiplicity of strategies is not unique to Person Theory. Gallagher
and Fiebich (2019) argue for what they call a "pluralist
approach" to the understanding of others, drawing on inference,
simulation, direct perception, and/or interaction--depending on
the situation (cf. Nichols & Stich 2003). What this work
highlights is how much may be involved when it comes to understanding
others.



It is possible to see a connection between ideas that are fundamental
to interaction theory (which brings together work from phenomenology
and embodied cognition) and some ideas that can be found in the work
of Stanley Cavell (which aims to interpret and develop the work of
Austin and Wittgenstein, as well as integrating work from
phenomenology with work in analytic philosophy). Where Gallagher and
Zahavi emphasize social interaction, Cavell writes of a duality in the
problem of other minds. Cavell understands this duality to be what the
radical Cartesian sceptic overlooks when she presses her question
about our knowledge of the mind of another. What we must appreciate,
according to Cavell, is that in so far as there is a problem about how
I know you, there is equally a problem about how you know me (herein
lies the duality in the problem). Cavell holds that appreciating this
duality will help us to see the error of the sceptic's ways. The
sceptic considers only one side of the problem and insists that we
suffer from an epistemological lack. Cavell draws attention to the
side of the problem that the sceptic misses and finds in this a fear
on our part of not being understood by another. It is this fear that
gets misunderstood by the sceptic and turned into a darkness which is
projected on to the other. Cavell thinks we must resist this
projection and understand that acknowledgment by another is made
possible by expression on my part. Expression is what makes
acknowledgement possible. We must take responsibility to give
expression to our mental states which can in turn be acknowledged by
others. Importantly, for Cavell acknowledgement is not the same as
knowledge. While the latter is a form of cognition, the forner is to
be understood as behaviour oriented towards another (for more on the
duality that Cavell finds in the problem of other minds see Avramides,
forthcoming). According to Cavell, I must take responsibility for
acknowledging the humanity in others, which acknowledgement is evident
in the way I behave towards them.


## 4. Thinking about Mind Prior to the Twentieth Century


### 4.1 From Descartes to Mill



As so much of the debate concerning others in the heyday of its
discussion in analytic philosophy in the twentieth century can be read
as a reaction to Mill's formulation of the argument from
analogy, it is instructive to consider the context for Mill's
work
 here.[16]
 In proposing his argument, Mill was responding to a challenge laid
down by the eighteenth century philosopher Thomas Reid who argued that
Descartes' philosophy, when traced through the work of
philosophers such as Malebranche, Locke, Hume and Berkeley, leads to
solipsism. In order to avoid this conclusion, Reid argued that
philosophers must jettison the Cartesian framework of ideas and its
trust in reason over the deliverances of sense. According to Reid, the
faculties of reason and perception should be regarded as being on an
equal footing. Rather than insist that all human belief is regulated
by reason, Reid holds that we should allow that our perceptions of the
world are guided by principles for which no proof can be offered.
Amongst the regulative principles Reid identifies there are two
concerning others: (i) there is life and intelligence in our fellow
men; and (ii) certain features of the countenance, sounds of the voice
and gestures of the body indicate certain thoughts and dispositions of
mind (Reid 1785). Mill's work is designed as a defense of the
Cartesian framework in response to Reid's claim that it leads
inexorably to solipsism. According to Mill, all truths are known in
one of two ways: either directly, through the authority of
consciousness, or indirectly, by inference from truths known directly.
Mill believes that knowledge arrived indirectly in this way is
sufficient to avoid the concern of solipsism.



