Revisiting Maher’s one-factor theory of delusion

Today's post is by Chenwei Nie on his recent paper, "Revisiting Maher’s one-factor theory of delusion" (Neuroethics, 2023). Currently, he is a Teaching Fellow in Philosophy at the University of Warwick, UK.

Chenwei Nie

Suppose your friend, Ava, is suffering from a delusional belief that her partner is replaced by an imposter. Despite overwhelming evidence to the contrary - such as the supposed imposter's identical appearance to her partner and knowledge of intimate details, and reassurances from you and her other friends - Ava steadfastly maintains this belief. In this unfortunate circumstance, it is obvious that something must have gone wrong in the formation and maintenance of Ava’s belief. It is likely that Ava would be diagnosed with the Capgras delusion. Unravelling what exactly has gone wrong, however, has proven challenging.

According to a classic one-factor theory of delusion developed by Brendan Arnold Maher (1924-2009), the only factor, i.e. departure from normality, is the patient’s anomalous experience, of which the delusion is a normal explanation. Let us call this sort of anomalous experience the Maherian experience. If this theory is true, then Ava’s belief that her partner is an imposter should be considered as a normal explanation of her particular Maherian experience. Here, ‘normal’ means that if a typical, non-delusional person were to have Ava’s experience, they might also formulate the imposter hypothesis and come to believe that their partner is an imposter.

But is the one-factor theory a satisfactory explanation for delusions? In the past decade or so, a growing number of papers have argued in its favour. My paper, ‘Revisiting Maher’s One-Factor Theory of Delusion’, scrutinizes these one-factor arguments and reveals two fundamental issues.

First, the notion of the Maherian experience is too elusive. For example, advocates of the one-factor theory have been unable to articulate what exactly the Maherian experience is in the Capgras delusion. More often than not, they suggest that the Maherian experience could be an ‘intense’, ‘prolonged’, and ‘profound’ feeling of unfamiliarity. However, these descriptors are not informative enough to tell us why a far-fetched hypothesis like the imposter belief could somehow become a normal explanation.

Second, the notion of normal explanation is overly encompassing. In recognition of the above issue, some supporters of the one-factor theory suggest that suboptimal reasoning might play a part in delusion formation, but they maintain that these suboptimal reasoning processes are still within ‘the normal range’. Yet, without a more tangible account of the Maherian experience, it remains obscure how the reasoning processes that result in delusional explanations are normal.

Unless one-factor theory advocates can adequately address these issues, I think a more promising approach may involve abandoning the idea that the Maherian experience is the only factor in the aetiology of delusion and instead concentrate on searching for additional contributing factors.

Naturalistic understandings of mental disorder can be epistemically empowering

Today's post is by Dan Degerman on his recent paper, "Epistemic injustice, naturalism, and mental disorder: on the epistemic benefits of obscuring social factors" (Synthese, 2023). Dan Degerman is currently a Leverhulme Early Career Fellow in Philosophy at the University of Bristol. 

Dan Degerman

Naturalistic understandings that frame human experiences and differences as biological dysfunctions constitute a major source of epistemic injustice in disease and disability, according to many philosophers.

Epistemic injustice refers to injustices committed against people in their capacity as knowers. This occurs, for example, when someone is disbelieved because of their social identity or when a lack of suitable interpretive resources means that someone cannot make their experiences intelligible to themselves or others. Critics have argued that naturalistic understandings of human experiences and differences can lead to both kinds of epistemic injustice because they tend to obscure the social factors involved in causing those experiences and differences. 

Though such understandings can indeed contribute to epistemic injustice, I think the epistemic benefits they can offer people vulnerable to epistemic injustice have been overlooked.

Consider an apparent exemplar of a naturalistic understanding, namely, the neurobiological understanding of mental disorder. According to that understanding, the key cause of the disorder is some dysfunction in the individual’s brain.

