What do you mean by proof? Usually in logic we refer to deductive arguments as proofs. However, sometimes people refer to inductive arguments as proofs (using the word proof more loosely), viz., that the evidence is strong enough to believe the conclusion follows. If anything, the preponderance of the evidence is against solipsism. No one has demonstrated logically that solipsism is true.

Because as far as I see you can't. There is no experiment you can construct that would prove it true because you can't test it. Even argument wise there is no way to prove it, it just assumes you are all there is. You couldn't prove it without invalidating it to begin with.

Which is why I'm heavily doubting not just my memory about what I read those years ago but if they actually did. But all I have is a very strong emotion that he certainly did but no memory of what was said, which means nothing.

I don't think anything is indubitable at least from what I've heard other people say. I could doubt this is in english as I might have been mislead a lot of the time.

I don't think we have a learned bias towards needing proof, quite the opposite actually. In fact we fail to notice how much we take for GRANTED in our lives. Like that we exist, we just take it as a given never questioning it, yet when asked to prove it you can't without something self referential or just flat assertions.

The arguments I offered rely on either principles (novacula Occami) or definitions (3 marks of existence & epistemically-limited ontology). You may indeed question their legitimacy.

What I find intriguing is that as @Banno so insightfully inquired as to who the proof is meant for, a person X,

attempting to prove solipsism implies

1. X exists (as the target of the proof) [re cogito ergo sum]. Proof serves the same function as thought/doubt.

And

X succeeding to prove solipsism implies

2. Others don't exist.

Solipsism can be about metaphysics. If one is the only person with a false/irrational belief, then one has to transcend "go beyond" the physical reality of the socius. Boom metaphysics. Your belief will never be true, therefore not epistemology, unless you change other minds. Then it is not metaphysics but epistem. — introbert

I don't think metaphysics is transcendence of the physical. It isn't confined to the physical though. Also I did argue from an epistemo-ontological view (re Idealism).

First, it is necessary to distinguish the main types of solipsism and discuss their interrelations.

1) Metaphysical (M)
2) Epistemological (E)
3) Psychological (P)

Initially, it seems that your post concerns E solipsism, in asking "How can one know whether or not one's mind is all that exists?". Thus buried in this question are a concept and a presupposition, namely that one is using a closed a-priori definition as to what one means by one's mind, relative to which one is asking whether there exists a type of evidence, that if observable to ones mind, settles the question as to whether one's mind is all that exists.

M solipsism on other other hand, isn't a presupposition, but a refusal to grant intelligibility to the idea that there exists anything outside of one's mind. This entails that one's mind isn't meant as a closed and static concept that is a priori definable, but as an open and adaptive concept that is rationally and empirically exhaustive of one's concepts and potential experiences to the point of closing off the domain of philosophical and epistemological inquiry.

Philosophies that are sympathetic towards M solipsism are phenomenalism and empiricism. We might recall Berkeley, who rejected the conceivability of an unobserved and unimagined tree, Wittgenstein who questioned the intelligibility of the distinction of idealism and realism, and Charles Sanders Pierce who considered the external world to be congealed mind. These philosophers weren't speculating that mind is an exhaustive substance, as when an E solipsist and his naive-realist opponent considers mentality to be an object for propositional analysis. Rather, those philosophers treated mentality as a meta-linguistic activity that is the very basis of any act of rational and empirical enquiry.

As such, it doesn't make sense to argue for or against M-solipsism, as an M-solipsist will always interpret the arguments of any purported opponent or critic M-solipsistically. Indeed an M-solipsist might even identify as a realist for all epistemological purposes.

P solipsism is a ruminative psychological condition experienced by amateur philosophers and isolated individuals such as astronauts, who mistake their narrow a priori self-concept for the world. Anyone who self-identifies as an M-solipsist runs the risk of experiencing this condition as a result of misunderstanding the meaning of M-solipsism.

As solipsism can be proved false, it follows that solipsism can be proved to be not true.

Taking solipsism as knowledge of anything outside one's own mind is impossible

I want to prove the proposition P that solipsism is false.

Start by assuming that Solipsism is true.

Assertion one: I have knowledge of the novel Don Quixote, but as knowledge of anything outside my mind is impossible, only my own mind could have created Don Quixote, and therefore I am a great writer.

Assertion two: this post fails to convince me that this is the best argument to prove that solipsism is false, therefore I am not a great writer.

As assertions one and two are contradictory, by the law of noncontradiction, proposition P is in fact true, ie, solipsism is false.

Exist from ex meaning out and sistere which is to stand. In essence, to exist is to stand outside (of one's mind).

