I realise that these draft papers are rather a dull use of a blog but it is why I started it originally.
Abstract
The two main psychiatric taxonomies set out codifications
of psychiatric diagnoses via lists of symptoms with the aim of maximising the
reliability of diagnostic judgements. This approach has been criticised,
however, for failing to capture the precise connection between diagnostic
judgements and symptoms as detected by skilled clinicians. Assuming that this
criticism is correct, this chapter offers related two accounts of why this
might be so. First, skilled diagnostic judgement may be an exercise of tacit
knowledge: a practical skill the exercise of which requires the presence of the
patient or client. Second, the conception of criteria implicit in DSM and ICD
is based on a mistaken view of how what people say and do connects to their
mental states. On an alternative account, in an overall gestalt diagnostic
judgement the various criteria are abstractions from a whole which directly
expresses the underlying psychopathological state of patients or clients.
Introduction
For the last 50 years, both of the major psychiatric diagnostic
systems – DSM and ICD – have aimed at reliability at the potential cost of validity.
They have done this by codifying diagnosis in the form of criteria, influenced by
operationalism from the philosophy of physics and down playing aetiological theory.
It is an empirical question whether DSM-III, -IV and now -5 and the parallel ICD
classifications have achieved this aim overall.
There have been criticisms, however, that the explicit criteria
under-determine the diagnoses made by skilled clinicians. That is, the criteria
themselves have a vagueness or indeterminacy for which experienced psychiatrists
have to compensate in diagnostic judgements in response to particular patients expressing
particular signs and symptoms. The overall top-down or gestalt judgement is more
precise than the component criteria on which it is supposed to be based.
The aim of this chapter is not to address whether this is so
but rather how it could be so. In doing so, I will make two suggestions. First,
diagnosis may involve an important tacit element. As a recognitional judgement,
it may share characteristics of an uncodifiable form of know-how. Second, the postulation
of criteriological intermediaries between the skilled clinician and their patients’
or clients’ actual conditions may distort the recognitional process. Judgement of
the underlying mental states of patients and clients may be more secure than the
operationalised criteria.
The first section outlines the reasons for the emphasis,
since the second half of the twentieth century, on operationalism in both the
main psychiatric taxonomies. The second section sets out three similar clinically
based criticisms of the resulting criteriological model of diagnosis.
The final two sections set out to shed light on how this
might possible first by suggesting that diagnositic judgements are an instance
of a broader class of tacit knowledge and then by suggesting that the
criteriological view distorts the way that clinical signs and symptoms bespeak,
to a skilled clinical, underlying pathologies directly.
Background: the rise
of criteriological diagnosis
Over the last half century, there has been a concerted effort
to improve the reliability of psychiatric diagnosis by pruning the two main diagnostic
systems of possibly over hasty aetiological theory and stressing instead more directly
observational features of presenting subjects. Two main factors explain this.
(For a fuller account, see [Fulford et al 2005].)
First, on its foundation in 1945, the World Health Organisation
set about establishing an International Classification of Diseases (ICD). The chapters
of the classification dealing with physical illnesses were well received but the
psychiatric section was not widely adopted. The British psychiatrist Erwin Stengel
was asked to propose a basis for a more acceptable classification. Stengel chaired
a session at an American Psychological Association conference of 1959 at which the
philosopher Carl Hempel spoke. As a result of Hempel’s paper (and an intervention
by the psychiatrist Sir Aubrey Lewis) Stengel proposed that attempts at a classification
based on theories of the causes of mental disorder should be given up (because such
theories were premature), and suggested that it should instead rely on what could
be directly observed, that is, symptoms.
In fact, Hempel’s paper provided only partial support for the moral that was actually drawn for psychiatry.
He argued that:
Broadly speaking, the vocabulary of science has two basic functions:
first, to permit an adequate description of the things and events that are the objects
of scientific investigation; second, to permit the establishment of general laws
or theories by means of which particular events may be explained and predicted and
thus scientifically understood; for to understand a phenomenon scientifically is
to show that it occurs in accordance with general laws or theoretical principles.
[Hempel 1994: 317]
These two requirements – that terms employed in classifications
should have clear, public criteria of application and should lend themselves to
the formulation of general laws – correspond to the aims of reliability and validity respectively. Clear public criteria promote both
test-retest and inter-rater reliability whilst general laws are a step, at
least, towards construct validity. But it was the former that was adopted by psychiatry
as the key aim at the time. With respect to it, Hempel claims that
Science aims at knowledge that is objective in the sense of being intersubjectively certifiable, independently
of individual opinion or preference, on the basis of data obtainable by suitable
experiments or observations. This requires that the terms used in formulating scientific
statements have clearly specified meanings and be understood in the same sense by
all those who use them. [ibid: 318]
He commends the use of operational definitions (following Bridgman’s
book The Logic of Modern Physics [Bridgman
1927]), although he emphasises that in psychiatry the kind of measurement operations
in terms of which concepts would be defined would have to be construed loosely.
This view has been influential up to the present WHO psychiatric taxonomy in ICD-10.
The second reason for the emphasis on reliability and hence
operationalism was a parallel influence within American psychiatry on drafting DSM-III.
Whilst DSM-I and DSM-II had drawn heavily on psychoanalytic theoretical terms, the
committee charged with drawing up DSM-III drew on the work of a group of psychiatrists
from Washington University of St Louis. Responding in part to research that had
revealed significant differences in diagnostic practices between different psychiatrists,
the ‘St Louis group’, led by John Feighner, published operationalised criteria for
psychiatric diagnosis. The DSM-III task force replaced reference to Freudian aetiological
theory with more observational criteria.
