In my last post I want to go back to delusions. Isn’t it just hopeless to suggest that they can achieve epistemic innocence? It probably is, as delusions violate all norms of rationality for beliefs we can think of. But it is important to ask whether delusions have any redeeming features.
One aspect I investigated with Matthew Broome, psychiatrist and philosopher, is the capacity people with delusions have to defend their delusional beliefs (see our paper on delusions and reason giving). We start from the premise that irrationality alone cannot offer a demarcation criterion between delusions and ordinary beliefs, for reasons I have already touched on in this blog.
Maybe, we consider, the distinctive mark of delusions is a breakdown of self-knowledge, in that people report beliefs that fit badly with other things they believe (compartmentalisation), are not defended with reasons (lack of authorship), and do not translate into relevant action (double bookkeeping).
It turns out that the three features above are not shared by all delusions, and are not even more common among delusions than among other beliefs. Thus, the aspects of self-knowledge listed above (there are other relevant ones which I left out) cannot provide a satisfactory demarcation between delusional and non-delusional beliefs either. People with delusions argue for their delusions (more or less convincingly), make connections between delusional and non-delusional beliefs, and commit to their delusions not just verbally, but also behaviourally.
The idea that delusions may be psychologically adaptive and play a defensive function is not new. In Butler 2000, the emergence of a delusion following trauma is conceived as an attempt to “confer meaning on otherwise catastrophic loss or emptiness” and temporarily shield the agent from an acute depression which would have interfered with his motivation to get better.
In Roberts 1991 and 1992, adaptive aspects are identified in delusion formation, one of which being the capacity to attribute meaning to experiences: “the novel experience is incorporated within the patient’s conceptual framework, and the occult potential of its unknownness is defused”.
The features of delusions described in Roberts’ work lead Martens 2002 and 2010 to argue that complex delusional systems can be a route to survival and remission via the temporary avoidance of an “unbearable reality”. (For those who are interested in motivational aspects of delusions, Ryan McKay has done very interesting work in this area.)
A few things to notice. The positive roles of delusions described above are not by themselves a reason to believe that having delusions can be epistemically good. At best, they can persuade us that delusions are the lesser of two great evils (the other one being depression) or that they can contribute to a sense of purpose and wellbeing in a similar way as more mundane illusions of self-worth or other self-deceptions.
But what I am wondering is whether there is an epistemic side-effect to the pragmatic benefits that have been explored, and I am intrigued by the thought that, just like confabulatory explanations, delusions may be described as attempts to explain some very unusual experiences whose ‘real’ explanation is somehow unavailable or difficult to grasp. Again, different senses of ‘unavailable’ may apply to the explanation of those experiences leading to the formation of different delusions, and may give rise to different levels of epistemic responsibility.
[I really enjoyed contributing to Brains, reading your comments and having a chance to share some of my thoughts. Thanks to John again for this opportunity.]
Thank you for this thoughtful post. In your opinion, what is the difference between ‘delusion’ and ‘ordinary belief’?
Dear Simone
Thank you for your question, which is a good one and a difficult one to answer.
When I talk about ‘delusions’ and ‘ordinary beliefs’, I refer to a distinction that is standardly accepted. People (not just psychiatrists) tend to distinguish between clinical delusions as a pathological phenomenon and beliefs that may have some of the features of delusions but don’t negatively affect wellbeing in a way that attracts the attention of mental healthcare professionals.
My main point is that we cannot easily identify a demarcation criterion between delusions and other irrational beliefs based on considerations about justification, truth, coherence, self-knowledge, etc. Epistemically, what I see is continuity. I don’t rule out that other considerations may help us identify a more successful demarcation criterion, one that resists obvious counterexamples.
In the book on delusions, in the final chapter, I offer a very tentative diagnosis of the reason why something like Capgras delusion is considered radically different from other irrational beliefs, whereas prejudiced beliefs with no empirical support and no responsiveness to counterevidence are included in the set of ordinary beliefs. My impression is that our different attitude has something to do with familiarity, not with the quality of the irrationality exemplified by the beliefs.
Prejudiced beliefs are (sadly) common and we are used to them. Capgras delusion is not that common and we find it alien and unsettling. But this doesn’t seem to map onto relevant epistemic differences. So the phrase ‘ordinary beliefs’ for me just means ‘beliefs we are used to’ and doesn’t have any other philosophical connotation.
Vilayanur Ramachandran has expressed similar ideas, but I have never found that sort of explanation very appealing. It seems more parsimonious to hypothesize that delusions result from dysfunction of evaluation systems inside the brain. In other words, when we are asked a question, it triggers the execution of a complex brain process whose function is to construct an answer. In people who are delusional, the answer-constructing process does awry and the result that it returns is incorrect.
Hi Bill and thank you for your comment.
I never meant to provide an aetiological characterisation of delusions, and I agree that we need to look for that in the mechanisms inside the brain which are responsible for the evaluation of hypotheses (I’m sympathetic to the two-factor theory of delusion formation).
I was rather thinking about the epistemic status of delusions, and considering the hypothesis that they have some positive effects on the capacity to preserve or acquire knowledge, despite being epistemically faulty themselves in a number of ways. (I think it is unlikely that we can find any generalisable epistemic benefit, but I think it’s a question worth investigating).
I find it plausible that some delusions may have among their causes some motivational factors (e.g. the content of the delusion may be partially determined by what we want to believe), but I don’t think this is plausible for all delusions. I discuss some of this literature in a paper on delusions and self-deception I co-authored with Matteo Mameli, and it’s available here if you are interested: https://www.humanamente.eu/Issues/Issue20.html
Thanks Lisa for the kind response. I see that you were already familiar with Ramachandran’s work. The idea of “reverse Othello syndrome” having a function makes good sense, but I’m far more dubious about the idea of anosognosia having a function. Ultimately of course it’s an empirical question, and everybody is entitled to their intuition about how it will come out. Regards, Bill
Hi Lisa,
I’m sorry to be so late to the discussion, but I’ve been following your posts with interest. I’ve wondered occasionally whether or not confabulation (and perhaps in some cases even delusion) could sometimes carry the genuine rational benefit of increasing the coherence of a body of beliefs, rather than just providing a subject with the illusion of coherence and a positive self-image (which might also be important). While I don’t think coherence trumps truth (in cases where they come apart, and setting aside coherence theories of truth and knowledge, which I don’t endorse), it might be important, as you have mentioned, when it comes to forming intentions and motivating action, and might also help sustain long-term knowledge gathering. In such cases, I can imagine that the drive towards coherence could result in confabulations that have long-term epistemic benefits. Does this sound right to you? Apologies in advance if I’m overlooking any standard views about this issue–I’m quite unfamiliar with this literature, but I’m grateful that your posts have given me a roadmap.
Thank you James, yours is a really interesting suggestion.
In the (scarce) psychiatric and psychological literature about possible benefits of delusion, authors have something like coherence in mind when they highlight the sense of meaning and purpose that people get from a delusional system – as opposed to a single, compartmentalised, delusional belief. Everything fits, everything makes sense. (This explains why delusions can become so entrenched.)
What has not been asked in any detail is what epistemic benefits may come out of this enhanced coherence, and this is definitely a question worth exploring!