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The Nature of Clinical Delusions
Certain features of clinical delusions defy explanation. Delusions are unresponsive to evidence. For example, those suffering from the Capgras delusion might claim that a loved one has been replaced with an imposter; no amount of argument can shake them from this conviction. Delusional individuals tend not to act on their delusions and tend not to update beliefs in response to their delusions. For example, an individual might claim their food is poisoned while simultaneously eating it. Delusional individuals also often seem to recognize which of their beliefs are delusional; they appear to be aware, in some sense, of the way the world actually is. They might speak of a difference between "delusional and non-delusional realities." What theory of cognitive architecture can explain these features? In my dissertation, I present and defend a model of the delusional mind.
Cognitive Feelings and Epistemic Emotions
When describing mental states with phenomenal content, philosophers often fall back upon a familiar few types: visual and other sensory experiences, pains, itches, emotions, etc. These do a poor job of entirely cataloging our phenomenology. A category of experiences that is discussed less often is picked out by the ordinary term "feelings." Consider the way that your neighborhood feels familiar to you now but did not when you moved in. This feeling of familiarity is an example of a cognitive feeling. Other examples include the feeling of understanding, the feeling of invincibility, the feeling of puzzlement, or the feeling of confidence. What sort of role do cognitive feelings play in our cognitive economy? Are they emotions? Do we form beliefs on the basis of feelings, and should we?
The ordinary concept of belief is likely what Ned Block calls a "mongrel concept": a concept that picks out various dissimilar cognitive states. For instance, the ordinary concept of memory denotes a number of very different mental processes, such as working memory, semantic memory, and episodic memory. We should expect that theories of belief will become similarly fragmented. We also might find a need to posit mental states that are like beliefs in some respects but not others. I am interested in investigating proposals for various belief-like attitudes, such as Jonathan Cohen's acceptances, Keith Frankish's superbeliefs, and Tamar Gendler's aliefs. I am particularly interested in relating this literature to the psychological literature on dual processing and on implicit attitudes, and in using novel attitudes to explain psychiatric phenomena such as delusions, obsessions, and the placebo effect. The account of delusions that I support holds that delusions are acceptances.
The interests I list above lead to more general questions about the nature of mental state assignment. When is it appropriate to posit novel mental states and novel propositional attitudes? Philosophers often give explanations of intentional action in terms of "belief-desire psychology.'' This could mean that beliefs and desires are only two states out of many we could call upon. However, in practice, beliefs and desires are given a place of privilege, appearing in most explanations. There is a tendency to argue as if the mind is sparse rather than lush. Why are beliefs and desires so prominent in the tradition? Why do decision theorists model beliefs and desires (using credence and utility functions) and not other attitudes? The issue is even further complicated by the fact that psychological posits are often thought to be unlike the posits of other sciences. Psychological theory construction, it is said, is subject to rationality constraints. I deny that there are any rationality requirements on mental state ascription.
The Concept of Mental Disorder
What’s the difference between clinical depression and “normal” sadness? What distinguishes mental disorders from strange personality quirks, individual characteristics, or moral failings? The concept of mental disorder seems important in adjudicating certain questions about the ethics of psychiatry. Many have worried that the concept has become too broad. This leads us to pathologize healthy character traits, which in turn homogenizes culture, leads to drugs being overprescribed, and plays havoc with our notions of will and moral responsibility. Are these claims true? I propose a pragmatist approach. What is the function of the concept of disorder? Why do we need a concept of mental disorder at all? It might turn out that no single concept can coherently fulfill all the functions we demand.
Computer engineers make a distinction between hardware problems in a computer (such as a broken fan that causes overheating and then a crash) and software problems (a virus or bad code that causes a crash). Psychiatry is often thought of as the study of "software problems" of the mind. A psychiatric disorder is, metaphorically, a mind virus. Neo-Kraepelians, named after the early psychiatrist Emil Kraepelin, deny this. They claim that psychiatric disorders are simply syndromes -- collections of symptoms -- and not an underlying pathology that gives rise to the syndrome. Consider insomnia. To have insomnia is just to be unable to sleep easily. There needn't be a common pathology underlying all cases of insomnia, either at the hardware or the software level. Neo-Kraepelians claim that this is true of many psychiatric disorders, such as depression or personality disorders; so, psychiatrists should avoid postulating aetiologies. I am interested in the significance of neo-Kraepelianism for theories of mind and for theories of psychiatric intervention.