This stress on operationalism has had an effect on the way
that criteriological diagnosis is codified in DSM and ICD manuals. Syndromes are
described and characterised in terms of disjunctions and conjunctions of symptoms.
The symptoms are described in ways influenced by operationalism and with as little
aetiological theory as possible. (That they are neither strictly operationally defined
nor strictly aetiologically theory free is not relevant here.) Thus one can think
of such a manual as providing guidance for, or a justification of, a diagnosis of
a specific syndrome. Presented with an individual, the diagnosis of a specific syndrome
is justified because he or she has enough of the relevant symptoms, which can be,
as closely as possible, ‘read off’ from their presentation. The underlying
syndrome is connected to more accessible, epistemologically basic signs and
symptoms.
An objection to criteriological
approaches
Although the rationale
for a criteriological, or bottom up, approach to diagnosis seems clear, it has not
escaped criticism. The charge outlined in this section is that combining individual
signs and symptoms understood initially in isolation from context and only assembled
in the conjunctions that add to diagnosis is makes the signs and symptoms
imprecise.
In a paper called
‘Phenomenological and criteriological diagnosis: different or complementary?’ Alfred
Kraus, professor of psychiatry at Heidelberg, argues that diagnostic systems such
as DSM and ICD miss out an important element of psychiatric diagnosis [Kraus
1994]. Because they assume that diagnoses are built up from a number of individual
and conceptually independent symptoms they cannot capture top-down and holistic
elements of diagnosis.
One key criticism
that Kraus makes of what he calls this criteriological approach to diagnosis, is
that rather than providing a reliable foundation, the connection between individual
symptoms and conditions lacks specificity.
[S]ymptomatological/criteriological
diagnosis not only makes the reality of the patient accessible in a very
reduced way but also portrays the pathological phenomena in a very imprecise
and broad manner…
The reduction of phenomena to symptoms and criteria has as its consequence a
loss of specificity. [ibid: 153-4]
Taking
delusions as an example of a symptom, on the criteriological model, for
schizophrenia, Kraus argues that there is not a reliable connection between
delusions in general and schizophrenia. ‘Delusion’ is a vague term picking out
a variety of psychological states. The reliable connection is between particular
kinds of delusional structure and schizophrenia. But the identification of delusions
with a specific schizophrenic colouring presupposes, Kraus argues, a top down
holistic model rather than a bottom up description. The assumption on the criteriological
approach that symptoms can be recognised and described independently of the
psychopathological diagnostic categories of which they are a part introduces
vagueness to their descriptions and hence undermines the specificity of their
connection to diagnostic judgements.
Kraus also argues
that in the bottom-up model, symptoms can only be added together through conjunction.
But no mere conjunction of individual symptoms—a ‘Chinese restaurant menu’ approach—can
capture the psychological integrity up to which the individual parts add. For that,
one again needs a top down holistic approach. This is not to say, however, that
particular elements cannot be identified in a holistic diagnosis. It is just that
the individual elements have a different logic.
One way of marking
this distinction (although not Kraus’ own) is to contrast parts that are independent
pieces and parts that are essential aspects. The pieces of a jigsaw add up to a
whole, but each piece can exist independently of the others. By contrast a musical
note has both a tone and a pitch, but neither aspect can exist independently of
the other. Thus, according to a holistic approach, psychological symptoms are
not independent building blocks towards diagnostic judgements but are interdependent
aspects of a psychological unity.
Kraus combines
with these two comments on the limits of a criteriological model of diagnosis with
a further philosophical explanation of the difference in approach. This is why he
contrasts the criteriological with a phenomenological rather than merely a holistic
model. This concentrates not on psychiatric diseases but on the mode of being of
whole persons, the ‘whole of the being in the world of schizophrenics or manics’.
Thus the phenomenologically based diagnosis of schizophrenia turns on an overall
assessment of the patient—a ‘praecox feeling’—as having a very different form of
‘being-in-the-world’. Whether or not that more general view is correct, Kraus’
criticism suggests that the operational structure of psychiatric manuals introduces
a vagueness into the description of symptoms and hence undermines the
specificity of the link between symptom, when properly understood, and
diagnostic judgement.
Mario Maj makes a similar criticism. Again taking the example
of schizophrenia, he argues that:
One could argue that we have come to a critical point in which it is
difficult to discern whether the operational approach is disclosing the intrinsic
weakness of the concept of schizophrenia (showing that the schizophrenic syndrome
does not have a character and can be defined only by exclusion) or whether the case
of schizophrenia is bringing to light the intrinsic limitations of the operational
approach (showing that this approach is unable to convey the clinical flavour of
such a complex syndrome). In other terms, there may be, beyond the individual phenomena,
a ‘psychological whole’ (Jaspers, 1963) in schizophrenia, that the operational approach
fails to grasp, or such a psychological whole may simply be an illusion, that the
operational approach unveils. [Maj 1998: 459-60]
In fact, Maj argues that this shows the weakness of the
operational approach. He argues that the DSM criteria fail to account for aspects
of a proper grasp of schizophrenia: for example, the intuitive ranking of symptoms
(which have equal footing in the DSM account). He suggests that there is, nevertheless,
no particular danger in the use of DSM criteria by skilled, expert clinicians for
whom it serves merely as a reminder of a more complex prior understanding. But there
is a problem in its use to encode the diagnosis for those without such an additional
underlying understanding:
If the few words composing the DSM-IV definition will probably evoke,
in the mind of expert clinicians, the complex picture that they have learnt to recognise
along the years, the same cannot be expected for students and residents. [ibid:
460]
Maj’s criticism that the DSM criteria do not capture a proper,
expert understanding of the diagnosis of schizophrenia raises the question of how
or why that could be the case. If the criticism is right, is it that the wrong criteria
have been used: either the wrong symptoms and / or the wrong rules of combination?