Critics of the neurobiological understanding of mental disorder argue that it prevents people from considering the range of possible factors that might contribute to their often distressing experiences. That is because it decontests the experiences involved, making alternative understandings that focus more on social factors seem irrelevant. Empirical research on what has been called the seductive allure effect of neuroscience indicates the critics are right. But what those critics generally fail to appreciate is that for some people with mental disorder, this is an epistemic feature rather than a bug.

After all, people with psychiatric diagnoses often struggle to get others to take their distress and needs seriously. For instance, participants in a recent ethnographic study by Rebecca Lane recounted how their efforts to discuss their bipolar disorder had been met with trivializing responses. Those responses drew on the contested status and alternative understandings of bipolar disorder to make it appear less serious. As Jake Jackson has argued, such trivialization can constitute and perpetuate epistemic injustices against people diagnosed with mental disorder. 

The decontesting capacity of the neurobiological understanding of mental disorder can help people with psychiatric diagnoses avoid trivialization and associated epistemic injustices. At least, that is what the experiences of some participants in the Lane’s study suggest. For example, one of them said: 

[W]ith bipolar[,] people generally think oh he’s lazy—it’s fashionable—a lot of people get misdiagnosed and you know—but if I say brain disorder and my neurotransmitter[s] don’t do what they’re supposed to… people just leave it like that. (pp. 161-2) 

This person has effectively deployed the neurobiological understanding of bipolar disorder to decontest his suffering and, thereby, avoid epistemic injustice.

Their testimony is not evidence that would-be trivializers abandon their trivializing beliefs when met with a neurobiological understanding of mental disorder. But it is evidence that such an understanding can prevent outright dismissal and that some people with mental disorder value that function highly.

I’m not trying the argue that the neurobiological understanding of mental disorder or naturalistic understandings of disease and disability more generally is unproblematic. Some research shows that people who endorse a neurobiological understanding of mental disorder are more likely than others to endorse stigmatizing claims about people with a psychiatric diagnosis. So we should think carefully about how and when that understanding is deployed.

But, if we are serious about addressing the epistemic injustices that people with psychiatric diagnoses suffer, we cannot simply ignore first-hand testimonies about the value that naturalistic understandings of mental disorder have for those people. Doing so and simply pushing ahead with projects to undermine those understandings risks exacerbating the very problem we are trying to solve.

The experience of dysmenorrhea

Today's post is by Carlota Serrahima on her recent paper, "The experience of dysmenorrhea" (Synthese,  2023). She is a postdoctoral fellow within the ERC funded project "Rethinking Conscious Agency", based at the Universitat de Barcelona.

Carlota Serrahima

My main research topic is the philosophy of bodily awareness, and Manolo Martínez has worked on the philosophy of pain. We were both surprised that, in the literature our work overlaps on, menstrual pain — technically, “dysmenorrhea” — is rarely mentioned. For one of us, dysmenorrhea is the pain most often experienced, and we suspected that this was so for many people. Indeed, according to conservative estimates almost half of menstruators experience dysmenorrhea. That’s probably close to a billion people.

Our paper highlights an important tension: various assumptions operative in the philosophical literature about pain are actually doubtful, or maybe even false, of dysmenorrhea. In the paper we criticize  the model of pain conjured up by those assumptions, which we call the injury-centered model of pain [ICMP], and investigate the phenomenological and functional profile of dysmenorrhea beyond this model.

The first assumption of the ICMP is that pain is primarily a tool for the management of bodily damage. Pain is then adaptive when and because it is a response to such damage. But uterine contractions that expel endometrial tissue during menstruation are part of the correct functioning of the reproductive system, and hence, typically, not damaging. Yet, they are painful in dysmenorrhea. 

This is problematic for mainstream intentionalist views on pain, which would disappointingly deem dysmenorrhea an illusory or misguided pain. Fixing this requires significant elaboration of the intentionalist picture, and in particular of the kind of damage pain is supposed to respond to.

