I know I’ve asked a lot of these but this one I’m hoping to be definitive.

I have heard pretty much everyone say that it’s unprovable, that you can’t know for sure if it’s true or not because of the nature of the question. And that did bug me for a bit but I can accept that, some stuff in life is just like that.

But then I came across a post on Quora that at the time I strongly felt proved solipsism to be true. Though I don’t remember the post or question or what the answer said I just have a strong feeling that it proved it.

But I began thinking, since I can’t remember the content at all, how could anyone do that? I mean isn’t solipsism at best just uncertainty about the external world and other minds and at worst denial of anything but you. You can’t design an experiment to prove it because that would be trusting something other than your existence. When you doubt everything but yourself you can’t really prove your point to anyone else, right?

And I know people will laugh but I googled it and nothing came up about it being proven. Not a one. Just stuff saying you either can’t, or how it is consistent as a framework, but nothing proving it true. Which seems to lend credence to it being unprovable. I mean if in all the thousands of years of philosophy no one has done it then that kinda answer that question right? From everything I’m able to gather there isn’t a way to know if it’s true or not, it’s impossible.

Im just asking if this is truly the case. Yes I’m also aware of the irony of someone posting on the internet to someone’s question about if solipsism is true or not.

I was also under the impression that as a metaphysical position you can’t really test it or prove it, or is that wrong too about metaphysical positions.

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    Here is another question for you: does it really matter? For all practical purposes, whether you are the only mind in the world conjuring up a Matrix like fantasy, or whether there are other minds, it's all the same for practical purposes.
    – Frank
    Apr 2, 2023 at 23:07
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    And here is another thought: would there be an informal argument against solipsism from probabilities? if your mind is alone and really conjured up all that you see, hear, feel, ... there are many coincidences. Your mind is truly extremely powerful if it can reliably produce that very elaborate fantasy, which contains "others" that seem to come up to your consciousness "at random". Does that sound likely to you?
    – Frank
    Apr 2, 2023 at 23:09
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    "I have heard pretty much everyone say that it’s unprovable... From everything I’m able to gather there isn’t a way to know if it’s true or not, it’s impossible." How would someone saying the same thing one more time here make it any more definitive?
    – Conifold
    Apr 2, 2023 at 23:16
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    See this post Apr 3, 2023 at 8:38
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    If solipsism is true why come here ask other minds what they think about it?
    – armand
    Apr 3, 2023 at 10:43

5 Answers 5


Solipsism is unprovable because of the nature of our interactions with the world.

In simple terms, the idea would be this: We can never access the world "as it is". Even conceptually, that is a meaningless idea because our entire experience of the world is grounded in our systems of perception. These systems interpret and all we see is our own subjective interpretation. We cannot prove or disprove things outside of this interpretation because we have no access to things beyond this interpretation.

Or, in a more formal sense:

  1. We only have access to our own minds
  2. We don't have access to the existence of things outside of our own minds
  3. If we want to prove or disprove solipsism, then we'd have to prove or disprove the existence of things outside of our own minds.
  4. If we want to prove or disprove x, then we need access to it.
  5. Therefore, we cannot prove or disprove things outside of our mind
  6. Therefore, we cannot prove or disprove solipsism.

The Caveat

Now, that said, a lot of the time philosophy isn't about proving or disproving things. Rather, it's about the intuitive force and appeal of certain positions, the costs that come with them, and the evidence around them. Maybe solipsism can't be proven, but given our experiences is solipsism likely? Does it fit naturally within our metaphysical positions? What does it generate to?

Existentialist philosophers, for example, would reject lots of versions of solipsism because they claim that our existence is fundamentally an experience of the world. Heidegger would say that the existence of other people and the world is undeniably a structural part of being human, and therefore ridiculous to doubt. Sartre would say that the Other is an important part of what gives us identity.

Some contemporary philosophers claim that broad scepticism with solipsistic flavours are only academic, no one can actually genuinely believe in it as a position and so it may not be worth discussing. Others discuss different flavours of it when talking about other minds.