Or is there something more fundamentally wrong with the criteriological approach
as applied to psychiatry?
Josef Parnas suggests the latter. In a paper describing pre-operational
approaches to taxonomy and diagnosis as a ‘disappearing heritage’ he comments on
an underlying difference in attitude towards signs and symptoms of schizophrenia.
When the pre-DSM-III psychopathologists emphasized this or that feature
as being very characteristic of schizophrenia, they did not use the concept of a
symptom/sign as it is being used today in the operational approach. This latter
approach envisages the symptoms and signs as being (ideally) third person data,
namely as reified (thing-like), mutually independent (atomic) entities, devoid of
meaning and therefore appropriate for context-independent definitions and unproblematic
assessments. It is as if the symptom/sign and its causal substrate were assumed
to exhibit the same descriptive nature: both are spatio-temporally delimited objects,
ie, things. In this paradigm, the symptoms and signs have no intrinsic sense or
meaning. They are almost entirely referring, ie, pointing to the underlying abnormalities
of anatomo-physiological substrate. This scheme of ‘symptoms = causal referents’ is automatically activated
in the mind of a physician confronting a medical somatic illness. Yet the psychiatrist,
who confronts his ‘psychiatric object’, finds himself in a situation without analogue
in the somatic medicine. The psychiatrist does not confront a leg, an abdomen, not
a thing, but a person, ie, broadly speaking, another embodied consciousness. What
the patient manifests is not isolated symptoms/ signs with referring functions but
rather certain wholes of mutually implicative, interpenetrating experiences, feelings,
beliefs, expressions, and actions, all permeated by biographical detail. [Parnas
2011: 1126]
The claim here is that the criteriological approach has the
wrong model of psychiatric symptoms and signs in two respects. Just as smoke can
indicate fire or tree rings the age of a tree, the criteriological approach takes
signs and symptoms to be free standing items which merely causally indicate underlying
states. Furthermore, these relations are independent of one another: they are atomic.
By contrast, Parnas suggests, psychiatric signs and symptoms are both essentially
meaning-laden rather than brutely causal and also mutually interdependent wholes.
It is the latter claim, which plays the more important role in his criticism.
One argument for their interdependence is that it is only in
particular contexts that symptoms are reliable. Thus, for example, mumbling speech
is comparatively widespread (Parnas estimates 5% of the population) but in – and
only in – the context of other features such as ‘mannerist allure, inappropriate
affect, and vagueness of thought, it acquires a psychopathological significance’
[ibid: 1126]. So the effectiveness of the sign is context-dependent. In some contexts
it is indicative and in others not. Excluded from context – as it is in the criteriological
context – it is vague. But it is precise in context. Parnas goes further by suggesting
a more than merely additive view. Grasp of psychiatric symptoms is likened to seeing
the figure of the duck-rabbit first as a rabbit and then suddenly as a duck: seeing
the signs and symptoms under an overall aspect or gestalt.
A Gestalt is a salient unity or organization of phenomenal aspects.
This unity emerges from the relations between component features (part-whole relations)
but cannot be reduced to their simple aggregate (whole is more than the sum of its
parts)... A Gestalt instantiates a certain generality of type (eg, this patient
is typical of a category X), but this typicality is always modified, because it
is necessarily embodied in a particular, concrete individual, thus deforming the
ideal clarity of type (universal and particular). [ibid: 1126]
So the model of diagnosis is one in which the skilled clinician
grasps the right diagnosis as an integrated whole in which different aspects can
be seen as abstractions from that whole rather than as its basic building blocks.
Such a view would accommodate Kraus’ rejection of a ‘Chinese restaurant menu’ approach
and Maj’s suggestion that criteriological elements serve as reminders for already
skilled clinicians. They do – on this view – in the sense that, after the fact,
such articulations of the overall picture are possible, as a musical note may be
divided into its pitch, tone and duration whilst it cannot be built up from those
as independent building blocks. But that does not imply that the expert judgement
of the whole could be built up from the individual criteria understood in isolation.
There is a
further possibility hinted at in the criticism of Kraus, Maj and Parnas. On a criteriological
view symptoms are not merely independent of each other (as Kraus points out)
they are conceptually independent of the underlying psychopathological state
that they indicate. But in the case of Kraus and Parnas, at least, there is a
suggestion that the connection between symptoms (when correctly understood) and
psychopathological state is more direct: the state is expressed directly in the
signs and symptoms to those, at least, with the skill to see it.
Diagnosis and tacit
knowledge
The criticisms
of the criteriological approach set out in the preceding section prompt two further
questions. The bottom up codification of diagnosis through simpler, more basic signs
and symptoms suggests an explanation of how complex diagnostic judgement is possible.
