Tuesday, 15 June 2021

Ontological and Epistemological Bases of Person Centered Medicine


Person Centred Medicine is a substantial and contentious view of healthcare that carries both ontological and epistemological presuppositions. This chapter examines two key aspects: that the person is a central, basic irreducible element in ontology and that person-level knowledge is both important and possible. Some reasons for holding both of these are sketched.

10 key words

epistemology, normativity, ontology, persons, reductionism, rationality, self, space of reasons


The precise nature of Person Centered Medicine (PCM) is contested. What are its implicit contrasts? Person versus patient or person versus sub-personal body part, for example? What are its essential features? Does it presuppose a specific set of person-level values? Such potential choices and conflicting claims, addressed in other chapters of this book, have consequences for articulating the bases of PCM.

‘Base’ itself suggests two meanings. It may mean the explicit justification or rationale for advancing PCM. Here, I offer a more minimal reading and leave the main work of justification for other chapters. I take the ‘bases’ of PCM to be its presuppositions: specifically, the kinds of ontological and epistemological claims it presupposes to be true. As will become clearer, however, this does offer some partial account of its rationale, too.

I assume that, however its precise nature is articulated, PCM assumes the following broad claims. Ontologically, the level of the person is an irreducible and significant feature of ontology and a proper focus for healthcare. Epistemologically, not only is knowledge of the human person (human beings, people) possible and significant in healthcare, there are also irreducible forms of person-level knowledge which are important to healthcare. A commitment to PCM is thus a substantive commitment to ontological and epistemological claims. I will examine these commitments in turn.


My aim is to clarify the implicit conceptual or philosophical commitments (in ontology and epistemology) of subscribing to PCM. I take it as a premiss that to subscribe to PCM is to assume the genuine existence of persons, for example. A fully worked out account of that commitment might require a completely satisfactory philosophical analysis of ‘person’ and refutation of all rival accounts. But that is an unrealistic account of what is required to support PCM. In this short chapter I will restrict myself to the sort of claims presupposed for PCM. A full philosophical defence of PCM might be possible but would also require narrowing down a precise specification of what PCM is. My aim is more modest but therefore of broader application to a range of views of what PCM involves.

Approaches to fulfil the objectives and knowledge base #1: The ontological presuppositions of PCM

At the very least, PCM presupposes the existence of persons. Further, it assumes that the ‘level’ of the person is important and irreducible in healthcare. That is, truths about persons are not reducible without loss to truths at a more basic level, such as the biochemical functioning of the body and its parts. If such truths were reducible, there would be no need to complement or contrast conventional biomedical approaches with something distinct. PCM would be subsumed by a biomedical view of healthcare.

PCM need not reject the importance of bio-medical medicine so much as complement it. A proper knowledge of the functioning of bodily systems seems to be an essential feature of anything recognisable as general medicine by contrast, for example, with healthcare disciplines that focus solely on specific forms of mental pathology or distress, such as psychotherapy. On the other hand, to count as person centred, PCM must resist the claim that the concept of the person reduces without loss into a set of component bodily systems.

Given the success of modern science in explaining larger systems by decomposing them into the behaviour of smaller scale, simpler systems, what would rationalise the presupposition that the person is a basic feature of ontology and irreducible to smaller scale biology?

One once influential answer – and a helpful illustration here – is provided by Cartesian substance dualism. Descartes’ own account of the bulk of the natural world was that of a mechanical ‘plenum’: a packed world of direct causal pushes and pulls. Responding to the rise of mechanical natural philosophy – corresponding with the rise of modern science – Descartes assumed that mechanical models would apply very generally. At the same time, however, he exempted the mind from this domain. His dualism divides the world into two realms of different sorts of substance: res extensa – the domain of direct causal interaction within a spatial realm – and res cogitans, the non-spatial mental realm. Despite this distinction, the mental realm appears to be modelled on the mechanical philosophy in one sense: mental states are free-standing states, acting as though akin to causal factors [McDowell 1998a: 237-243]. This is one of the features that makes accounting for everyday mental phenomena difficult: for example, the capacity for thoughts to be relational rather than free-standing, about things, to possess ‘intentionality [ibid: 242-3]. If thoughts are free standing items in an inner realm, how can they be about anything, in the outer realm? Another is the problem Descartes himself recognised of accounting for the apparent interaction of the mental and extended realms.

If we put those objections to one side for the moment, however, Cartesian substance dualism would provide a rationale for PCM by explaining one of its presuppositions. Substance dualism implies that persons – possessors of both mental and physical attributes – cannot be entirely made of extended matter. The mental belongs to a distinct non-bodily realm. But subscription to what now seems an outmoded approach to the mind would be a high price to pay for subscribing to PCM. So if not that, why else might one take the concept of the person to be irreducible?