The Problem of Other Minds and general Sceptical Arguments might be a good place to start thinking about questions like these.

(For a similar debate about an unprovable question, look at the Problem of Evil. The debate here also quickly moves on from, "can we prove x?" to "what are the implications of x? Is x likely? etc".)

  • That seemed to be my first response when I thought they proved it. Not only can you not read minds but to prove solipsism true would require omniscience. We cannot get outside of our own heads so anyone claiming to have proven solipsism true would be wrong. Even if we could get out of our own head that would likely still lead to the same issues about whether we can tell it’s real or not.
    – DarkNeos
    Apr 3, 2023 at 15:03
  • Yep. The problem is fundamentally about our access to the world. Usually proofs for solipsism or proofs against it are more arguments grounded in assumptions. For example, Descartes arguments in Meditations are largely grounded in assumptions about the nature of God. Apr 3, 2023 at 17:32
  • So even if someone “proved it true” it would still be resting on assumptions that they cannot test right? I mean I’m comfortable with being unsure as I can just dismiss it after that point. It goes back to what I was saying, you’d need omniscience to prove it true or false because only then could you have utter certainty of your perception.
    – DarkNeos
    Apr 3, 2023 at 21:27
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    Well, either assumptions they cannot test or assumptions that are potentially unsound (i.e. just wrong). You're right, you need omniscience to prove it. Apr 3, 2023 at 22:43

I cannot disprove that there is a planet in Andromeda populated by clones of Marilyn Monroe- does that mean I should believe it? There are countless unprovable ideas, but the fact that an idea cannot be disproved does not necessarily make it credible. Extreme forms of solipsism are clearly nonsense, notwithstanding the fact that it might be impossible to disprove them. One can, of course, point out no end of ludicrous implications of extreme solipsism. For example, it is clearly inconsistent, in that the solipsist's mind imposes all kinds of limitations on the ability of the solipsist, and yet it allows the solipsist to imagine people speaking Chinese, calculating pi to n-trillion decimal places, inventing General `Relativity and performing no end of other activities which the solipsist himself is entirely incapable of performing. But no amount of common sense argument is sufficient to satisfy the committed solipsist, who, in that regard at least, is certainly not alone in the world of philosophy.

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    Yes, the idea that one's mental creations could be smarter than oneself seems like a deal breaker. But sometimes I do have experiences of a character in a dream solving a problem that I couldn't, or a personality character (like in a book I am thinking about and writing) solving problems in waking life. Minds are pretty amazing.
    – Scott Rowe
    Apr 4, 2023 at 10:34
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    @ScottRowe I know what you mean. And after all, it would be hard for me to imagine someone smarter than myself! Apr 4, 2023 at 10:56
  • But what if this alleged Quora post did manage to prove it true.
    – DarkNeos
    Apr 4, 2023 at 16:21
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    @DarkNeos if the post did prove it true, then you do not exist and I would be led to the contradictory conclusion that neither did the person who penned the post, therefore they could not have proved the point that led me to assume their non-existence. Apr 4, 2023 at 20:54
  • @MarcoOcram So even if they allegedly did it wouldn’t be something that could be trusted or verified right?
    – DarkNeos
    Apr 5, 2023 at 20:01

I would differentiate between epistemological solipsism (I am certain only for my existence, a-la Descartes) from metaphysical solipsism (I am the only thing that exists).

One does not necessarily lead to the other. Even Descartes (Meditations) started from epistemological solipsism yet arrived at realism.

One can doubt the premise of epistemological solipsism as well (eg we are equally certain of other things besides ourselves. In the same sense I know for certain what is "me", I can know for certain what is "not-me" and I perceive things which I know they are "not-me", since I know what is "me").

In any case, metaphysical solipsism is easier to counteract. Metaphysical solipsism is the thesis that only "I" exist (sole ipso) and everything is either my creation, or is experienced because I am its ultimate purpose (being the only thing existing). It is hard and highly problematic and incoherent to phrase metaphysical solipsism differently.