It is possible because it is based on simpler more epistemically accessible building
blocks. The first question concerns the nature of an overall ‘gestalt’ judgement
if that explanation is rejected. On what is top-down judgement based and what is
its relationship to the criteriological approach? In this section, I will suggest
an analogy with context-dependent tacit knowledge to try to make the rejection
of the above explanation seem a less puzzling possibility [for a more detailed
discussion see Thornton 2013]. But it will also help highlight how the move from
context-dependent recognition to explicit criteria introduces vagueness into the
description of psychiatric symptoms.
Second, if diagnostic
judgement is not based on more observational features of a clinical encounter, how
can it yield knowledge of underlying mental states? In the final section, I will
suggest an analogy with the more general ‘problem of other minds’ and outline what
may initially seem a counter-intuitive view outlined by the philosopher John McDowell
which inverts the epistemic priority of judgements about behavioural signs and symptoms
and judgements of underlying mental states. Again it will suggest that reliance
on basic criteria comes at the cost of introducing vagueness into description
of psychiatric symptoms which undermines the potential directness of
psychiatric diagnosis as described by Kraus, Maj and Parnas.
I suggested at the start that the development of the theoretically
minimal criteriological approach to diagnosis in psychiatry was partly influenced
by operationalism in the philosophy of science in the first part of the twentieth
century. The aim was to minimise uncodified elements in psychiatric diagnosis so
as to maximise reliability. But there was, in the second half of the century, a
contrasting view about the nature of scientific knowledge: the chemist turned philosopher
Michael Polanyi’s arguments for the importance of tacit knowledge. (Polanyi himself
talks of tacit knowing rather than knowledge.
I will, nevertheless, use ‘knowledge’ whilst talking about his views but will return
to emphasise the practical dimension to what is tacit.) Top-down or gestalt judgement
in psychiatry can be thought of as an instance of tacit knowledge. I will use
Polanyi to introduce this notion but will deviate from his account shortly.
Polanyi gives the following example:
We know a person’s face, and can recognize it among a thousand, indeed among
a million. Yet we usually cannot tell how we recognize a face we know. So most of
this knowledge cannot be put into words. [Polanyi 1967b: 4]
This is an instance of what he takes to be a general phenomenon.
Indeed, he begins his book The Tacit Dimension
with the following bold claim:
I shall reconsider human knowledge by starting from the fact that we can know more than we can tell. [Polanyi
1967b: 4]
The broad suggestion is that knowledge can
be tacit when it is, on some understanding, ‘untellable’. ‘Tellable’ knowledge is
a subset of all knowledge and excludes tacit knowledge. But the slogan is gnomic.
Does it carry, for example, a sotto voce qualification ‘at any one particular time’?
Or does it mean: ever?
The very idea of tacit knowledge presents a challenge: it has to be tacit
and it has to be knowledge. But it is not easy to meet both conditions. Emphasising
the tacit status, threatens the idea that there is something known. Articulating
a knowable content, that which is known by the possessor of tacit knowledge, risks
making it explicit. There is a second strand through Polanyi’s work which helps
address this problem. At the start of his book Personal Knowledge in which he says:
I regard knowing as an active comprehension of things known, an action
that requires skill. [Polanyi 1958: vii]
These two features suggest a way to understand tacit knowledge:
it is not, or perhaps cannot be made, explicit and it is connected to action, the
practical knowledge of a skilled agent. The latter connection suggests a way in
which tacit knowledge can have a content: as practical knowledge of how to do something.
Taking tacit knowledge to be practical suggests one way in which it is untellable.
It cannot be made explicit except in context-dependent practical demonstrations.
It is not that it is mysteriously ineffable but that it cannot be put into words
alone.
Psychiatric
diagnostic judgement can be thought of as an example of such a skill: the
ability to recognise, in a particular
context, the manifestation of psychiatric illness. Polanyi also compares
recognition to a practical skill, likening it to bicycle riding:
I may ride a bicycle and say nothing, or pick out my macintosh among
twenty others and say nothing. Though I cannot say clearly how I ride a bicycle
nor how I recognise my macintosh (for I don’t know it clearly), yet this will not
prevent me from saying that I know how to ride a bicycle and how to recognise my
macintosh. For I know that I know how to do such things, though I know the particulars
of what I know only in an instrumental manner and am focally quite ignorant of them.
[ibid: 88]
In both cases,
the ‘knowledge-how’ depends on something which is not explicit: the details of
the act of bike riding or raincoat recognition. Whilst one can recognise one’s
own macintosh one is, according to Polanyi, ignorant, in some sense, of how.
Thus how one recognises it is tacit. Polanyi suggests here that
explicit recognition of something as an instance of a type is based on the
implicit recognition of subsidiary properties of which one is focally ignorant.
He explains the distinction of focal and subsidiary awareness using the example
of focusing attention on what a pointing finger points to. In looking from the
finger to the object, the object is the focus of attention whilst the finger,
though seen, is not attended to. It is not invisible, however, and could itself
become the object of focal attention.
