Dualism is dead! Well, maybe…

I have been struck by how often academics and clinicians writing about functional disorders feel the need to announce the death of dualism – aka mind-body dualism or even Cartesian dualism, depending on the author. It isn’t easy to understand what is meant exactly by this claim and I have been doing a bit of reading between the lines to clarify, at least for myself.

Dualism in philosophy

First, it is worth saying that Descartes understood the mind and body not as radically separate but as in some way highly integrated.  Here he is in the VI Meditation on First Philosophy:

‘Nature also teaches me, by these sensations of pain, hunger, and thirst, that I am not merely present in my body as a sailor is present in a ship, but that I am very closely joined and intermingled with it, so that I and the body form a unit. If this were not so, I, who am nothing other than a thinking thing, would not feel pain when the body was hurt, but would perceive the damage only by intellect, just as a sailor perceives by sight if anything in his ship is broken.’

Or again:

I now understand the mind to be coextensive with the body – the whole mind in the whole body and the whole mind in any of its parts.

Descartes was writing nearly 400 years ago, so it’s not surprising that the terms used in the debate have changed somewhat. Modern philosophy of mind concerns itself, in this context, with the nature of consciousness or intentionality and how subjective experiences are to be explained, and (typically) with the question of how such experiences are related to something physical in the structures and functions of the brain. I think it’s fair to say that philosophers (well, the ones I’ve read) regard the idea that studying the brain can sort this out as bordering on the absurd. Tim Crane for example suggests that in exploring the mind-body relationship we should stop “considering those options which frustrate our understanding of our minds – for example…that we should look for consciousness by inspecting the sticky fatty matter of the brain”. Putting it slightly differently, Galen Strawson comments that even accepting that “…the known phenomena of experience are wholly a matter of the physical nature of ordinary matter under mild conditions (the mild of special conditions that obtain in the brain), … the physics and neurophysiology of the brain don’t enable us to understand how this is so”.

Dualism in clinical thinking

Actually, I don’t think that “dualism” is being used, in the context of clinical writings about functional disorders, in the philosophical sense at all. Rather it refers to the idea that a comprehensive account should include both mind and body mechanisms as expressed here: “A dualistic mind-body understanding of functional neurological disorders (FNDs), also known as conversion disorders, has led to the view that the cause of the symptom should be either psychological (psychogenic) or physical (neurogenic-“organic”).” … “The authors argue that the conversion concept is consistent with recent neuroscientific research findings, and the model allows psychological and neurobiological concepts to be reconciled within a single account of FND that begins to resolve the dualistic mind-body dichotomy.”

In one sense this is not at all a new idea – we have known for a long time that brain states accompany mental states and no doubt this is what Tony David meant when he said that dualism between mind and body “went in the nineteenth century”.

Looking further at this idea…here is an anecdote from the memoir of Geoffrey Keynes, a surgeon who served in the Great War:-

“On one occasion, when I happened to be in my dressing station …. a message came that a gunner had been wounded and was lying beside his gun at the edge of the lake.  Would I, please, come at once?  I then experienced a feeling which it is hard to describe. It was my duty to walk immediately with stretcher-bearers from a position of comparative safety to a gun pit, which was being accurately shelled every few minutes.  I ordered my legs to take me there, but at first they refused to move.  My mind was equal to the ordeal, but another part of my brain declined to pass on the necessary instructions….”

Geoffrey Keynes  The Gates of Memory  1983

Can we describe a mechanism whereby the brain declines to pass on the mind’s instructions? The dualism abolitionists would say – perhaps not perfectly but we’re getting there. I think that’s wrong, and here’s a different vignette to explain why.  Suppose I am crying at a funeral and three friends are discussing my plight. A psychiatric friend says – he has been bereaved (a social state), and he is crying because he is grieving (a mental state).  The neurologist standing next to her says – ah, but he is crying because of activation of a multi-component pathway in the brain that includes the anterior cingulate gyrus.  Wretched dualists! says the third, can you not see that the mental state of grief causes activation of the neural pathway and you need both elements to answer your question? Apart from noting what odd friends I have, you might wonder if my anti-dualism friend is really contributing anything apart from putting the two accounts (psychological and neurological) into the same sentence.

Dualism in clinical discussions

This points to what I take it the end-to-dualism claim actually means in practice: not that we have resolved the mind-body problem nor that we can produce a genuinely unitary account of functional disorders – how could we without solving the mind-body problem?  Instead it means that when we speak about functional disorders we know longer use highly-articulated psychological explanations for what is going on.  We pull this off in one of two ways.

One approach is to drop the psychological altogether or to trivialise or marginalise it. We should understand instead that for functional neurological disorders the problem “lies within the brain and its complex networks” and we should communicate this to patients in ways that enable them to say to themselves “I have a real dysfunction of networks in my brain”. If we use analogies they should be mechanical ones like the computer hardware-software distinction, or other neurological problems like phantom limb.

The other approach is to use a sort of language mash-up, as in a recent review  that summarised studies from neuroimaging, cognitive psychology, biological markers, and epigenetic studies to generate a model that “…allows psychological and neurobiological concepts to be reconciled within a single account of FND that begins to resolve the dualistic mind-body dichotomy”.  This is a (well-meaning) fudge: What happens is that a faux-integrated accounts allows for a misleading impression that the psychological side has been properly worked out because the neural mechanisms associated with it are now better understood.  It would better to say that there are likely psychological mechanisms at play and likely neurological mechanisms, and we don’t understand how the one acts on the other.

Dualism lives – in philosophy, in clinical practice and (hidden in plain sight) in the accounts we offer of functional disorders. Nothing to be embarrassed about, even if some people are made uncomfortable by thinking about psychological causes for illnesses.