This thesis necessarily makes the subject omnipotent, either directly (as creator) or indirectly (being the ultimate purpose of everything).

We are demonstrably not omnipotent, thus metaphysical solipsism must be false.

Once one doubts metaphysical solipsism, epistemological solipsism can follow, since we now necessarily know there are other things (besides ourselves) that exist as well

Hope these help.


Personally I prefer to view things in terms of weighing reasons rather than in terms of proof. Strictly speaking, nothing can be proved to be true or false except logical and mathematical theorems. The point, then, is rather if solipsism can be justified or not, whether there are good reasons to be a solipsist, and less good reasons not to be one. And, I don't know for you, but as far as I am concerned the evidence against solipsism seems overwhelming.

If there was nobody around, I would have good reasons to be a solipsist, but there are many people on earth. If I could easily control the phenomena I experience too, or if there were no contingencies, but many things that happen to me were unpredictable and outside of my control. If other people were very distinct from me, if they were not expressing emotions, maybe I could think that they are sophisticated automats or artefacts of my consciousness, but other people are more or less like me. Or if I could witness evidence that people are merely pretending to be conscious and switched behaviour when they think I'm not here, for example, or if there were inconsistencies in what I take to be reality, I would have reasons to doubt, but I haven't witnessed anything like this so far.

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    +1 "Personally I prefer to view things in terms of weighing reasons rather than in terms of proof. Strictly speaking, nothing can be proved to be true or false except logical and mathematical theorems." And even then, a constructivist rejects some proofs a non-constructivist accepts begging the question of whose theory of proof, if any, is best?
    – J D
    Apr 12, 2023 at 22:48

No, some arguments to unprove Solipsisim are:

1. Wittgenstein's “Private Language” There is no such thing as a “private language.” We learned the language we use to think with. We did not invent our “native” language, or our “1st language.”

Imagine trying to invent a whole private language, even putting aside not having anyone to communicate with through it. Who would understand it?

The best explanation of the fact of language is that through an historical process other minds created and transmitted language to us.

So there are other minds.

Credit: Lou Reich

2. Problem of Other Hemispheres / Split Brain

The sceptical Problem Of Other Minds will be solved by biotechnology. Compare people born without a corpus callosum to connect their cerebral hemispheres, or “split brain” patients who’ve had their corpus callosum surgically severed to treat epilepsy. If one hemisphere entertains doubts whether the other hemisphere is really conscious (aka the Problem Of Other Hemispheres), then currently the sceptical hemisphere can’t prove the sentience of its twin. However, advanced biotech promises corpora callosa grown to order, laying sceptical doubts to rest. More radically, artificially-grown corpora callosa and reversible thalamic bridges will let neurotypical humans partially “mind-meld” like the conjoined Hogan sisters today. So yes, solipsism can, in principle, be scientifically disproved.

Credit:David Pearce


3.Sartre's Emotion Argument

Sartre held that the feeling of shame proved solipsism, and idealism to be false. If we are caught peeping at someone undressing in the toilet then we feel ashamed. If solpsism or idealism were true, this feeling would be false. But since we all have this feeling at one time or another Sartre held that there must exist other conscious bodies. The trouble with this is it reduces proof to emotion. It then follows that our opinion of what is real reduces to how we feel about it.


Heidegger and Sartre on the Problem of Other ... https://philarchive.org/archive/CAOHAS

Credit: Andrew j. Turner

4.Quantum Mechanics

The key point is that a realist explanation of quantum experiments requires the existence of something directly represented by the quantum state or something that can simulate the quantum state,while the mental state is a classical state in the sense that it is always definite and its content contains only information about macroscopics ystems such as the setting of apreparation apparatus, which is not enough for representing or simulating the quantum state. A positive result of this analysis is that one finds the existence of anexternal world besidesone’s mind.

Quantum mechanics refutes solipsism:A proof of the existence of an external world https://philsci-archive.pitt.edu/22361/

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