Polanyi seems to assume that
the question of how one recognises something always has an informative answer
and then to cover cases where it is not obvious what this is he suggests it can
be tacit. But, firstly, whilst it sometimes may have an informative answer,
there is no reason to think that it always has (cf recognising that a wall is
red). Secondly, even in cases where one recognises a particular as an instance
of a general kind in virtue of some further properties and cannot give an
independent account of those properties, it is not clear that one need be
focally ignorant of them. It may be, instead, that the awareness one has of the
‘subsidiary’ properties is simply manifested in the act of recognition. I might
say, I recognise that this is a, or perhaps my, macintosh because of how it
looks here with the interplay of sleeve, shoulder and colour even if I
could not recognise a separated sleeve, shoulder or paint colour sample as of
the same type. Whilst it seems plausible that one might not be able to say in
context-independent terms just what it is about the sleeve that distinguishes a
or my macintosh from any other kind of raincoat (one may, for example, lack the
vocabulary of fashion or tailoring) that need not imply that one is focally
ignorant of, or not attending to, just those features that make a difference.
Recognition may depend on context-dependent or demonstrative elements, such as
recognising shapes or colours for which one has no prior name. But if anything,
that suggests one has to be focally aware, not focally ignorant, of them.
Thus
Polanyi’s own account of the tacit nature of recognition faces objections. But
such criticism suggests the possibility of a more minimal account of tacit
knowledge. Recognition is tacit because it is a skill – for example, developed
through repetition and critical practice and demonstrated in applications – and
because it can thus be articulated only in context-dependent terms such as
‘like this!’. It cannot be explicated in words alone independently of
additional practical demonstrations in context.
If the skilled
diagnostic judgement described in the previous section by Kraus, Maj and Parnas
is thought of as tacit knowledge as just explicated then it can be contrasted with
criteriological diagnosis in the following way. The criteria set out in ICD and
DSM are an attempt to make psychiatric diagnosis explicit, to put it into words alone. They attempt to set out context-independent
descriptions of psychiatric syndromes.
Such an
attempt is akin to attempting to model an ability to recognise colours and
shades on general knowledge of the names for colours that ordinary people have.
For most people, the ability to recognise, think about and recall (at least for
some period) particular shades of colour goes beyond what they can make
explicit linguistically. The ability can instead be manifested by pointing to
particular instances of colour themselves. By contrast with the fine
discriminations that can be made in the presence of actual colours and shades,
colour vocabulary is generally vague.
Similarly, by
contrast with the context depending discriminations of skilled clinicians made
in the presence of their patients and clients, the criteria set out in
diagnostic manuals are vague. Because they are fully linguistic, the criteria
in DSM and ICD are portable. There is an advantage in communication of a
linguistic codification of diagnosis that floats free of particular inter-personal
relations. But it is bought at the cost of precision. By contrast, the features
that play a role in the top-down diagnoses of skilled clinicians are identified
in the presence of a particular patient’s or client’s psychological whole. Such
recognition cannot be captured in words alone.
The analogy
suggested in this section has been between clinical judgement made possible by
the presence of a patient or client and recognition of a macintosh, either as
an instance of a kind or as a particular one, or recognition of a colour or
shade in its presence. The analogy suggests that the patient herself is passive
and plays no active role. Since clinical judgement depends a great deal on what
patients say and do, the general picture of tacit knowledge needs augmenting
with a specific account of the recognition of mental states. That is the
subject of the next section.
Criteria
and other minds
In the previous
section, I suggested that tacit knowledge can be used to shed light on the idea
that an overall top down or gestalt diagnostic judgement could be more specific
than a diagnosis based on general but vague criteria. A skilled clinician has a
recognitional skill which can only be exemplified in context-dependent judgements
in the presence of patients or clients. That is to approach the problem from an
epistemological perspective: what it is to have knowledge in this way. In this section,
I will complement that by taking an ontological view. What could the relation be
between the underlying mental states and conditions amounting to mental illness
or disease syndromes and the more apparently epistemically accessible criteria set
out in DSM and ICD? Addressing this question will also address the active role
of patients and clients raised just now.
To sketch
an answer to this question I will consider a debate from the philosophy of mind
about whether our knowledge of other minds in general is based on behavioural criteria. Although the argument against
that view that I will outline does not directly carry over to the case of
psychiatric diagnosis, it does suggest why criteriological diagnosis is vague
compared to top-down or gestalt judgement.
The
concept of a criterion was introduced into the philosophy of mind as a solution
to the problem of other minds by followers of the philosopher Ludwig Wittgenstein.
The influential Wittgenstein exegete PMS Hacker, writing in the Oxford Companion
to Philosophy, defines a criterion thus:
A standard by which to judge something;
a feature of a thing by which it can be judged to be thus and so. In the writings
of the later Wittgenstein it is used as a quasi-technical term. Typically, something
counts as a criterion for another thing if it is necessarily good evidence for it.
Unlike inductive evidence, criterial support is determined by convention and is
partly constitutive of the meaning of the expression for whose application it is
a criterion. Unlike entailment, criterial support is characteristically defeasible.
Wittgenstein argued that behavioural expressions of the ‘inner’, e.g. groaning or
crying out in pain, are neither inductive evidence for the mental (Cartesianism),
nor do they entail the instantiation of the relevant mental term (behaviourism),
but are defeasible criteria for its application. [Honderich 1995]
Key
features of this definition are that the criteria of, for example, an ‘inner’ state
like pain are fixed by convention and are partly constitutive of what we mean by
the word ‘pain’. Thus groaning and crying out are not mere symptoms but rather part
of what we understand by ‘pain’, connected by definition not induction. At the same
time, however, the criteria of pain are defeasible.