One lesson of academic philosophy of mind since the 1970s is that there are many (apparently or epistemically) possible models of the relation of mind and body [Fulford et al 2006: 653]. At one end of a spectrum is substance dualism. At the other is eliminativism: the view that there are no mental states because the mental is a failed theory of the physical and should be eliminiated. Between are varieties of forms of property dualism, more or less closely tethered by supervenience (an asymmetric relation of dependence), and reductionist physicalism (the view that the mental can be reduced without loss to physical descriptions). Thus, a commitment to PCM requires a rejection of eliminativism and reductionist physicalism but leaves open a variety of other ontological positions. But what might motivate that choice however precisely it might be realised?

Within analytic philosophy of mind, two main lines of argument have been stressed. One concerns the irreducibility of the qualitative aspects of mental states and experiences: their qualia. One such argument is Frank Jackson’s thought experiment concerning Mary the neuroscientist, locked in a black and white room but knowing the full physics and neurophysiology of colour vision [Jackson 1986]. Surely, runs the line of thought, she learns something new when presented for the first time with a red object? But if so, there is at least one fact to be learnt – what red looks like to the conscious mind – that cannot be captured within physical and neurophysiological theory. So reductionism of the mental to the physical is false.

A second line of argument, associated with Donald Davidson, concerns the irreducibility of the structure of rationality to mere lawlike relations between natural events [Davidson 1980: 229-44]. On the twin assumptions that the mental is essentially tied to rationality, and that rationality cannot be codified into any structure of laws and hence captured in physical theory, then the mental is irreducible to physical properties.

Such arguments – or the premises of such arguments however precisely formalised: the appeal to qualia or to rationality – supply plausible motivations for subscribing to a view of the irreducibility of the mental to something physical of bodily. But that is not yet to say that the notion of a person is specifically of importance. What of the centrality of the person?

There is a line of thought in philosophy dating back to David Hume which would motivate scepticism about its importance, even while conceding the importance of the mental. Hume presents an argument that focuses on the nature of the self as something mental able to unify (mental) experiences as the experiences of a particular subject. Hume suggests that an introspective search for such a self, as the subject of thoughts and experiences, yields nothing.

For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe anything but the perception. . . . If anyone, upon serious and unprejudiced reflection, thinks he has a different notion of himself, I must confess I can reason no longer with him. All I can allow him is, that he may be in the right as well as I, and that we are essentially different in this particular. He may, perhaps, perceive something simple and continued, which he calls himself; though I am certain there is no such principle in me. [Hume 1978: 252]

Hume’s final comment is clearly meant to be ironic. Introspection, Hume suggests, reveals nothing that could stand in the sort of relation to one’s mental states that a self is supposed to do. This leads him to advocate a minimalist ‘bundle theory’ of mind. The self is identified simply with the mental states encountered in introspection and not with an ego which stands in some ownership relation to them. Philosophers since Hume have adopted a variety of responses that concede the basic point. Daniel Dennett argues that the self is an abstraction: a narrative structure of mental states. ‘A self is also an abstract object, a theorist’s fiction.’ [Dennett 1992]. Others have denied the existence of self in favour of underlying neurological structures [Hofstadter 2007; Metzinger 2003; Taylor 1999]

There is, however, a conflicting line of thought dating back to Kant that grants an important basic status to the person. The philosopher Peter Strawson offers an explicitly Kantian account [Strawson 1959, 1966]. To earn the right to the idea that experiences are unified as the experiences of a particular subject (a person), there has to be some way to specify or identify that subject. Without some such criteria, the idea of a single subject is vacuous. But as Hume’s description of introspection reveals, conscious experience does not yield any criteria to identify a subject (or owner) for one’s experiences. It reveals only the experiences themselves. From this, Hume concludes that there is no substantial self. But there are criteria for the identification of a subject available elsewhere: third-person criteria for the ascription of experiences to fellow human beings on the basis of what they say and do.

Strawson suggests that these can provide substance to the idea of a self even though they are not appealed to in self-ascriptions of experiences. This is because, while self-ascription of experiences is made without any appeal to these (or any other) criteria to identify a subject, it is still made in accord with them. As Strawson puts it, ‘The links between criterionless self-ascription and empirical criteria of subject-identity are not in practice severed’ [Strawson 1966: 165]. Thus, it is because we are identifiable from a third person perspective as embodied subjects located within the world that we can also self-ascribe experiences without appeal to, but still in accord with, those criteria. The third-person criteria substantiate the idea of a subject.