The second assumption is that pains subside as the triggering injury disappears. In other words, injury-centered pains are acute. In fact, dysmenorrhea cannot be readily categorised as either acute nor chronic: it is a cyclical pain, sharing features of both. On the one hand, it occurs in relatively short-lived episodes; on the other, because it recurs, it can result in central sensitisation, as chronic pains do.

We speculate that this temporal profile puts dysmenorrhea in a special position regarding pain catastrophising. First, because its recurrence allows for dysmenorrheic women to get used to the typical unfolding of their pain. Second, because of the widespread, but false, belief that dysmenorrhea is normal. We hypothesize that this broader network of pain-related beliefs will affect the way in which women feel threatened by and catastrophise about dysmenorrhea.

Finally, the ICMP sees pain as an affective kind independent from others, in particular moods. Dysmenorrhea, however, belongs to a class of affective conditions that includes both pain and negative mood intertwined in phenomenologically inextricable ways. Because of this phenomenological profile, and because it is likely that mechanisms underlying pain and mood in dysmenorrhea overlap substantially, the experience of dysmenorrhea is in important respects close to those conditions that fall under the so-called “pain-depression dyad,” such as fibromyalgia.

Anyway, we’ve tried to pay attention to the peculiarities of the lived experience of women, hoping that it will result in a richer understanding of the intricacies of pain, beyond injury management.

Hinge commitments as arational beliefs

Today's post is by Aliosha Barranco Lopez (Bowdoin College) on her recent paper  "Hinge commitments as arational beliefs" (Synthese, 2023).

Aliosha Barranco Lopez

We all have a worldview—an understanding of the world. Our beliefs shape this worldview allowing us to perceive the world as inhabited by mind-independent objects, where concepts like love hold value, gravity governs, etc. One important claim I argue for is that some of our beliefs, which I call hinge commitments, inform our worldview at a fundamental level by providing meaning to the rest of our beliefs in a particular realm.

Let me explain, we all share the belief that there is an external world populated by mind-independent physical objects, which causally produce our experience in much the way we normally suppose. Let’s abbreviate this belief as ‘there is an external world’. This belief is a hinge commitment because it gives meaning to all our perceptual beliefs. 

When I believe that there is a computer in front of me, for example, part of what I believe is that there is a mind independent object—a computer—that is causing a particular perceptual experience in me. If, somehow, I were to lose the hinge commitment that there is an external world (without replacing it), my belief about the computer—along with all my perceptual beliefs—would lose their meaning.

One consequence of this view is that our hinge commitments are arational beliefs, meaning they are neither rational nor irrational. The reason for this is that hinge commitments, given the fundamental role they play in our understanding of experiences (e.g., as perceiving mind-independent objects in the world), determine what counts as empirical evidence for specific propositions.

For instance, the belief that it seems like there is a computer in front of me only counts as evidence for the belief that there is a computer in front of me because I hold the hinge commitment that there is an external world. Without hinge commitments, we would lack a sense of what qualifies as empirical evidence for various propositions. This entails that no evidence can support our hinge commitments because they exist outside the realm of beliefs that can be rationally evaluated. 

One might think that hinge commitments are not beliefs but rather some other mental state. This is because agents who hold them have dispositions to give up their beliefs when they judge that their evidence does not sufficiently support them, but they do not have such dispositions when they judge the same about hinge commitments—think about how philosophers keep believing that there is an external world even after agreeing that we do not have evidence for this belief. 

What I argue is that our beliefs inform our worldview with different degrees of importance. The more important the belief is in our worldview—like our hinge commitments or political beliefs—the harder is to give them up. This diagnosis not only gives us a reason to believe that hinge commitments are beliefs, but it also aligns with how people actually manage their beliefs. 

The resulting view is that hinge commitments are arational beliefs. This view also broadens our understanding of epistemic rationality: some beliefs must be arational for the rest to be either rational or irrational.