The
reason for this qualification is the following intuition. Whilst, in general, pain
behaviour is the expression of underlying pain, on occasion behaviour which resembles
pain behaviour in every detail is not the expression of pain. It may be the result
of acting or pretence. (And equally, genuine underlying pain may sometimes be stoically
kept from expression.) As a result, the criterial support that apparent pain behaviour
gives for a judgement that someone is in pain is taken to be defeasible. It can,
on occasion, be overturned.
The
idea that criteria give only defeasible support for a claim is combined with a further
assumption which the philosopher John McDowell, in his criticism of this very notion,
describes thus: ‘if a condition is ever a criterion for a claim, then any condition
of that type constitutes a criterion for that claim, or one suitably related to
it’ [McDowell 1982: 462-3]. In other words, criteria are types. Whilst on most occasions,
when instances of some general type of criterion are satisfied the underlying fact
for which those instances are criteria also obtains, on some occasions the type
of criterion is satisfied (by some particular circumstances) but the fact does not
obtain. In such cases, the criterion is satisfied but is nevertheless also defeated.
This
suggests that there is an essential underdeterminination in the support that criteria,
so understood, provide for judgements about mental states. In any particular case,
on this picture, some expression, some sign or symptom of pain for example, may
or may not actually mean that the person
expressing it is actually in pain. Hence the behavioural expression is vague.
Its meaning is imprecise.
This
worry provides the basis for McDowell’s criticism of the use of criteria, understood
in this way, to explain how knowledge of other minds is possible. On the assumption
that it is sometimes, at least, possible to know someone else’s mental state, McDowell
asks how such knowledge is supposed to be based ‘on an experiential intake that
falls short of the fact known... in the sense [of]... being compatible with there
being no such fact’ [McDowell 1982: 459].
The
worry is this. If one knows something, then it cannot be the case that - ‘for all
one knows’ - things may be otherwise. That possibility is ruled out precisely because
one knows what is the case. But if criteria fall short of implying the fact
that they are supposed to enable one to know, then they cannot themselves rule out
the possibility that the fact does not obtain. So if our everyday concept of knowledge
does rule this out then such knowledge cannot be based on perception that
the criteria for some mental state are satisfied. A possible alternative view in
which the perceived the criteria is supposed merely to be enough to satisfy linguistic
conventions for the ascription of knowledge would also not address
this objection, either.
If experiencing the satisfaction of
‘criteria’ does legitimise (‘criterially’) a claim to know that things are thus
and so, it cannot also be legitimate to admit that the position is one in which,
for all one knows, things may be otherwise. But the difficulty is to see how the
fact that “criteria” are defeasible can be prevented from compelling that admission;
in which case we can conclude, by contraposition, that experiencing the satisfaction
of ‘criteria’ cannot legitimize a claim of knowledge. How can appeal to “convention”
somehow drive a wedge between accepting that everything that one has is compatible
with things not being so, on the one hand, and admitting that one does not know
that things are so, on the other? [McDowell 1982: 458]
Imagine
that there are two observers who both see that the behavioural criteria, so construed,
for two other people being in pain are satisfied but that only one of them
really is in pain: the other is pretending. If the observers’ experiences are the
only grounds for them knowing the mental state of their respective subject and if
their perceptions are the same in both cases (seeing that the criteria for pain
are met) then how can one observer know their subject’s mental state and the other
observer not? Surely, neither has knowledge
even if one has, by chance, a true belief. It seems merely a matter of luck that
one observers’ experience is of undefeated criteria whilst the other’s is of defeated
criteria, that in one case the observed subject really is in pain and in the other
merely pretending. The luckier observer has done nothing extra to earn the right
to knowledge. Construing criteria as defeasible to try to accommodate the fact
that we are fallible at knowing other people’s minds cannot work because it
rules out that we ever have knowledge.
There
is, however, an alternative view of criteria and of knowledge of other minds based
on them. Rather than assuming that, in the case of pretence, the criteria for mental
states are satisfied but are also defeated - by the fact that it is a case of pretence
- one can instead construe it as a case of the criteria only appearing to
be satisfied. This is a rejection of the idea that criteria are defeasible types
of situation. Instead, McDowell presses the idea that, when criteria are satisfied,
one’s experience does not fall short of the facts. So there cannot be cases
where the criteria are satisfied without the fact for which they give criterial
support also holding.
McDowell supports this interpretative
possibility by considering a passage in which Wittgenstein discusses criteria in
a non-mental context.
The fluctuation in grammar between
criteria and symptoms makes it look as if there were nothing at all but symptoms.
We say, for example: “Experience teaches that there is rain when the barometer falls,
but it also teaches that there is rain when we have certain sensations of wet and
cold, or such-and-such visual impressions.” In defence of this one says that these
sense-impressions can deceive us. But here one fails to reflect that the fact that
the false appearance is precisely one of rain is founded on a definition. [Wittgenstein
1953 §354]
Wittgenstein rejects the temptation
to say that both the fall of a barometer and also sensations of wet and cold (or
visual impressions) are mere symptoms of rain. Instead, and by contrast with
the barometer fall, the connection between the sensations (or the visual impressions)
and rain is definitional or criterial. They are used in an explanation of what ‘rain’
means. This thought can, however, be interpreted in two ways.
