To say that one is a solipsist is to affirm that one is one and the same with the world, à la Wittgenstein.

Hence, indubitable certainty or epistemic solipsism where no doubt can arise.

Therefore a solipsist cannot doubt.

Solipsism simply cannot be true if the solipsist can doubt.

Prove me wrong. — Shawn

I could but I'm tired of arguing with myself and ending up doubting myself.

I could but I'm tired of arguing with myself and ending up doubting myself. — Fooloso4

For all that exists, what is it that you are doubting as a solipsist. Are you really a solipsist?

Of course.

Either way, particular or universal, the self is the ultimate truth for the solipsist in His or Her own World, epistemically.

So, you cannot be doubting, surely?

Either way, particular or universal, the self is the ultimate truth for the solipsist in His or Her own World, epistemically. — Shawn

I tell myself this all the time, but no one listens. And by no one, of course, I mean me.

I tell myself this all the time, but no one listens. And by no one, of course, I mean me. — Fooloso4

Then how can you doubt yourself as a solipsist when you are the same as the World? Or does this world expand when you doubt and can learn new things?

By inference aren't you epistemically certain of any particular of what you are, being a solipsist?

Sorry Shawn, I was joking. Taking the position that I can only be sure of my own existence, everything I said, beginning with the fact that I responded to you contradicts solipsism.

Sorry Shawn, I was joking. Taking the position that I can only be sure of my own existence, everything I said, beginning with the fact that I responded to you contradicts solipsism. — Fooloso4

Well, yes it's all fun and games. But, I'm interested in the notion that doubt creates a bedrock (Wittgenstein/Descartes) where knowledge can begin. Therefore, the thread.

Do you agree that epistemically, this is the shortest path to disproving solipsism since the solipsist cannot logically doubt?

@Banno, can a solipsist logically doubt?

A solipsist doubts that there are other minds.

The fundamentally tessellating nature of the understanding disproves solipsism—once we hit the edge of solipsistic understanding, we’re warped directly back to a reality with others.

Do you know any solipsists? Exactly.

A solipsist doubts that there are other minds. — 180 Proof

Not true, given a bona fide definition and scope of the issue. Intentionally there's no doubt. Extensionally there should be none.

Just doing a second reading, and I suppose this should read:

A solipsist knows there are no other minds.

Makes no sense. If only your mind is real nothing could count as evidence for or against any claim or belief. Thus, a solipsist can only suspend judging as true or false (i.e. doubt) or simply ignore any prospective counterfactual. A solipsist is merely a metaphysical neurotic.

Makes no sense. If only your mind is real nothing could count as evidence for or again any claim or belief. Thus, a solipsist can only suspend judging as true or false (i.e. doubt) or simply ignore any prospective counterfactual. A solipsist is a metaphysical neurotic. — 180 Proof

More of the sort of epistemically, they are certain of everything going around them, to the best of their knowledge.

Nothing is "going on around them" just their thoughts; and without any mind-exterior (mind-independent) corroborating metrics implied by solipsism, a solipsist cannot believe in anyway distinguishable to herself from disbelieving; she only daydreams without cognitive or epistemic content. (See Witty's "Private Language Argument" for starters.)

solipsist cannot believe in anyway distinguishable to herself from disbelieving; she only daydreams without cognitive or epistemic content. — 180 Proof

Well, a person during the REM phase of dreaming is quite solipsistic, don't you think? And in even in a higher state of consciousness during a dream phase where the dreamer knows he or she is dreaming, as in what is called a "lucid" dream, that person is as close to what one may empirically describe as solipsism as can be.

Except solipsism is a commitment to a 'metaphysical fantasy' and not itself a mental state. Perhaps REM sleep / lucid dreaming "seems" solipsistic but they need not "seem" so in every case.

I'm expected to reply here, but have nothing to say. "The solipsist achieves no practical advantage from advancing his views".

Except solipsism is a commitment to a 'metaphysical fantasy' and not itself a mental state. Perhaps REM sleep / lucid dreaming "seems" solipsistic but they need not "seem" so in every case. — 180 Proof

Enabled by REM sleep, perhaps?

Epistemic solipsism seems to me to be a viable position to hold in regards to the indubitability of the solipsist's world, where he or she alone is the observer of the observed.

"The solipsist achieves no practical advantage from advancing his views". — Banno

Very true. But, technically, we have some idea of what solipsism may mean by the mere fact that we experience a world like a solipsist would every night when we dream. Ya, no?

"Indubitability" of seeming? Okay. "Epistemic solipsism?" I refer you again to Witty's "Private Language Argument" which makes the case that any discourse which is not public – not accessible by others – is nonsensical (e.g. babytalk), which includes "epistemic solipsism". The eye is not in its own field of vision, the hand can grasp anything except itself; other eyes and hands are entailed respectively in order to see eyes and to grasp hands. Touching involuntarily touches back – "solipsism", as Samuel Johnson quipped, it's refuted thus.

"Epistemic solipsism?" I refer you again to Witty's "Private Language Argument" which makes the case that any discourse which is not public – not accessible by others – is nonsensical (e.g. babytalk), which includes "epistemic solipsism". The eye is not in its own field of vision, the hand can grasp anything except itself; other eyes and hands are entailed respectively in order to see eyes and to grasp hands. Touching involuntarily touches back – "solipsism", as Samuel Johnson quipped, it's refuted thus. — 180 Proof

Thanks for the comment on the PLA. In like here's one:

P.M.S Hacker provides the following:

What the solipsist means, and is correct in thinking, is that the world and life are one, that man is the microcosm, that I am my world. These equations... express a doctrine which I shall call Transcendental Solipsism. They involve a belief in the transcendental ideality of time. ... Wittgenstein thought that his transcendental idealist doctrines, though profoundly important, are literally inexpressible.

— Hacker, Insight and Illusion, op cit., n. 3, pp. 99-100.

And something else that's pretty neat from the Tractarian:

5.64, Wittgenstein asserts that “Here it can be seen that solipsism, when its implications are followed out strictly, coincides with pure realism. The self of solipsism shrinks to a point without extension, and there remains the reality co-ordinated with it.”

And something else that's pretty neat from the Tractarian:

5.64, Wittgenstein asserts that “Here it can be seen that solipsism, when its implications are followed out strictly, coincides with pure realism. The self of solipsism shrinks to a point without extension, and there remains the reality co-ordinated with it.” — Shawn

Yes. Neither the solipsist nor the realist have any notion of "perspective" (other than in the sense of 'wrong/faulty', as in "People who see things from their own perspective don't see things as they really are, but only from their narrow, wrong viewpoint").
A sentence like "Things are the way I see them" is unintelligible to a realist, and if the solipsist is also a realist, then to such a solipsist as well. IOW, it's impossible to get through to such people and to meaningfully communicate with them, at least as far as metadiscussion goes.