Philosophical position like solipsism are well thought out and definitely rational. Nevertheless it's unusual from practical commoner's point of view. Is it possible that mental condition like de-realization syndrome was historically responsible for view like solipsism to develop? I also imagine the possibility that mentally atypical folks are more likely to do hard-core philosophy stuff and perhaps most ancient philosophers were of that variety.

Here are two quotations of David Hume.

But what have I here said, that reflections very refined and metaphysical have little or no influence upon us? This opinion I can scarce forbear retracting, and condemning from my present feeling and experience. The intense view of these manifold contradictions and imperfections in human reason has so wrought upon me, and heated my brain, that I am ready to reject all belief and reasoning, and can look upon no opinion even as more probable or likely than another. Where am I, or what? From what causes do I derive my existence, and to what condition shall I return? Whose favour shall I court, and whose anger must I dread? What beings surround me? and on whom have, I any influence, or who have any influence on me? I am confounded with all these questions, and begin to fancy myself in the most deplorable condition imaginable, invironed with the deepest darkness, and utterly deprived of the use of every member and faculty.

Most fortunately it happens, that since reason is incapable of dispelling these clouds, nature herself suffices to that purpose, and cures me of this philosophical melancholy and delirium, either by relaxing this bent of mind, or by some avocation, and lively impression of my senses, which obliterate all these chimeras. I dine, I play a game of backgammon, I converse, and am merry with my friends; and when after three or four hours’ amusement, I would return to these speculations, they appear so cold, and strained, and ridiculous, that I cannot find in my heart to enter into them any farther.

  • Solipsism is a philosophical position; but it's one to steer away from not to - in that sense it's not generally seen as 'rational'; for example Kant in his critical philosophy demonstrates that his philosophy doesn't lead to that boxed in corner; despite his copernican turn away from the object to the subject. Aug 23, 2015 at 10:01
  • @MoziburUllah "Solipsism is a philosophical position; but it's one to steer away from not to - in that sense it's not generally seen as 'rational'; " Why is it thought as such? Aug 23, 2015 at 10:26
  • Well, from a theological/philosophical context it's to position yourself as God, creator of worlds; from a common sense perspective no serious philosopher has held it; can you name one? Aug 23, 2015 at 10:32
  • When philosophy system building it's a test-case that one shows that the system doesn't demonstrate; compare with building foundations for arithmetic a la Russell; had his system shown that 1+1 does not equal 2, he would not have said so much for fact; but would have had to modify his system such that this holds. Aug 23, 2015 at 10:36
  • In physics they check whether their model allows brain in the vat and use it as a criterion for rejecting the model. Same with philosophy? Interesting. But I'll not be fully satisfied until I get some concrete examples. If you may? :) Aug 23, 2015 at 10:41

6 Answers 6


Philosophical position like solipsism are well thought out and definitely rational.

Agreed, and according to wikipedia solipsism was formalized by the Sophists, for whom it sensibly enough was a rationalization for or foundation of other Sophist style thought. This doesn't mean they needed to literally believe it, but they had to see it the way you've stated, as coherent.

You might have a pretty sound epistemology by starting with solipsism and Occam's razor, and rejecting (or neutralizing the significance of) the former via the latter. Kind of Descartes. But this is a tangential point.

So, they were not deranged, they were Sophists. There's a difference.

mentally atypical folks are more likely to do hard-core philosophy stuff

I'm presuming you say that because most people aren't interested by "hard core philosophy" and feel there are better things to do. However, the same is true of math, science, and literature; most people do not engage in the study of any of these things except to the extent that they are forced to by law.

Being "atypical" does not mean you are mentally deranged, prone to hallucination, etc. This is why psychology is not just "mental pathology"; people can end up with very different beliefs but still pass the same basic tests of sanity.

