A Puzzle about Dementia


Dementia is one of the biggest challenges facing the British NHS, with one in three people developing the disease after the age of 65. This partly explains why there has been such excitement in scientific circles over intravenous immunoglobulin (IVIg), which appears to slow the rate of mental decline in sufferers from Alzheimer’s.

Obviously, from the societal point of view, dementia is a bad thing, and so this news is good. But from the personal point of view, should I be concerned about dementia – at least in its more severe forms? Epicurus famously claimed that we shouldn’t fear death, since when it arrives we won’t be around any more. Many seem to think the same about severe dementia, despite the fact that many – often the same people – also fear such a state.

Here’s how that view might arise. Imagine some extremely unpleasant experience, such as a very painful operation for which anaesthetic is for some reason unavailable. If you’re told you’re about to have such an operation, you will be very afraid, because you think the person under the knife will be you – it is you who will be feeling all that pain. But severe dementia can also be extremely unpleasant, so why isn’t it just like the operation?

There is one big difference. When the surgeon approaches you with her knife, you will have many of the same memories, beliefs, desires, and so on that you have right now. There will be a great deal of what Derek Parfit calls psychological connectedness and continuity between your mental states now and those you’ll have just before the operation. But that isn’t the case with dementia. You will have lost nearly all your memories, and so on. All that will be left is the capacity for conscious experience. And though that conscious experience might be deeply unpleasant, the line of thought goes, that doesn’t matter especially to you, since ‘you’ won’t be around any more, and there will be no important psychological continuity and connectedness between that individual and you now.

My own response to the prospect of dementia, however, is different. I can’t see why it matters very much whether, during the unpleasant experience, I have the same memories, beliefs, and so on that I do now. Consider the painful operation again. It might be so painful that you can’t *think* of anything else while it’s going on – so your memories, beliefs, and so on are entirely inaccessible. Does that somehow make it less bad? What I care about is what will be experienced by the capacity for consciousness I now possess, and if that capacity is going to be exercised in the future in such a way that there is consciousness of seriously unpleasant experiences – whether through some operation, or dementia – that concerns me now whatever memories, beliefs, and so on I am going to have, or indeed lack, in the future.

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7 Responses to A Puzzle about Dementia

  • Jeremy Stangroom says:

    This is a version of the puzzle set by Bernard Williams in his 1970 article “The Self and the Future”, isn’t it?

    I put together an online version of it here:


    I think his view was that it’s possible to pump people’s intuitions in different directions about this sort of thing.

  • Roger Crisp says:

    Thanks, Jeremy. I think that’s right, though of course the puzzle in a sense goes back to Locke et al. Your online analysis is excellent and I look forward to going through it more carefully when I return from hols! One immediate thought: Williams draws a distinction between bodily continuity and mental continuity. My inclination is to think that what matters is continuity of a mental *capacity* (to experience pleasure and pain), a capacity always (in our world, as far as I know) grounded in bodily continuity. So that might make it hard to choose between his options.

  • Anthony Drinkwater says:

    Sorry if this is less lofty than Locke or Williams, but there is another objection to what we might call the «it won’t matter to me» belief.
    Dementia is not solving the Necomb paradox one day and watching the teletubbies the next. The agonising part, for both the  person and their loved ones, is the slow and often intermittent decline from «normality» to dementia. 
    The IWMTM argument might possibly hold for the end point of total dementia, but as it is rare to get there without passing through other stages, I don’t accept it.

  • Roger Crisp says:

    Good point, Anthony. But there might still be a puzzle about the process of degeneration. If the IWMTM belief is right, then we’d expect our present concern about the process to focus particularly on the earlier rather than later stages. but most people seem not to feel like that.

  • eduardo silva says:

    The comparison with an operation is disingenuous; most likely the writer is not assuming an elective operation (which would be postponed until proper anesthesia is available) but one after a trauma experience or a heart attack. You will be told of its need and how unpleasant it will be but also of its need for your survival. Fear rises in anticipation and even if you are properly sedated (but conscious) the pain perception can start well ahead of the surgeon’s knife..

    I fail to see an appropriate comparison with the sensations elicited by dementia. I have lived with four dementia cases and on three of them the pain sensation was not a major ingredient; those seniors (two men one woman all affected on their eighties) were not particularly religious but descended into oblivion in a calm way; one commented jokingly about his forgetfulness – even using the “D” word – until words started failing him. The subject of “death” was discussed freely but no claims to afterlife, with its rewards or penalties were highlighted.
    This slow decline, one described it as a “long good-bye” was perhaps mitigated in these cases by a caring family and judicious management of psychotropics. My conclusion on seeing these three tranquil seniors on their last months was that Dementia can be managed and may not be overlaid with pain and physical stress for the dying person. However, to treat and manage the family and the milieu is a worthwhile endeavour to be pursued regardless of pharmaceutical palliatives or “cures”; let’s go back to Epicurus.

  • George Watson says:

    Suppose it can be shown that babies under the age of one year cannot remember events ( painful or pleasant ),

    yet they still cry out if injured. Would we want to automatically ignore their cries related to short terms pains

    because we have been told they will not remember them ?

    Is someone is sliding into dementia and “seems” to be losing/have lost their ability to create new memories

    should we ignore their cries of pain when treating/dealing with them ?

    A prisoner of the North Vietnamese related that his mind was filled with the pitiful cries of someone being

    terribly tortured and how those howls of pain filled his consciousness to the point that he could not think of

    anything else. After a few minutes he finally realises that those howls were his as he was being hung upside

    down by his arms and then having his whole body pulled against this disjointed arms.

    I don’t presume to know what goes on in the mind of those slipping toward dementia – but better to err on the side

    of compassion and not assume that they have no idea that they are in pain.

  • Roger Crisp says:

    Thanks, both. Eduardo, you’re clearly right that dementia needn’t be distressing. I was imagining a case in which it was, however, so the analogy with a surgical operation is at that point. George, I think I agree with you, though I guess both sides of the debate might agree that the demented know that they are in pain; the question is whether I should care about being demented and in pain later if that later person will not be strongly psychologically connected with the person I now am.