Philosophy is all about questioning reality. Epistemology is about questioning our knowledge of reality and metaphysics is about reality itself. Philosophical scepticism can lead people to make bizarre hypotheses, such as the idea that we might be brains in vats, or victims of Descartes’ evil demon, or whatever. So my question is: where does philosophical scepticism end and downright mental abnormality begin?
Solipsism, external world scepticism and the like are commonly considered by philosophers, and they are not considered delusional. And yet, ‘solipsism syndrome’ and ‘the Truman Show delusion’ are recognised as mental illnesses. The content of these beliefs seems similar, so why are solipsism and external world scepticism considered rational whereas solipsism syndrome and the Truman Show delusion considered mental illnesses?
The best answer I can think of would be that philosophical scepticism is based on rational questioning and that it is not firmly held, like a delusion would be. Whereas, the Truman Show delusion is fixed and is based on irrational inference from events to the belief that reality is not what it seems/reality is based around you/whatever. But this is not totally satisfying for me. How can we so clearly draw the line between “rational questioning” and “irrational inference”?
This question has some personal relevance to me because I am often led to think in unusual ways about things, and I am not sure whether I am being epistemological or whether I am downright mentally abnormal. For example, if I watch a film I have already seen, and something seems different from how I remember it, I can sometimes be led to wonder whether this could be like a sign from God/whatever that the reality I experience is not ‘true reality’, and God/whoever is 'up there' is trying to show me this, by showing me the internal contradictions inherent in the reality I experience. And later, I realise that a much more rational explanation would simply be that my memory was poor with regards to what happened in the film, and then it bothers me that I would even think along the ‘sign from God’ lines, and I am left genuinely frightened for my mental health. I have actually explained the way I sometimes think to two ‘professionals’ (a physician and a psychologist) who I was seeing for largely unrelated reasons, and they have both assured me that I am not crazy and that I don’t have schizophrenia or any serious mental illness.
Aside from the assurances of the physician and the psychologist, two things make me slightly more confident about my own sanity: 1. When I think in the way I described above, it is not as if my thoughts are fixed, deeply-held delusions which affect the way I live my everyday life, they are just momentary ideas which I later go on to self-analyse myself about; and 2. It is considered ‘normal’ to believe in ghosts and horoscopes and New Age bullshit, and how things like a baby surviving a tornado or the Pope surviving an assassination attempt are signs of divine intervention, which I think are at least as irrational as the way I sometimes think.
Still though, I have no idea where rational epistemological scepticism ends and psychiatric delusion begins. Does anybody have any better suggestions with regards to how to demarcate the two? And has anybody else been led to think in the way I described above, and been worried about whether they were being epistemological or whether they had something wrong with them?
