A Davidsonian perspective on psychiatric delusions

Abstract

A number of philosophers have argued that psychiatric delusions threaten Donald Davidson's rationalist account of intentional agency. I argue that a careful look at both Davidson's account and psychiatric delusions shows that, in fact, the two are perfectly compatible. Indeed, a Davidsonian perspective on psychiatric delusions proves remarkably illuminating.

Keywords:

• Donald Davidson
• Intentional Agency
• Psychiatric Delusions
• Rationality

Acknowledgments

I would like to thank three anonymous reviewers, as well as John Campbell, for helpful comments on an earlier draft of this paper. I would also like to thank Simon Evnine, Kirk Ludwig, and Paul Pietroski for helpful discussion on understanding delusions from a Davidsonian perspective.

Notes

Notes

[1] One might think of Davidsonian intentionality on the model of a patterned fabric. Stripes and checks have their identity as such on account of their location within a pattern of stripes and checks. Without such a pattern, there would be no stripes or checks. Similarly, putative thoughts are not thoughts unless they are located within a pattern of thoughts (emotions, intentions, actions) without which there would be no thoughts. As Davidson puts it, thoughts “come only as a matched set” (1982, p. 318).

[2] This is no mere metaphor. Recent empirical studies point to striking neurochemical and neurophysiological similarities between the dreaming brain and the brain of the patient suffering from psychosis (Scarone et al., 2008).

[3] A notable exception is Evnine (1989), who defends a Davidsonian view in the face of psychiatric delusions.

[4] However, Davidson suggests that even in these cases, accusations of irrationality tend to be predicted on the interpreter's detection of patchy incoherence within an otherwise coherent pattern of attitudes and actions (1985/2004, p. 192).

[5] Davidson ends up accommodating irrationality (qua incoherence or inconsistency) by acknowledging the possibility of “perturbations” or “disturbances” within the otherwise coherent patterns constitutive of intentional agency (1985/2004). See section 4 for details.

[6] The Davidsonian might have an answer to this worry. See the four papers on irrationality in Davidson (2004).

[7] There is, of course, evidence of failed correspondence, as the patients’ delusional beliefs are false. However, the patterns in which those delusions are integrated are arguably characterized by a large degree of truth. See note 11 for more on this issue.

[8] For more on this idea see Reimer (2009).

[9] This might help with an understanding of the phenomenon of thought insertion, as the psychiatric patients who suffer from it (those with paranoid schizophrenia) are well-known for their concretized thinking, which includes a tendency to interpret metaphorical concepts literally.

[10] Interesting philosophical questions arise with respect to the delusion of thought insertion. In thought insertion, the patient believes that the thoughts of another have been literally inserted into her head (mind/brain). Such insertion is typically achieved (according to the patient) by magic or technology, perhaps by some sort of diabolical “influencing machine” (Tausk, 1933). A patient who believed that none of his thoughts were his own would be advocating a version of the skeptical hypothesis, tantamount to an “evil demon” or “brain-in-a-vat” hypothesis. This sort of scenario poses potentially challenging questions for the Davidsonian view, on which intentional agency requires that beliefs generally be about their causes. Thanks to an anonymous reviewer for these observations.

[11] Moreover, the fact that Persephone is able to communicate her delusions through shared language arguably guarantees an intentional network characterized by “much truth.” Communication with her therapist about her idiosyncratic delusions would, after all, be impossible unless the two shared some basic (and presumably true) beliefs regarding such things as: the weather, fertility, the Papacy, marriage, body hairs, electronics, aliens, spacecraft, the earth, artificial machines, metals, and atomic numbers.

[12] If Berrios is right, it doesn’t follow that the Davidsonian is right in thinking that disorganized patients are mindless because they are uninterpretable. However, if Berrios is right, disorganized schizophrenia poses no threat to the Davidsonian view that thought is an essentially “patterned” phenomenon.

[13] In contrast, we know why the dog “believes” what she does about the hidden bone's location: dogs tend to be very good at locating bones.

[14] In contrast, the kind of irrationality seen in non-psychiatric cases involving wishful thinking and self-deception does appear to make “conceptual trouble” for Davidson's view, as Davidson himself realizes. For Davidson's treatment of such cases, see his four papers on irrationality (2004).