Monothematic delusions are bizarre beliefs which are often accompanied by highly anomalous experiences. For philosophers and psychologists attracted to the exploration of mental phenomena in an evolutionary framework, these beliefs represent—notwithstanding their rarity—a puzzle. A natural idea concerning the biology of belief is that our beliefs, in concert with relevant desires, help us to navigate our environments, and so, in broad terms, an evolutionary story of human belief formation will likely insist on a function of truth (true beliefs tend to (...) lead to successful action). Monothematic delusions are systematically false and often harmful to the proper functioning of the agent and the navigation of their environment. So what are we to say? A compelling thought is that delusions are _malfunctioning_ beliefs. Compelling though it may be, I argue against this view on the grounds that it does not pay due attention to the circumstances in which monothematic delusions are formed, and fails to establish _doxastic_ malfunction. I argue instead that monothematic delusions are _misfunctioning_ beliefs, that is, the result of mechanisms of belief formation operating in historically abnormal conditions. Monothematic delusions may take their place alongside a host of other strange beliefs formed in difficult epistemic conditions, but for which no underlying doxastic malfunction is in play. (shrink)

In this chapter we argue that some beliefs present a problem for the truth-aim teleological account of belief, according to which it is constitutive of belief that it is aimed at truth. We draw on empirical literature which shows that subjects form beliefs about the real world when they read fictional narratives, even when those narratives are presented as fiction, and subjects are warned that the narratives may contain falsehoods. We consider Nishi Shah’s teleologist’s dilemma and a response to it (...) from Asbjørn Steglich-Petersen which appeals to weak truth regulation as a feature common to all belief. We argue that beliefs from fiction indicate that there is not a basic level of truth regulation common to all beliefs, and thus the teleologist’s dilemma remains. We consider two objections to our argument. First, that the attitudes gained through reading fiction are not beliefs, and thus teleologists are not required to account for them in their theory. We respond to this concern by defending a doxastic account of the attitudes gained from fiction. Second, that these beliefs are in fact appropriately truth-aimed, insofar as readers form beliefs upon what they take to be author testimony. We respond to this concern by suggesting that the conditions under which one can form justified beliefs upon testimony are not met in the cases we discuss. Lastly, we gesture towards a teleological account grounded in biological function, which is not vulnerable to our argument. We conclude that beliefs from fiction present a problem for the truth-aim teleological account of belief. (shrink)

In philosophy, psychiatry, and cognitive science, definitions of clinical delusions are not based on the mechanisms responsible for the formation of delusions, since there is no consensus yet on what causes delusions. Some of the defining features of delusions are epistemic and focus on whether delusions are true, justified, or rational, as in the definition of delusions as fixed beliefs that are badly supported by evidence. Other defining features of delusions are psychological and focus on whether delusions are harmful, as (...) in the definition of delusions as beliefs that disrupt good functioning. Even if the epistemic features go some way towards capturing what otherwise different instances of clinical delusions have in common, they do not succeed in distinguishing delusions as a clinical phenomenon from everyday irrational beliefs. Focusing on the psychological features is a more promising way to mark the difference between clinical and non-clinical irrational beliefs, but there is wide variability in the extent to which delusions are psychologically harmful, and some everyday irrational beliefs can affect functioning in similarly negative ways. In this chapter we consider three types of belief that share similar epistemic features and exhibit variation with respect to how psychologically harmful they are: (1) delusions of thought insertion, (2) alien abduction beliefs, and (3) self-enhancing beliefs. In the light of the similarities and differences among these cases, we highlight the difficulty in providing an answer to what makes an irrational belief delusional. (shrink)

In philosophy, psychiatry, and cognitive science, definitions of clinical delusions are not based on the mechanisms responsible for the formation of delusions. Some of the defining features of delusions are epistemic and focus on whether delusions are true, justified, or rational, as in the definition of delusions as fixed beliefs that are badly supported by evidence). Other defining features of delusions are psychological and they focus on whether delusions are harmful, as in the definition of delusions as beliefs that disrupt (...) good functioning. Even if the epistemic features go some way towards capturing what otherwise different instances of clinical delusions have in common, they do not succeed in distinguishing delusions as a clinical phenomenon from everyday irrational beliefs. Focusing on the psychological features is a more promising way to mark the difference between clinical and non-clinical irrational beliefs, but there is wide variability in the extent to which delusions are psychologically harmful, and some everyday irrational beliefs can affect functioning in similarly negative ways. In this chapter we consider three types of belief that share similar epistemic features and exhibit variation with respect to how psychologically harmful they are: (1) delusions of thought insertion, (2) alien abduction beliefs, and (3) self-enhancing beliefs. In the light of the similarities and differences between these cases, we highlight the difficulty in providing an answer to what makes an irrational belief delusional. (shrink)

Jessica Wilson has recently offered a more sophisticated version of the self-defeat objection to Cartesian scepicism. She argues that the assertion of Cartesian scepticism results in an unstable vicious regress. The way out of the regress is to not engage with the Cartesian sceptic at all, to stop the regress before it starts, at the warranted assertion that the external world exists. We offer three reasons why this objection fails: first, the sceptic need not accept Wilson’s characterization of the sceptical (...) thesis and thus need not start her regress; second, even if she did commit to the regress, it would not undermine scepticism in the way Wilson envisages; and third, the appeal to mental state scepticism which is necessary to generate the second and subsequent steps in the regress is not justified. (shrink)