While there is little direct discussion of this question in
Descartes' work, one can find passages devoted to it in
post-Cartesian
 philosophy.[17]
 Malebranche, for example, differentiates knowledge of one's own
mind, of bodies, and of other men's mind: the first is through
consciousness, the second through ideas, and the third through
conjecture (1674-5 [1980: 239]). In the case of another
man's sensations, Malebranche first considers the possibility
that everyone has the same sensations when confronted with the same
objects, but then notes that it can happen that "the internal
fibers of the optic nerve do not produce the same sensation for
different people" (*Ibid*, 66). Despite this possibility,
Malebranche thinks there is reason to believe that God arranged things
so that the same physical conditions do produce the same sensations
(i.e., that nature is uniform). Nonetheless, he argues that we cannot
know another's sensations as there is "a great deal of
diversity in different people's organs of sight as well as of
hearing and taste"
 (*ibid*).[18]
 Writing in response to Malebranche, Arnauld (1683) insists that we do
know other men's minds through ideas: we have ideas of their
bodies and must reason from these to the conclusion that they have
minds. In Arnauld's work we have, arguably, an early formulation
of the argument from analogy.



It may be worth remembering that, in so far as Descartes'
philosophy raises a problem about other minds, it is a thick or
radical sceptical problem. What one finds in Malebranche's work
is a thin sceptical problem. Malebranche appears to take it for
granted that others have minds; what interests him is whether the
sensations that others feel are the same as those that I feel. John
Locke follows Malebrance in not taking seriously the thick or radical
sceptical problem here. Locke asks whether the idea produced in one
man's mind by a violet may not be exactly the same as the idea
produced in another man's mind by a marigold (Locke 1689, II,
xxxii, 15). But as Locke is concerned less with the
"metaphysical Sense of the word Truth" and more with
"the more ordinary Acceptation of those words" he allows
that "the sensible *Ideas*, produced by any Object in
different Men's Minds, are most commonly very near and
undiscernible alike" (Locke 1689, II, XXXii, 13 & 15). 



The threat of solipsism is particularly problematic for the idealism
of George Berkeley. Without proof of other minds, idealism will amount
to nothing but solipsism. Berkeley admits that I cannot have immediate
evidence of the mind of another; what he holds is that there is
"a certain collection of ideas, as directs us to think there is
a distinct principle of thought and motion like until ourselves,
accompanying and represented by it" (Berkeley 1710: Principle
148). While some find in Berkeley's work another early
formulation of the argument from analogy (Urmson 1982), others argue
that his work should be read as putting forwards a causal argument: in
the case of God, I reason that He is the cause or Author of everything
in nature that I see around me; in the case of other finite spirits, I
reason that they are the cause of the movements in the bodies I
observe and the words that I hear (Bennett 1971 and Falkenstein
1990).



Some philosophers also find an argument from analogy in the work of
David Hume, while others interpret his work in a more naturalistic
vein. One thing that cannot be denied is that Hume introduces an
important element into the discussion of others when he writes in
*The Treatise*, "No quality of human nature is more
remarkable, both in itself and in its consequences, than that
propensity we have to sympathize with others" (1738-40
[1888: 316]). It is by means of sympathy that we are affected by the
passions and mental states of others, which otherwise "remain
concealed in the minds of others" (*ibid*, 593).
Precisely how this remarkable capacity operates is a matter of some
debate. There are those who agree with Reid and find Hume unable to
escape the confines of his own mind. These philosophers argue that
Hume recognizes the problem of other minds that arises for the
Cartesian framework that he endorses, and holds that sympathy can do
no more than get us to feel our own feelings in response to what we
observe in the other. But there are others who take Hume to turn his
back on scepticism and the very business of providing reasons for the
belief that others have thoughts and feelings. They read Hume's
work as giving us a psychological account of how it is that we are
able to understand the thoughts and feelings of our fellow men through
the operation of sympathy (Greco 2012; see also work by Waldow
2009).



Hume's understanding of the working of sympathy was challenged
by his contemporary Adam Smith. Smith rejects the idea that I can feel
what another feels. He writes,



> 
> 
> Though our brother is upon the rack, as long as we ourselves are at
> our ease, our senses will never inform us of what he suffers. They
> never did, and never can, carry us beyond our own person, and it is by
> the imagination only that we can form any conception of what are his
> sensations....
> 
> 
> 



A little later he writes,



> 
> 
> That this is the source of our fellow-feeling for the misery of
> others, that it is by changing places in fancy with the sufferer, that
> we come either to conceive or to be affected by what he feels, may be
> demonstrated by many obvious observations, if it should not be thought
> sufficiently evident of itself. (1759: I.i.i.2-3)
> 
> 
> 



With Smith's work we take a step closer to the work of the
simulation theorists of more recent times (cf.
 SS3.1).



