Philosophical Phun- Delusion:o)

Of all psychiatric concepts, it is probably delusions that have received the most extensive recent treatment from philosophers. Here the issues straddle philosophy of mind and philosophy of science. Some theorists have raised conceptual difficulties for accounts of delusions, others have sought to frame scientific hypotheses that can explain delusions in terms of information-processing deficits or other subpersonal problems.

Like many other psychological concepts, the concept of delusion has a fairly explicit and self-conscious scientific use and a variety of commonsense uses. There is considerable overlap between some psychiatric uses and some casual employments of “delusion”. But there are clearly everyday occasions when “delusion” merely refers to a belief that seems obviously false or unwarranted to the speaker. I might call you delusional when you announce that you expect to buy a four bedroom house in your neighbourhood for what you can afford to pay, without meaning that your reasoning is symptomatic of a psychotic illness; it is just wishful thinking.

But delusions in a technical sense are manifestations of psychosis. A delusion can be defined as ‘A false belief based on incorrect inference about external reality that is firmly sustained despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary ….’.

A purely philosophical approach to explaining delusions concentrates on the role the delusion plays in the subject's mental life, as understood in terms of some theories in philosophy of mind. Recent work in this area suggest that the role of the delusion in the subjective mental life of the deluded person that is critical.

You can look at the current political situation [or insert your situation here] and see how such an impassioned position has been established, complete with distortions of the past, half-truths, and partial disclosures to suit the perceived position - that whenever facts are introduced that directly refute the delusion are provided, they are outright discarded and often mocked, because to do otherwise would challenge the mental state of the delusionee.  

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Philosophical Phun - Delusions :o)

Delusions are a symptom of psychiatric disorders such as dementia and schizophrenia, and they also characterize delusional disorders.

As in some cases of erotomania, the content of a delusion can be mundane, and does not even need to be false: one can have the delusion that one's spouse is unfaithful or that one's neighbor is a terrorist, and these may turn out to be true beliefs. As in the Cotard delusion, the content of a delusion can be bizarre.

Here are some other examples: mirrored self misidentification is the delusion that the person in the mirror is not one's reflection but a stranger, and the Capgras delusion is the delusion that the spouse or a relative has been replaced by an impostor.

All types of delusions are rigid to some extent, that is, they are not easily given up because they tend to resist counter evidence.

Delusions may be inconsistent with a person's beliefs and behavior, are typically unresponsive to both counter evidence and counterargument, and are often defended by weak evidence or argument. The empirical literature suggests that the reasoning performance of people with delusions reflects data-gathering and attribution biases.

For information, click the link :o)

The most prominent delusion I can think of right now is the "birther" movement, followed closely by the "death panelists". Can you think of other examples?