  • It seems to hold from the opposite direction too. People suffering some psychiatric disorder (e.g de-realization syndrome) tend to become obsessed with philosophical topic like the nature of space , time , self, develop generalized doubt etc. Aug 23, 2015 at 16:53
  • No doubt some do, but I think they are still in a minority, just like healthy philosophers. Severe psychiatric cases I've observed (I'm no expert) do often seem to involve "ontological hallucinations", but not the conscious reflection upon them which I would consider philosophizing. I watched a documentary on childhood schizophrenia recently, one of the subjects of which seemed to have bizarrely semiotic hallucinations that reminded me of psychedelic drugs in sufficient doses. Despite this, she seemed like quite a smart kid, but I would not call her obsessions philosophy oriented. Aug 23, 2015 at 17:22
  • I guess my point is that while philosophy can have a "crazy and obsessive" character, I think it is qualitatively different than a real psychiatric problem. There are definitely very famous and influential philosophers I cannot read an entire page of without going, "You're completely nuts," but I would attribute this to psycho-social causes -- which as per the last paragraph in my answer can be very diverse -- and not a bone fide mental disorder. Aug 23, 2015 at 17:30
  • Is it fair to say that philosophers can temporarily attain the mental state of a psychiatric patient? Aug 23, 2015 at 17:46
  • I felt that way when I was reading Wittgenstein's On Certainty. May be voluntary insanity is a talent of great philosophers. Aug 23, 2015 at 17:48

Ja'far ibn-Sadiq an Islamic scholar claims that our soul is a soft material, not of something that is beyond matter!

And as much as every matter has an effect on another, the soul does have its affect on the body and can create mental illness/happiness, death, or sleep. The soul is through the body...like the light through a light bulb.

Reason that our soul does affect our body:
There are 2 types of soul:

-Brute-soul...as humans and animals have.

-Wisdom-soul...as we humans have.

-When we are awake we have both souls.We eat,walk, breath, urinate, sleep, super-basic-processing,etc. ( brute-soul) and talk, think, contemplate, socialize, admonish, worship,etc. (Wisdom-soul)

-When we are sleep the Brute-soul sticks with the body, and keeps us alive...moving a little bit...yet we see dreams (that are rarely true) with the wisdom-soul.
-When we die, both go away from us.

-When we are depressed or sad as a result of jealousy, nihilism & skepticism (a philosophical thought),poorness, loneliness, grudge,impatience, etc....then brute-soul affects the body and sometimes people feel sick and ill.


In response to the general question of whether there is a connection between the two, I would say definitely yes. I will explain my reasons for that first before giving my thoughts on the more specific questions.

To discuss this one first needs a definition of mental illness. By current standards a rigorous source would be the conditions listed in the DSM, yet it is significant that this list changes (fairly rapidly) over time to accommodate changes in societal norms, as well as changes in our understanding of psychology. One only has to look back a couple hundred years to see women institutionalized for lack of sexual interest in their husbands, diagnosed with "hysteria."

My point is that mental illness is culturally relative. So is what constitutes respectable philosophical thought. People that were not credited as philosophers in the past on account of mental illness have certainly had ideas that would have merit today. People currently dismissed as mentally ill are also likely having ideas that would be respected by philosophers in the future (or the past). Most importantly, a part of philosophy is considering perspectives beyond the status quo even if they are uncomfortable, and mental illness is a label often attributed to such things so that we may dismiss them. In my opinion this makes the relationship between the two intimate.

More specifically, you express interest in the idea of a particular symptom of mental illness (delusional perhaps) gaining merit as a philosophical thought. When it comes to a person's concept of reality, it is difficult to distinguish a psychological symptom from their conscious experience as a whole. For example I have heard people say that existentialism is basically the result of some very depressed people getting up on the wrong side of the bed too many times. While this may sound naive at first, consider that Kierkegaard and Nietzsche did suffer from serious boughts of depression. Many existentialists (like Nietzsche) have been institutionalized and have committed suicide. Was this a result of the depths they dug into mentally or was it the other way around? I think that the more deeply one investigates this and other examples, the more one would find a fundamental entanglement of philosophical thought with mental illness.