It is Reid's contention that, so long as one is working within a
Cartesian framework of ideas, our relations to others must be a taken
to be a matter of probability, hypothesis, or conjecture, and this he
takes to be at odds with the conviction with which, for example, the
child interacts with her nurse. While the Cartesian recognizes only
the solitary operations of mind, Reid proposes that we also recognize
the social operations of mind (Reid 1785 [1969: 71]).


### 4.2 Before Descartes



Philosophers are inclined to trace the problem of other minds back to
the writing of Descartes. If it is true that there is something in
Descartes' philosophy that gives rise to this problem, then one
may expect to find the 'problem of other minds' less
pressing in the work of pre-Cartesian philosophy. With the possible
exception of Augustine (whose work is taken by some to be a pre-cursor
to Descartes'), this is arguably the case.



While philosophers in ancient Greece raise sceptical questions
concerning others, it is has been suggested that the problems they
raise tend to be 'thin' rather than 'thick'
ones (see
 SS1
 and Avramides 2001). Plato and Aristotle, for example, discuss the
value of friendship, but do not ask why we should think others exist
to be friends. Sorabji claims that "it never occurs to Aristotle
to raise doubts about other minds" (1974: 88). According to
Sextus Empiricus, sceptics of the Cyrenaic school raise problems about
the minds of others, but it is not clear that the problem they raise
goes beyond the 'thin' one, How can I know *what*
another thinks and feels? (Tsouna
 1998a).[19]


### 4.3 Another History



While philosophers in the West trace their lineage back to ancient
Greece, it is worth remembering that philosophical ideas were also
being discussed elsewhere in the world. One tradition that has a long
history of concern with issues to do with the minds of others is the
classical Indian tradition. While one should not read texts from other
philosophical traditions only to find parallels with one's own,
it is striking that these early Eastern philosophers may be thought to
have grappled with many of the same issues concerning others as have
philosophers in the Western tradition. It is possible to find
discussion of both epistemological and conceptual problems in
connection with others in these texts. There are two important works
in this tradition devoted to questions concerning others, one by
Dharmakirti in the seventh century and another by Ratnakirti in
the 11th. Indeed, Sharma (1985) writes that
"Dharmakirti is perhaps the first ever thinker to make a
systematic attempt to come to grips with this problem [of other
minds]". Dharmakirti is an idealist who denies the reality
of the external world and whose work, therefore, is open to the charge
of solipsism. In his *Proof of the Existence of Other Streams of
Consciousness*, Dharmakirti first points out that the mind of
another is imperceptible; he then goes on to argue that other minds
are inferred from observed speech and action. Many find in the writing
of Dharmakirti an argument not dissimilar to the one found in the
writing of John Stuart Mill (see, for example, Chakrabarti 2020, Pt.
3) Dharmakirti is careful to acknowledge that there are limits to
our understanding of others (we cannot know what it is like for them)
(Inami 2001). Ganeri (2012) suggests that what we find in
Dharmakirti's text is "a sort of argument from
analogy" for the existence of others. Responding to
Dharmakirti here, Ratnakirti points out the difficulties in
reasoning to the mind of another that one can never be in a position
to verify. In effect, Ratnakirti argues that other minds cannot be
taken to exist, and solipsism must be accepted. However, Ratnakirti is
careful to draw a distinction between conventional and ultimate
existence--while other minds do not exist ultimately, they do
exist conventionally. It is this conventional existence that explains
our actions with regards to others. According to Ganeri, we can also
find in Ratnakirti's work arguments to show that it is not
possible even to form a conception of another mind (2012: 203). This
problem is particularly pressing for the Buddhist philosopher for, as
Ganeri reminds us (2012: 202), without a conception of others it is a
question how one can cultivate compassion.