Commentators often take this to imply
that when our senses deceive us, criteria for rain are satisfied, although no rain
is falling. But what the passage says is surely just this: for things, say, to look
a certain way to us is, as a matter of ‘definition’ (or ‘convention’... ), for it
to look to us as though it is raining; it would be a mistake to suppose that the
‘sense-impressions’ yield the judgement that it is raining merely symptomatically
- that arriving at the judgement is mediated by an empirical theory. That is quite
compatible with this thought... when our “sense-impressions” deceive us, the fact
is not that criteria for rain are satisfied but that they appear to be satisfied.
[McDowell 1982:466]
Someone
who steps outside their house when the lawn sprinklers are switched on may think
that by having experiences of wet and cold they have experienced the criteria for
rain, albeit on this occasion defeated. After all, when being taught about rain
they may have been taught it through practical definitions involving experiences
that felt similar. But the experiences used in the practical definition were not
just any experiences of wet and cold but wet and cold experiences of rain falling.
Similarly in the case of criteria for mental states, pretence can make it seem
that the criteria for pain, for example, are satisfied when, in fact, they are not.
Taking
the criteria to be merely any experience
of wet and cold (for rain) or any experience
of high pitched cries (for pain) makes them too vague to sustain knowledge. Correcting
this requires rethinking the generality and the descriptive nature of criteria.
If the criteria for pain are given in general and behavioural terms, they are too
vague to underpin knowledge. Such ‘criteria’ do not only mean pain. So one might think of them as particular though still behavioural.
If so, only particular instances of behavioural criteria (particular instances of
crying out and rubbing knees etc) are valid guides to underlying pain. Such a suggestion
maintains the behavioural character of criteria for mental states but denies their
generality. But this threatens the idea that one can learn how to recognise
pain. The alternative is to maintain (something of) their generality but deny the
restriction to merely behavioural signs and symptoms. On such an account, the criteria
for pain do not have in common anything that could be given in mind-free behavioural
terms. Rather they share the essentially mind-involving generality of being expressions of pain.
McDowell
offers a philosophical diagnosis of why such a view of criteria seems to go unnoticed
which goes back to the influence of Cartesian dualism. If one starts from that basic
picture then it invites a contrast between the behavioural states of other people
to which one can have direct perceptual access, and mental states, which are, in
some sense, hidden behind them. According to Descartes, they even exist in different
kinds of space (res cogitans and res extensa). Cartesian dualism suggests an
alienated picture of human behaviour in which all that anyone else can ever see
is bodily movement which is
only contingently associated with minds. Because perception of, and judgements about,
such ‘behaviour’ is taken to be unproblematic whilst access to other people’s mental
states is taken to be problematic, a route is needed from one to the other. Thus
it seems plausible to think that judgements about mental states have to be
grounded in independent judgements about behaviour. The alienated picture of human
behaviour survives in approaches to the philosophy of mind which have long since
rejected Descartes’ conception of the mind as res cogitans (or thinking stuff) existing
in a different dimension to matter (res extensa).
This
picture of the relation of mind and body is neither obligatory nor natural, however.
One can instead think of mind and body as more closely linked. What one says and
does expresses what one thinks and feels.
Whilst one person’s mental states do not themselves fall within the direct experience
of another their expression of their mental state does. Such expression is not
one that is consistent with the absence of the inner state. So McDowell replaces
an account in which all that is visible to an observer is another person’s intrinsically
brute or meaningless behaviour, standing in need of further interpretation and hypothesis,
with one in which that behaviour is charged with expression.
This
claim addresses the worry raised at the end of the previous section that an
analogy with a tacit recognitional judgement of a macintosh or a shade of
colour suggests that patients and clients are passive in the face of a clinical
gaze. If the analogy held closely then one person’s mental state would have to
fall directly within the experience of another just as a colour can. The nuanced
view is that this is not so. Patients and clients have to reveal their mental
states through speech and action. But, to continue to describe the nuanced
view, what they say and do makes their mental lives available to others in a
way that requires no inference. This accounts adds to the more general picture
of tacit knowledge in the previous section the further idea that recognitional
judgement of others’ mental states requires that the other people actively
express them.
By denying
that our ‘access’ to the minds of others must proceed through a neutrally described
behavioural intermediary (their behaviour), McDowell can offer a much less technically
charged account of criteria which he summarises thus:
I think we should understand criteria
to be, in the first instance, ways of telling how things are, of the sort specified
by “On the basis of what he says and does” or “By how things look”; and we should
take it that knowledge that a criterion for a claim is actually satisfied - if we
allow ourselves to speak in those terms as well - would be an exercise of the very
capacity we speak of when we say that one can tell, on the basis of such-and-such
criteria, whether things are as the claim would represent them as being. [McDowell
1982: 470-1]
Knowledge
of other minds depends on what people say and do. It does not require a kind of
direct mind reading. The judgement is based on, emerges from, what they say and
do. But the conceptualisation of what they say and do need not be couched in mind-independent
neutral terms. As Dowell comments:
This flouts an idea we are prone to
find natural, that a basis for a judgement must be something on which we have firmer
cognitive purchase than we do on the judgement itself; but although the idea can
seem natural, it is an illusion to suppose it is compulsory. [McDowell 1982: 471]
It
may be easier to see patterns and generalities in behaviour construed as
essentially expressive of minds than in neutrally described bodily movement. So
even though judgements about others’ minds may be based on their behaviour, the
description of the behaviour may be less secure than the description of what it
expresses.
I have
set out two contrasting accounts of criteria from the philosophical discussion of
the problem of other minds to shed light on the more specific issue of mental illness
diagnosis. There are, however, two related important differences between the two
cases which need mention.
