Tuesday 24 April 2018

A New Defence of Doxasticism about Delusions

Today's post is by Peter Clutton is a graduate student at the Australian National University School of Philosophy (previously at Macquarie University) working on the nature and taxonomy of delusions.

In my recent article, "A new defence of doxasticism about delusions: The cognitive phenomenological defence", I enter the ongoing debate over whether delusions are beliefs (or whether they are some other, non-doxastic state). I argue that delusions are beliefs, despite the many objections to that view.

It might seem obvious that delusions are beliefs. People with delusions typically insist they believe what they say, and the fact that they do is often the very reason they come to clinical attention in the first place. Indeed, clinical manuals like the DSM define “delusion” as a type of “false belief”.

On the other hand, delusions seem to defy many preconceptions about the nature of belief. For example, we expect people to act on their beliefs, but people with delusions do not always act in expected ways: people with the Capgras delusion insist that their spouse has been replaced by an imposter, and yet they often continue to live with the supposed imposter, and do not to report their “real” spouse missing.

I argue that delusions really are beliefs, despite the fact that they violate these preconceptions about beliefs. I defend what I refer to as a “cognitive phenomenological” account of belief (based on the work of Kriegel), and argue that on this view, delusions are beliefs. On this view, beliefs are defined by the type of experience they involve. When I consider the proposition “snow is white”, for instance, I experience a certain kind of mental assent towards the proposition. That is what it is to believe that snow is white.

There are a number of reasons to suppose that people with delusions do indeed experience this kind of mental assent towards the propositions they assert. Evidence of this can be found in clinical reports and interviews, as well as in the cognitive scientific work on delusions. All of this evidence suggests that people with delusions have the same, familiar experience of mental assent we all do to the propositions we believe.

I go on to provide reasons for preferring my defence of delusions as beliefs over other defences in the literature. For example, in the most thorough work on this topic, it has been convincingly argued that delusions are similar in kind to beliefs, and that they can be interpreted as such. However, I argue that my defence represents a stronger fit with the impressive range of cognitive scientific work on delusions.

I conclude by considering a final objection. Many researchers have argued that people with delusions undergo a radical change in their overall experience of the world, and that this renders their delusions totally unlike typical beliefs. I suggest that this line of thought ought to be explored further, and that in fact my own view might be compatible with it: perhaps patients do undergo such experiential change, and yet continue to mentally assent to their delusions in the typical manner.


  1. Do you think Schreber experienced the familiar phenomenology of mental assent to a proposition? He described his experience as "miracled up" and " all this naturally in my own imagination". Louis Sass short book is excellent on the nature of the experience involved. Or Alexander's Capgras patient who said " it feels like there is something wrong. It feels like i am telling a story" . This doesn't show they didn't believe their delusions of course but the phenomenology doesn't look like familiar doxastic phenomenology

    1. Thanks very much for your comment. I think what you say touches on a really important area for delusions, specifically the phenomenology of delusions, one that ought to be investigated further.

      In the paper, I address the question you raise, with reference to the work of Sass and others. There I draw a distinction between narrow and wide views of experience, and say that while delusions do seem to often involve radical phenomenological shifts in wider world-experience, that might still be compatible with people having the more narrowly described judgement experience I discuss in the paper. It seems plausible to me that at least some of the descriptions you point to might be accounted for in this way: the people you mention might still assent to those propositions, but this experience is itself embedded in larger alterations in their overall experience of the world, which is what shows through in their first-person descriptions.

      However, this is an empirical thesis, and it may also be that some people with delusions just do not have the experience I describe. Some of the descriptions you point to make a plausible case for this---they at least raise the question. As I say in the paper, I think that evidence points to delusions in general fitting the pattern I describe, but there are open questions about what to say in some cases. If these cases really are exceptions, that also raises some definitional and taxonomic questions (i.e, if delusions are defined as some kind of belief, and I think beliefs involve the phenomenology I describe, what do I say about the purported exceptions?). All of this deserves further exploration.

      I’d be interested to hear your thoughts on all this.

      Thanks again,


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