Can a solipsist doubt their beliefs? Yes.

I might have said that a solipsist can only become a solipsist by doubting that anything they perceive did not originate with themselves. I also might have said that they can only become a solipsist by assuming that everything they perceive does originate within themselves.

One man's assumed positive is another man's doubted negative.

Can a solipsist doubt their beliefs? Yes. — VagabondSpectre

But, a solipsist's world is one full of absolute certainty, so how can doubt arise in such a world?

By doubting that the world is full of absolute certainty to begin with, of course!

But, surely that's illogical.

But, surely that's illogical. — Posty McPostface

Solipsists cannot logically reason that they are in a solipsistic universe using the following argument:

P1: I would have certainty in a solipsistic universe
P2: I am in a solipsistic universe
C1/P3: Therefore I have certainty
C2: Therefore I am in a solipsistic universe

If we doubt that we live in a solipsistic universe , then we're not sure if we have certainty (heh). The circularity here is informally called "begging the question", as the conclusion is fully contained in one of the premises. The premise/assumption that we live in a solipsistic universe cannot be magically self-reinforcing. If we doubt it, the conclusion is no longer valid.

Therefore a true/authentic solipsist cannot doubt?

Well, if solipsism grants absolute certainty, and someone was validly absolutely certain that they were in a solipsistic universe, then they by definition would not doubt.

But, maybe they accidentally bonk their head on itself one day and get confused, and begin doubting in error :)

But, maybe they accidentally bonk their head on itself one day and get confused, and begin doubting in error — VagabondSpectre

What if instead of bonking their heads they, the solipsist, encountered Descartes evil demon, which would prod the person to doubt. Would it be such an "evil demon" anymore?

It would be themselves if the universe was solipsistic so no. If the universe was not solipsistic, then it would be better characterized as an angel of enlightenment.

It would be themselves if the universe was solipsistic so no. If the universe was not solipsistic, then it would be better characterized as an angel of enlightenment. — VagabondSpectre

So, again, the solipsist cannot logically doubt. I rest my case.

My point in the whole topic was to illustrate that solipsism can serve by extension as an argument against the evil demon or Cartesian skepticism. The process of doubting itself presupposes knowledge.

In light of this, if one can doubt, then they are most certainly not a solipsist, and hence the evil demon aint that evil, by extension.

The question contains some presupposition that is difficult to both escape and still provide an answer.

'Can'

If anyone solipsist or otherwise can do anything this presupposes freedom.

'a solipsist'

Suggests more than one solipsist which is incompatible with pure solipsism.

'doubt'

Is an activity and contains the supposition of control and hence freedom.

The solipsist is unfree to entertain the ism.

M

" the solipsist cannot logically doubt."

I'll need to see your definition of solipsism. By my definition, a solipsist is someone who believes his mind, and only his mind, exists. I've never seen this belief stated in terms of being something of which the solipsist is absolutely certain about. A lack of absolute certainty implies some level of doubt.

Red marks conundrum:



(from something I typed up elsewhere (can maybe reproduce here if anyone cares))

I suppose a solipsist cannot doubt that their experiences exist (like everyone else), but they could doubt whatever ideas about what they are.

I'll need to see your definition of solipsism. By my definition, a solipsist is someone who believes his mind, and only his mind, exists. I've never seen this belief stated in terms of being something of which the solipsist is absolutely certain about. A lack of absolute certainty implies some level of doubt. — Relativist

Well, if a solipsist doubts that they are the only self, then that's no longer solipsism, yes?

No. As I said, belief does not entail absolute certainty.

No. As I said, belief does not entail absolute certainty — Relativist

So, you're saying that the belief that I am a solipsism, is open for doubt? Again, that's not solipsism.

I must be certain that everything I believe is true for me to be a solipsist.

I suppose a solipsist cannot doubt that their experiences exist (like everyone else), but they could doubt whatever ideas about what they are. — jorndoe

What do you mean by that? I read the thread; but, in my opinion differences between that and what get muddy when confronted with solipsism due to the very nature of the mind of the solipsist.

What do you mean by that? — Posty McPostface

A hyper skeptic parsimonious solipsist weirdo may doubt anything beyond mere appearances (cf "esse est percipi").
Say, when taking a walk on the street they may doubt there's anything more to the buildings and pedestrians than what they experience.
So, no other minds, no other self-awarenesses, no other experiences (that we generally ascribe to each other), for example, just the solipsist's own experiences. ← implosion

↑ what the experiences are could be doubted

But, whatever all those experiences are, their mere existence cannot be doubted.
Analogous to: something exists, since otherwise this statement wouldn't.
Not exactly informative, but, hey, ... :)

↑ that experiences exist, whatever they may be

Are you 1) claiming belief entails certainty; 2) (re)defining solipsism as the certainty that only the solipsist's mind exists; or 3) suggesting certainty is entailed by something in the common definition of "solipsist"?

I'm still not getting the discrepancy between what and that statements for a solipsist. In my mind, they are both the same for a solipsist...

Are you 1) claiming belief entails certainty; 2) (re)defining solipsism as the certainty that only the solipsist's mind exists; or 3) suggesting certainty is entailed by something in the common definition of "solipsist"? — Relativist

All three, although #2 isn't me redefining solipsism, I think.

Under your premise that belief entails certainty, your conclusion that a solpsist cannot doubt is trivial. But I'm curious: do you actually regard all of your beliefs as absolute certainties?

If I were a solipsist, yes.

I'm a solipsist! AMA

I don't understand why you make the distinction "if I were a solipsist." Do you define "belief" differently for solipsists? Previously you said you said you agreed that "belief entails certainty," so this suggests that you are absolutely certain about all your beliefs, irrespective of whether you are a solipsist.

No, a solipsist lives in a hermetically sealed epistemological certain world. Therefore their beliefs are not prone to doubt. I put it all into words in the OP.

I admit to having overlooked that you stipulated, "Given that solipsism implies epistemological certainty of ones world".

This stipulation indeed entails an absence of doubt - trivially, since certainty = an absence of doubt. I just question that this is a standard view of solipsism. One could, in theory, believe his mind is all that exists - based on a standard view of belief - which admits of varying degrees of certainty. Such a person could therefore have some degree of doubt, and it seems to me this fits a definition of solipsism, even if not the definition you choose to use.

Solipsism is 'intellectual' language game. It is impossible in reality. Language requires shared meaning. Shared meaning requires a plurality of minds.

I think it's interesting to ask: why are there actually no solipsists?

IMO, it's because to be a solipsist, one has to abandon hardwired beliefs. Belief in a proposition is not simply a bit being turned on, it entails a psychological state. We are hardwired to perceive the world as we do. Beliefs don't drop away because we can't rationally justify them based on priors, they only drop away if we become convinced they are false.