First,
the application of the idea of criteria in the more general problem of other minds
and in the case of psychiatric diagnosis differ in one clear respect. It is merely
a theoretical idea in the former case but set out in practical detail in recent
editions of the DSM and ICD in the latter case. Second, and related to this, is
an important difference in the dialectical context of criticism of behavioural criteria
in the two cases. The argument above assumes that it is possible to have knowledge
of other minds. Since the standard model of criteria (as defeasible behavioural
types) makes knowledge impossible, it cannot be the basis of our knowledge of other
minds.
But
one might object that psychiatry does not aspire to knowledge when it comes to diagnosis but some weaker state such as a
belief with a particular degree of probability. And hence an argument which
shows that knowledge cannot be based on criteria, so understood, need not
undermine that project. Such an objection carries risk, however. Since psychiatry
is a practical discipline, diagnoses form the basis for action (concerning treatment
and management). Thus clinicians need more than merely having beliefs with a particular
(suitably high) probability of being true, they need to know that they do.
Nevertheless,
even if psychiatric diagnosis need not aspire to knowledge itself but merely to
some known probability of being correct, it could be based on criteria
understood as behavioural types (ie the target of the criticism of this
section). Providing that there are other methods of arriving at diagnoses, such
as the considered judgement of skilled clinicians or longitudinal studies, it would
be possible to make an assessment of the sensitivity and specificity – in probabilistic
terms – of types of behavioural criteria. The dialectical context differs for defenders
of defeasible criteria for knowledge of other minds because they assume that there
is no more fundamental way of having such knowledge and hence no independent test
of the construct validity of the criteria.
Despite
these differences, McDowell’s discussion of the two accounts of criteria and the
role, in the account he defends, of the idea that behaviour can be more than mere
behaviour but rather expressive mental states sheds light on the possibility, at
least, of the relative vagueness of criteriological diagnosis compared to the specificity
of gestalt judgement. Both the DSM and ICD stress operationalised descriptions as
opposed to more essentially psychiatric descriptions couched in aetiological terms.
They do this in an attempt to provide secure foundations for diagnosis. But that
very strategy makes the criteria mere approximations of the underlying psychopathological
states they aim to capture. As Kraus, Maj and Parnas suggest, precision requires
thinking of psychiatric symptoms as abstractions from a diagnostic whole rather
than built up from neutral – or more neutral – criteria whose obtaining does not
strictly imply the presence of the psychiatric syndrome for which they are supposed
to be signs.
An
alternative view of diagnostic criteria, drawing on McDowell’s account and
influenced by the empirical claims of Kraus, Maj and Parnas would stress the
specific schizophrenic colouring of particular delusions, for example. It may
seem that this carries the risk that identifying that a patient or client is
experiencing such a delusion is riskier than the vaguer claim that they are
experiencing some sort of delusion or other. But this may not be so in context.
In particular cases, the justification for thinking that the delusion carries a
specific schizophrenic colouring may be what warrants the more general claim
that they are thus experiencing some more general category of delusion.
This
view also helps address a suggestion in Kraus’ and Parnas’ description
mentioned earlier: that the connection between symptoms and psychopathological state is more
direct than a mere evidential or causally indicating relation. The state is
expressed directly in signs and symptoms to those, at least, with the skill to
see it. On the view developed above, skilled clinicians do not merely infer the
diagnostic state of their patients and clients from signs and symptoms that are
independent of or distinct from them. Rather, they see (or hear) in what their
patients say and do the expression of a diagnostic condition.
It is natural to object to such a view (as the editors of this book did)
that clinicians are fallible beings, too and so the shortcoming of the
criteriological approach cannot be that criteria do not strictly imply the
presence of what they are criteria for. But on the view sketched, this
objection presupposes the wrong account of the fallibility of such judgements. If
criteria for mental illnesses were both general and defeasible, that would
explain how knowledge claims could fail but it would also fail to explain how
knowledge is ever possible. On the alternative view sketched above, when all
goes well a skilled clinician is able to respond to the expressions of, say,
schizophrenia which do indeed necessitate that the patient has schizophrenia.
Fallibilism is explained by the fact that some apparent criteria for
schizophrenia are not in fact such criteria. But it is a mistake to assume that
the best that even a skilled clinician can rely on is a description of the
signs and symptoms that merely indicates that it is likely that someone has
that syndrome. Skilled judgement is more precise than the vague descriptions of
symptoms found in the DSM.
Conclusions
I have
considered the charge made against criteriological models of diagnosis that, compared
with the gestalt judgement of a skilled clinician, criteriological descriptions
of symptoms are essentially vague. I have argued that two independently plausible
considerations help explain how this could be so. Epistemologically, diagnosis based
on gestalt judgement could be akin to the kind of context-dependent practical skill
that underpins one model of tacit knowledge. Such skill resists codification in
general context-independent terms akin to the DSM and ICD’s diagnostic criteria
but is nevertheless a form of conceptually structured knowledge. Ontologically,
the diagnostic criteria of the DSM and ICD may be merely more or less behavioural
abstractions from underlying psychological reality. Skilled clinicians need not
rely on neutral criteria but on the direct expression of complex psychological wholes.
Acknowledgement
This
chapter was written whilst a fellow of the Institute for Advanced Study, University
of Durham. My thanks both to the IAS, Durham and the University of Central Lancashire
for granting me research leave.
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