Strawson goes on to argue that the person is a basic feature of ontology. Persons have, essentially, both physical and mental predicates. It is this combination that underpins the kind of subjective perspective to which Hume appeals but which cannot, by itself, constitute a self. As the contemporary philosopher John McDowell puts it:

The alternative [to a purely mental construal of the self as subject of experience] is to leave in place the idea that continuity of “consciousness” constitutes awareness of an identity through time, but reject the assumption that that fact needs to be provided for within a self-contained conception of the continuity of “consciousness”. On the contrary, we can say: continuous “consciousness” is intelligible (even “from within”) only as a subjective angle on something that has more to it than the subjective angle reveals, namely the career of an objective continuant with which the subject of the continuous “consciousness” identifies itself. The subjective angle does not contain within itself any analogue of keeping track of something, but its content can nevertheless intelligibly involve a stable continuing reference, of a first person kind; this is thanks to its being situated in a wider context, which provides for an understanding that the persisting referent is also a third person, something whose career is a substantially traceable continuity in the objective world. [McDowell 1998b: 363]

I do not wish to suggest, in this brief chapter, that a Kantian account of the nature of the person and a Strawsonian justification of its ontologically basic status is a necessary presupposition of PCM. But it provides a worked example of the kind of account to which PCM is committed: to the existence and importance of persons as a basic feature in ontology.

Approaches to fulfil the objectives and knowledge base #2: The epistemological presuppositions of PCM

Just as PCM presupposes that the person is a proper part of ontology – an irreducible level of description of the natural world – so it also carries epistemic presuppositions. Centrally, it is possible to have knowledge of persons. To clarify this point, think of the more normal English plural. It is possible to have knowledge of people. Well of course it is! But a biomedical perspective that explicitly rejected the principles of PCM would still claim knowledge of the bodies, of their functions and dysfunctions, of people. Thus, to arrive at a presupposition that marks PCM out as a distinct substantive and potentially contentious approach, it is necessary to say something more. It is not just that knowledge of persons is possible, for example, of their bodies, but that knowledge of persons or people as persons is possible. What might be the characteristic content of such person-specific knowledge?

The previous section, however, mentioned one way to substantiate just such a claim. Descriptions of mental phenomena answer to a distinct constitutive principle that ‘finds no echo in physical theory’: the Constitutive Ideal of Rationality [Davidson 1980: 223]. To adopt a different metaphor: even without subscribing to a dualism of substances (mental and physical), one might still recognise a distinction between two conceptual spaces or modes of intelligibility: the space of reasons and the realm of law [Sellars 1997]. The former has application at the level of the person and captures a normative or evaluative character in the assessment of reasons for belief or action. One of the features that mark out persons or people from other objects of scientific scrutiny is that people, unlike planets or atoms, act for reasons or motives or to further goals or interests and they can be successful or fail in the attempt. This introduces a normative dimension – a dimension of correctness or incorrectness, good or bad – that is missing from basic physical sciences. Thus, part of the way in which PCM earns the right to claim a sui generis level of knowledge of persons as persons is to commit to the importance and irreducibility of placing subjects in the ‘logical space of reasons’.

This link opens up connections to other areas often taken to be part of PCM when less minimally approached. (Recall that this chapter has adopted a minimal approach to what PCM requires in order to explore the central ontological and epistemological presuppositions of any plausible view of PCM.) The space of reasons is also the space of values. Thus, any version of PCM that argues for the moral and ethical consequences or presuppositions of treating patients as persons will have to trade in this space: the space of evaluating the Good and the True.

But while sketching the logical space of knowledge of persons as persons helps show the nature of the ambition for PCM it does not address one specific worry that, while philosophically-influenced, can occur in reflective moments inspired by everyday life. It is the worry that, desirable that knowledge of other people – as persons – is, it is strictly impossible. One can never achieve good enough evidence to justify claims about another’s mental life. Such is the worry. Here is a way to seem – misleadingly! – to ground it. Consider again the Cartesian substance dualist picture of the relation of mind and body. If mind and body occupy different dimensions – the physically extended and the thinking – then it seems that no form of perception based on causal receptivity in the physical realm can yield awareness of other minds because minds are simply not in that realm. How therefore is knowledge of others as persons so much as possible? Surely one can never bridge the gap between one’s own experience of another person and their actual thoughts and feelings? This worry then seems to float free of the specifically Cartesian dualist background. Even if the mind is software running on the hardware of brains – as philosophical functionalism claims – how is it possible to infer from someone’s behaviour to their underlying software state?