Il est facile de voir que ... I don't exist!

This is a key topic in the prevailing ethos of anti-schizophrenia. The first issue is that, of course, solipsism is a phenomenon of indirect realism. Indirect realism is not disproven by the solipsistic extreme that the mind originates all reality, neither is Idealism disproven by the existence of the physical realm. Solipsism is a verifiable fact of 'psychology'. Practical knowledge has been developed through the objectification of solipsism, such as 'theory of mind', therefore, through it's existence what is considered normal psychology has not been taken for granted, and some understanding has been developed of epistemology etc. Arguing solipsism is not true, is like arguing idealism is not true, but the difference is that idealism has developed in the modern by the rejection of manifest irrationalities that occur in nature. Solipsism is true because it resides in all of us, it is part of our bodily power, it can help us and it can hurt us. That it is most noticeable, made an object, through its problematic manifestation, and not really noticed when it is functional, arguing against it is an absurd and ironic rational idealism. Ironic, because one is using solipsism in making solipsism purely an idea your mind can deny, without acknowledging that there is a material basis for it outside your mind that is undeniable. This is like a transcendental idealism, but by trying to transcend solipsism, one confines idealism to rational (normative, deindividuating) thought. Ultimately a disempowering belief. This disempowerment, rejection of solipsist negation of other minds, turns one into a mindless extrovert. A mindless extrovert is a fascist, a mindless introvert (solipsist) is a homeless schizo. The Deleuzian concept can be interpreted that the schizo is an oppressed introvert (lone thinker) in a socius of extroversion (collective doers), is about a broader philosophical project that makes the anti-solipsist into a useful marionette, and the solipsist into a tangled mess of strings that only the most powerful can unravel.

If solipsism is true, then everything I know, such as apples, mountains, other people, are parts that make up the whole me. If from these parts I become conscious of something that I didn't know before, such as hearing about a scientific law, seeing a Derain painting, being told about the opening times of a new restaurant, reading a McCarthy novel, but these parts are in fact part of myself as a whole, then I must have already known about them.

So how does something that I know about but am not conscious of become something that I am conscious of.

If solipsism is true, only I could have decided to be conscious of something that I was previously not conscious of. But if I was not previously conscious of something, how could I know to become conscious of it. The solipsist needs to explain how I can become conscious of something that I was not previously conscious of.

You are performing a reducio ad absurdum, taking solipsism to it's extreme conclusion to refute it. Indirect realism can be reduced to the absurd by taking it to solipsism. However, solipsism is like indirect reality, it is not completely of the mind, but it is a function of the body.

Pure solipsism is not a challenging philosophical exercise. You don't have to have any JTB about any of the things that you mention, they are merely objects of your creation that mean whatever you want them to. Everything that is, is possibly interpretable by an 'idea of reference' that relates to you. About you or against you. You immediately understand everything as if it orbits around you like a planet around the sun. Better yet, geocentric is more solipsistic than heliocentric.

Obviously some manifestations of solipsism can be deemed false/untrue/dysfunctional, but ultimately it has a power whether you call it will-to-power or something else, that is opposed to group-think, consensus, democracy, fascism, normativity, herd mentality, objectivity, collectivism, state-philosophy, psychiatry, etc.

You are performing a reducio ad absurdum, taking solipsism to it's extreme conclusion to refute it. Indirect realism can be reduced to the absurd by taking it to solipsism. However, solipsism is like indirect reality, it is not completely of the mind, but it is a function of the body. Pure solipsism is not a challenging philosophical exercise. — introbert

The title of the thread is "Can you prove solipsism true?"
Yes, an argument that refutes an absolutist metaphysical solipsism also leads to a refutation of sceptical epistemological solipsism. Indirect Realism is not a form of solipsism.

argument that refutes an absolutist metaphysical solipsism also leads to a refutation of sceptical epistemological solipsism — RussellA

It does, and it has. It may not be true by modern philosophical ideals, but it is a true force of nature.

Indirect Realism is not a form of solipsism. — RussellA

I didn't say that it was. However, indirect realism is the underlying phenomenon.