Here is another example. Consider extreme psychotic mania that can occur in bipolar disorder. People in these states, while irrational and unpredictable, can often have a contagious effect on those around them, spreading a deeply passionate sense of freedom and transcendence of daily monotony. Historically this condition has been perceived as religious ecstasy. Perhaps Christianity is an example of a philosophical idea conceived of as a result of madness. Afterall by current psychological standards what would we say about a man who claims to be God and wonders the countryside convincing people wine is his blood, and getting men to leave their jobs and follow him? Whether or not an idea is labelled "mad" almost seems arbitrary if one tries to be objective.

  • Not to complicate things, but beware that the (as you point out, somewhat political) category of "mental illness" is not just about dismissal -- it is also about safeguarding. Don't throw out the baby with the bathwater. Some kinds of crazy need protection from other kinds of crazy, if you get my point (and all apologies if "crazy" is taken prejudicially/derogatorily, etc...); not all kinds of crazy get binned, some of them are in charge of the show. We're all crazy for playing see-no hear-no speak-no Dec 17, 2015 at 23:16
  • There is a component of protecting the mentally ill from themselves and each other but I don't think this is relevant to the question.
    – j0equ1nn
    Dec 17, 2015 at 23:18
  • The question is very simplistic in that it assumes the validity of something I think you are (rightly) trying to pick apart. I just included the caveat because I worry that people read this kind of thing and think, "Oh, we don't need to help or protect those people, we just need to talk about perspectives beyond the status quo..." ;) Dec 17, 2015 at 23:23
  • Okay sure. I guess a feel the way I do about a lot of philosophical questions: there is a problem with the implicit assumptions.
    – j0equ1nn
    Dec 18, 2015 at 0:27
  • 1
    While it's definitely true that mental illness is not pure psychology but also a political game, that was not per se the question. The question is how philosophy relates to mental illness, and you do address that briefly at the top and bottom, but that part is nebulous. Could make that part clearer and more substantial? The other point does not need the amount of space you're giving it to make a good answer.
    – virmaior
    Dec 18, 2015 at 2:18

I don't know of any philosophers who were mentally ill, though obviously some were idiosyncratic.

Unlike F.H. Bradley, whose feline-directed nocturnal activities were not so benign, McTaggart saluted cats whenever he met them (Rochelle 1991, 97). (F.H. Bradley preferred to shoot cats; see the entry on F. H. Bradley.) His preferred method of transportation was a tricycle, a fact which led a Cambridge paper to publish the following poem about him:

Philosopher, your head is all askew; your gait is not majestic in the least; you ride three wheels, where other men ride two; Philosopher, you are a funny beast. McTaggart was delighted by this poem

Clearly there is a rich vein of madness in the writing of poets. E.g., I read a long review on Modernist poetry which claimed that Frost was the only "great" Modern poet who wasn't insane (Eliot, Yeats, Pound...).


Godel had an anxiety disorder, and very probably was on the autistic spectrum. He thought everyone except his wife was trying to poison him. After his wife died, he pretty much stopped eating. He is of course considered a mathematician, but there can be no doubt his Incompleteness Theorems are among the most important philosophical insights of the last century.

Einstein would have been diagnosed as autistic as I understand it, because of his late language development - I don't think he spoke until he was 9. Again deep insights, also very much a humanist, and made powerful statements outside his field that are still widely quoted.

Martin Luther undoubtedly had a strong case of Obsessive Compulsive Disorder (details in the Sapolsky vid linked below), and his thoughts reshaped Christian philosophy and European politics.

Nietzsche is now thought to have been bipolar. He had a total nervous mental breakdown some ten years before he died, triggered by seeing a horse being badly beaten in the street. He burst into tears hugging the horse, and never wrote again. It used to be thought this was a result of tertiary syphilis, but scholars now think not.

So, I would approach this by looking at what 'mental illness' is. Nowadays, we might be more inclined to use the terms neurodivergent, and contrast to ordinary 'neurotypicals'. Biologist Robert Sapolsky describes here how mild schizophrenia and mild ADHD can be linked with prophecy and ritual activities, and how they can be related to evolutionary drivers. Certainly many philosophers, like Diogenes or Descartes were quite odd people, and could definitely be called neurodivergent.