During the last 30 years, there have been two dominant philosophical answers to this question. One approach argues that such knowledge is akin to scientific theoretically mediated knowledge of unobservable entities: ‘theory theory’ [Davies and Stone 1995a]. Its main rival starts from the idea of empathic projection: one imaginatively places oneself in the position of the other and imagines one’s thoughts and experiences: ‘simulation theory’ [Davies and Stone 1995b]. It is worth noting in practice how unsatisfactory either is to ground the idea that one can ever have genuine knowledge of how another person – a patient or service user or even a loved one, perhaps – is feeling. We do not seem to know the theory presupposed by the former approach while the act of imagination outlined by the second seems inadequate for knowledge.

PCM need presuppose no particular account of how person-level knowledge of persons as persons is possible. Its commitment is not to any specific explanation of how but to the more generic claim that it is possible. However, it is worth noting that the very idea that there is a problem to be solved may be more philosophical – albeit longstanding – artefact than common sense.

A helpful alternative view stems from the same account of the basic role of persons highlighted in the previous section which is both essentially mental and physical. If one starts from that perspective, rather than the dualistic separation of mind and body, then there is no need to deny the common-sense idea that human minds can express themselves in human behaviour and hence be known by others through that expressive behaviour. This contrasts with the ‘alienated’ conception of our relation to others that underpins a Cartesian view of human bodies where bodies are brute machines at best merely controlled by minds that inhabit a different dimension. On the non-Cartesian picture, one can have a form of almost direct knowledge of another’s mental states. It is direct knowledge of the expression of the mental state. As John McDowell argues, experience of other people is not limited to their bare behaviour, with mentality hidden behind it. The idea of almost direct knowledge can be applied:

in at least some cases of knowledge that someone else is in an “inner” state, on the basis of experience of what he says and does. Here we might think of what is directly available to experience in some such terms as “his giving expression to his being in that ‘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 in the sense I explained. (McDowell 1998a.: 387)

Although one person’s inner states do not themselves fall within the direct perceptual experience of another person (hence ‘almost’), the fact that they express them can. This idea of 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 meaning and expression.

One way to think about this alternative to the Cartesian picture is to think about how one might describe another person’s smile. We naturally reach for apparently epistemically risky and mind-presupposing words over the supposedly more basic purely physical descriptions. A smile is relaxed, ecstatic, forced, brave etc. Such descriptions are easier to offer than the purely geometric and non-mental descriptions that the Cartesian picture of the relation of others’ bodies and minds would suggest.

This particular philosophical ‘diagnosis’ of the implicit error behind the thought that it can seem that direct person-level knowledge is impossible provides one rationale for thinking that epistemological strand of PCM is fully justifiable. But it is not necessary to accept this to subscribe to PCM. The epistemological mark of PCM is merely that there is an available form of knowledge, couched at the level of the person, that is a key component of healthcare alongside more basic knowledge of bodily functions and dysfunctions.

Practical Implications

The practical implications of adopting a PCM approach will be explored more directly in other chapters of this book. The purpose of this conceptual and theoretical chapter is to clarity the presuppositions and suggest the logical space for such a distinctive view. Only if some things are ruled out by it does PCM have any content. I have argued that what is ruled out is the idea that person-level claims can be reduced without loss to lower level bio-medical claims and that there is no distinctive person-level knowledge. I have also offered a brief route map to escape the pessimistic thought that it is simply impossible to have knowledge of other people’s mental states.

But some practical implications are immediately apparent. If person level knowledge exists and is irreducible and assuming that it is important to healthcare (a claim for which I have not offered argument here for reasons of space but is apparent elsewhere in this book) then the pursuit of person level knowledge requires the right kind of inquiring stance. Since the most obvious way to find out how things stand with another person is to ask them, and to listen to what they say, and to watch what they do, then these forms of inquiry must be available in doctor-patient, or specialist-client, or practitioner-service user relations.

Discussion and conclusions

Person Centred Medicine is a substantial and contentious view within the philosophy and practice of healthcare. The mark of its substance is that it rules some things out. It is incompatible with some other views of nature and hence healthcare. In this chapter, I have explored its main broad presuppositions concerning ontology and epistemology. Its commitment to the existence of the person as a basic and irreducible element within ontology stands in opposition to views that deny that by, for example, promising to reduce the concept of the person to more basic phenomena. Thus, it stands opposed to various reductionist views. Its commitment to there being a form of person level knowledge and it being achievable stands in opposition both to claims that there is no such irreducible level or sceptical claims that it is impossible to attain. Although advocates for PCM need not have a fully worked out philosophy of the person or person-level knowledge, I have sketched the nature of this sort of commitment and made some suggestions for how they might be supported.


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