This is a key topic in the prevailing ethos of anti-schizophrenia. The first issue is that, of course, solipsism is a phenomenon of indirect realism. Indirect realism is not disproven by the solipsistic extreme that the mind originates all reality, neither is Idealism disproven by the existence of the physical realm. Solipsism is a verifiable fact of 'psychology'. Practical knowledge has been developed through the objectification of solipsism, such as 'theory of mind', therefore, through it's existence what is considered normal psychology has not been taken for granted, and some understanding has been developed of epistemology etc. Arguing solipsism is not true, is like arguing idealism is not true, but the difference is that idealism has developed in the modern by the rejection of manifest irrationalities that occur in nature. Solipsism is true because it resides in all of us, it is part of our bodily power, it can help us and it can hurt us. That it is most noticeable, made an object, through its problematic manifestation, and not really noticed when it is functional, arguing against it is an absurd and ironic rational idealism. Ironic, because one is using solipsism in making solipsism purely an idea your mind can deny, without acknowledging that there is a material basis for it outside your mind that is undeniable. This is like a transcendental idealism, but by trying to transcend solipsism, one confines idealism to rational (normative, deindividuating) thought. Ultimately a disempowering belief. This disempowerment, rejection of solipsist negation of other minds, turns one into a mindless extrovert. A mindless extrovert is a fascist, a mindless introvert (solipsist) is a homeless schizo. The Deleuzian concept can be interpreted that the schizo is an oppressed introvert (lone thinker) in a socius of extroversion (collective doers), is about a broader philosophical project that makes the anti-solipsist into a useful marionette, and the solipsist into a tangled mess of strings that only the most powerful can unravel. — introbert

Not true at all. It's not true just because it resides in all of us. And it definitely isn't a verifiable act of psychology (which suggests the opposite).

Not to mention not of your logic follows or makes any sense.

You are performing a reducio ad absurdum, taking solipsism to it's extreme conclusion to refute it. Indirect realism can be reduced to the absurd by taking it to solipsism. However, solipsism is like indirect reality, it is not completely of the mind, but it is a function of the body.

Pure solipsism is not a challenging philosophical exercise. You don't have to have any JTB about any of the things that you mention, they are merely objects of your creation that mean whatever you want them to. Everything that is, is possibly interpretable by an 'idea of reference' that relates to you. About you or against you. You immediately understand everything as if it orbits around you like a planet around the sun. Better yet, geocentric is more solipsistic than heliocentric.

Obviously some manifestations of solipsism can be deemed false/untrue/dysfunctional, but ultimately it has a power whether you call it will-to-power or something else, that is opposed to group-think, consensus, democracy, fascism, normativity, herd mentality, objectivity, collectivism, state-philosophy, psychiatry, etc. — introbert

Still wrong, again.

It's metaphysical solipsism not the "how can we know" one, because we really can't. WE can't even know if we exist, like I said.

Berkley can argue against and unobserved and unimagined tree all he wants it doesn't make it any less real. It's also why idealism died out I guess and why we follow science. The "if I don't see it it didn't happen or isn't real" is one of the easiest things to disprove.

Everything else you said is irrelevant to the topic.

That's the insanity of trying to prove it, on top of it being unprovable of course.

The standard you are holding solipsism to is not what it is but its absurd eventual conclusion. If you are asking if anyone can prove the absurd eventual conclusion is true, which is the argument against it, the discussion topic is meaningless.

I’m not holding it to any sort of standard that is what it is not matter how you dress it up to sound even a little cogent.

It’s just another unprovable and untestable claim just like simulation

That's the insanity of trying to prove it, on top of it being unprovable of course. — Darkneos

I thought I proved ... something. I quite like me proofs. :smile:

Don't throw the baby out with the bathwater.

You didn't. None of your logic followed.

It's not, you're just trying to patch it up to be something other than what it really is.

Like people said about my first post with that proof, it's nonsense.

Not to mention all this got way off track from my original post about whether the argument followed or was just nonsense.

Why do you think solipsism is something other than its manifestations? Because that is how it is conventionally understood? The convention is an illusion. Don't ask if the illusion is true, but if the convention is true.

It's not a convention, it's what solipsism IS. Period. Stop making it other than what it is, it's not working and getting off track.

Only I can prove solipsism true. By definition.

I'm not inventing anything: solipsism is classified as mental disorder, feral state, speculated state at infancy, and an individual/ subjective/metaphysical/ irrational state. It is the perception that one is the sole mind and origin of everything, but it is not that reality. It is like the simulation hypothesis. The simulation hypothesis causes us to question what is real, but it is not the likely reality. That we can consider the simulation hypothesis is a function of indirect realism, that we can think of things and have perceptions that do not reflect the physical world. Solipsism is another function of indirect reality but it is about the ego v. other minds.

...and there is the bias.

Only I can prove solipsism true. By definition. — unenlightened

...and then the need for a proof seems moot.

You didn't. None of your logic followed. — Darkneos

I intelligo.