But consider cognitive bias. We calibrate ill vs health, typical vs divergent, by looking at other people. But what happens when society is irrational? How do we truly work out when we are unbiased, rational, sane, without simply looking at what others do? Perhaps the 'ultimate' example of that is the world of the film Dr Strangelove, which our understanding from now declassified Coldwar nuclear policies show was terrifyingly accurate, and involved total annihilation of all human life for a range of trivial and likely to happen reasons. You can say there was an animal-rationality to it if it was only posturing, but it was not sane policy (see The Fog Of War documentary for how truly crazy it got).

Cultures & communities of practice seem to be the way. The sangha in Buddhism, aim to keep a collective practice of calming and observing the mind through meditation and other practices. The scientific community don't have a simple rule-based scientific method, but a culture of critique and scepticism, and practices like peer review. The Socratic Method is not so much a set of rules, but committing to thinking together, sceptically. We can generalise these, by looking at Wittgenstein’s framework of 'modes of life', with their own ways of using words, expectations about framing questions and what counts as answering them, and so on. This links to the Private Language argument, the most devastating critique not only of solipsism but also idealism, because our concepts and their refinements are understood to be inextricable from communities of practice, to be meaningless and impossible 'solo'.

Mental illnesses, and cognitive biases, may trigger or shape our inquiries. I have noted before that Hobbes's view of human nature (a war of all against all) vs Rousseau's (the noble savage), probably tell us more about how those individuals related to their own impulses, than about human nature. But through careful practice, and community comment, we can come to conclusions that go beyond those biases. Hume's point that "reason is and ought only be slave of the passions" parallels this, our deep motivations may always be opaque to us. The lesson of looking at cognitive biases is, as Robert Heinlein put "Man is not a rational animal, he is a rationalizing animal", we use our reasoning to navigate and move ourselves, not just to examine. We should look not only to our own clear thinking, but to communities that share it, to try and understand, define, and live, a more sane life.


Whenever I think about this issue, I am reminded of the Greek myth of Cassandra, who was given the gift of foretelling the future, and then cursed so that no one would ever believe her. Doing philosophy often feels like that...

It's worth keeping in mind that philosophically-minded people often have artistic temperaments. They have keen insights: they see things that other people don't, understand things in ways that other people miss, and struggle trying to find ways to express that vision so that others can see it as well. A painter spends a good portion of her life mastering the techniques of brush and color; a sculptor spends hours on end experimenting with the 'feel' of a chisel on stone; a philosopher spends his time crafting words into arguments and arguments into worldviews. Failures is just as disheartening for a philosopher as for an artist, and success is just as exhilarating. And like everyone with an artistic temperament, philosophically-minded people are prone to neurosis and mood disorders. They experience depression, anxiety, eccentricity, intense egotism, unreasonable anger, world-shattering doubts. I've long held a pet theory that every philosopher goes through a "Listen, Little Man!" stage (taken from the title of a book by Wilhelm Reich) in which they publicly or privately rebuke the world at large for not 'seeing' what they (as philosophers) see so vividly. Read a few pages of that book, and you'll get a sense for the deep turmoil of someone trying (and failing) to express his philosophical vision of the world.

But that being said, neurosis is not psychosis and is not personality disorder; neurosis is a cognitive maladjustment to a world one cannot quite fit into, not a physical malformation of the brain or a deep-seated fracture in the psyche. I mean, I assume there are as many psychotics and clinical narcissists and such among philosophers as among the general population, but serious disorders of that sort do not lend themselves to philosophy any more than they lend themselves to (say) being a plumber.

Solipsism in particular isn't a matter of 'de-realization syndrome' or any other deep malfunction in cognitive processing. Solipsism (and related schools like nihilism and cynicism) is an intellectual defensive position: an effort to retreat back to something solid on which to base arguments, redacting everything epiphenomenal. Think of it as the equivalent of the Abstract movement in modern art, that discards all classical forms and styles of art and reduces itself to a play of color and visual texture. Solipsism is based on a keen isight about epistemology that most people do not quite see — the fundamental problem of how we could know that anything outside our sense-experience exists, including whether other people exist with their own idiosyncratic sense-experiences — and while that insight can be a focus for neurosis, it is not the product of some underlying mental disorder.

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