My philosophy professor once told our class: The only people who believe in solipsism are infants and madmen. I was inclined to agree at the time. Yet years later, I have still not encountered any good arguments to disprove this idea.

Thus, I am curious—is this question of the same ilk as the "free will vs. determinism" or as the previously asked on this page: How does one know one is not dreaming? Or is there a compelling argument that leads to a logical rejection which can reinforce my "intuitive" rejection of this idea?

I can see how direct disproof may be impossible, so I believe that answers could be open to weaker arguments such as ones of utility that relegate solipsism into such a useless corner that for one to hold such an idea would be counter-productive to rational thought.

  • Can we get some more context? Maybe describe your understanding of what solipsism means, what criticisms you've heard already and why you remain unpersuaded, etc.
    – Joseph Weissman
    Commented Jun 10, 2011 at 2:10
  • @Joe I suppose an edit may be order- by solipsism I refer to what is defined in wikipedia as "metaphysical solipsism" en.wikipedia.org/wiki/Metaphysical_solipsism that is the idea that ones own mind is the only thing that has any real existence or to quote: "the self is the only existing reality and that all other reality, including the external world and other persons, are representations of that self having no independent existence."
    – user151
    Commented Jun 10, 2011 at 2:16
  • @Joe and as to why I remain unpersuaded: this idea just does not jive with my acceptance of history- that is the story of the world before I existed
    – user151
    Commented Jun 10, 2011 at 2:18
  • @jaskey13 What does "believe" mean? Certainly, solipsism is not a good world model to get peacefully through everyday business, but it is perfectly possible to believe in one thing, but pragmatically live according to another thing. (E.g: I can be convinced that life is totally meaningless, but think that I am happier if I talk about life as if it had meaning.)
    – Phira
    Commented Jun 10, 2011 at 8:15
  • 1
    Your professor was poorly informed. A popular and ancient explanation for the unfalsifiability of solipsism is that it is not strictly false. This is called mysticism. If you manage to falsify solipsism you will win fame as the person who proved that the Perennial philosophy is nonsense. Kant called our inability to falsify Solipsism the 'scandal of philosophy' and so it is if we cannot explain it. It's a good question you ask since this issue deserves a lot more attention than it usually receives and it's a productive problem to work on. . . .
    – user20253
    Commented Mar 8, 2018 at 11:40

12 Answers 12


I would compare it to someone believing that if a tree falls in a forest and no one is around to hear it, it does not make a sound.

The definition of the question limits us to not being able to answer it, and both silent-tree-believers and solipsists opt for the most sceptical position, that is opposed to our common sense understanding of the world.

Our model of the world is based on imperfect information, and we constantly make inferential leaps. Most of us believe that we aren't dreaming, that when things are hidden behind obstacles they are still there, and that the sun will rise again tomorrow. Most of us also believe that other minds exist.

This series of assumptions turns out to be a really useful model for understanding and predicting our environment, and modifying our behaviour to meet our ends.

The fact that these cannot be proven, does not mean that they are false, or that it would be beneficial to consider them false.

One can say that they are not sure, and indeed, some versions of solipsism state simply that the only mind's existence the individual is sure of is their own. This really doesn't go very far, as at this level of scepticism, there's very little to be sure of at all - maybe each 'instant' we're recreated in a totally new world with a different history, and our memories and identities are fabricated.

I think the reason solipsism seems more important to argue against than a disbelief in e.g. object constancy is rooted in our conception of 'the ghost in the machine' and the mind-body problem. We're rather self-centred.

Some background and historical arguments:

Solipsism is a world view extrapolated from the problem of other minds. Simply stated, the problem of other minds is that we cannot know (or prove) that others have minds like our own.

The Stanford Encyclopaedia of Philosophy has an in-depth article about it. It presents a series of solutions to the problem (and by extension, to solipsism). The following is the uncomfortable conclusion:

This article has been almost entirely concerned with the epistemological problem of other minds. What generates the problem has been carefully delineated. The standard solutions have been outlined and the various critical responses discussed. What is clear is that there does not seem to be what might be called a received solution to the problem. It has been argued that the problem cannot be removed, nor can it be made easier to solve, by embracing any particular philosophy of mind.


As you note, there can surely be no solid rebuke of solipsism, for the possibility is wholly untestable. However, I personally believe solipsism is bordering on incoherence and egoism, and exploring what it would really mean if all of existence as we know it was solely for us or perceived by us may help demonstrate that. Two possibilities arise:

1: The universe is some sort of simulation or model, all beings we perceive are merely agents of that system, and we are the sole target of the simulation. All of existence, therefore, is created for our benefit. We must then ask, why? Why are we so special as to merit all of this? And furthermore how? How, despite being special, are so many millions of mindless agents able to function in a way that I am unable to distinguish them from myself?

2: The universe exists largely as we are taught in school, the big bang, atoms, molecules, evolution, and the whole shebang, and yet we are the only being that actually experiences or "lives" - we are the only being with a mind. This should similarly raise some alarming questions, why do we have this ability, and yet all others do not? And again, how is it possible that we are so fundamentally and critically different from all other beings in the universe, and yet we cannot identify a difference?

To me, both cases seem highly implausible. Unprovable, but does it not seem very strange to think that either of these situations are how existence "really is"? Personally, the alternatives, that either 1: we are part of a simulation or other matter-less existence (like Berkeley's idealism) wherein the beings we perceive as similar to us are in fact thinking minds like us, or 2: the physical world exists largely as we understand it, and therefore again, things we perceive like us have reasonably similar mental states.

This is somewhat related to the philosophical theory of Functionalism, which could be vulgarly summarized as "if it walks like a duck and talks like a duck, then it's a duck!" which might be a more robust response to solipsism than most other philosophies.

And, now that I've discussed why I think solipsism is bunk, let me share with you this wonderful short story, The Egg, it's a beautiful perspective on solipsism, and no matter how many times I read it, I get chills and a little smile every time I get to the end. I hope you enjoy it.

  • I would say the the second possibility is a very suitable idea to resolve numerous mind-body paradoxes. Namely if one asks which beings can experience qualia, the only possiblity is to draw the line around oneself. Any other approach (draw a line between humans and other animals, between animals with and without brain, between animals and plants, claim there is no qualia at all etc) would lead to further paradoxes.
    – Anixx
    Commented Sep 15, 2011 at 0:16
  • 1
    That's a fair point - it seems highly implausible, like I said, but it does resolve many philosophical challenges if it's true. You should look into Bishop Berkeley and his Treatise Concerning the Principles of Human Knowledge, I suspect you'll like it.
    – dimo414
    Commented Sep 15, 2011 at 13:43
  • And also a claim that we cannot identify a difference is doubtful. Both from subjective point of view (direct experience of qualia), but also from a point of view of natural science. For example, existence of a distinguished observer considered a non-desirable (but inextinguishable) consequence of several interpretations of quantum mechanics. Non-desirable because existence of such observer undermines the scientific method and the purpose of science to serve all people.
    – Anixx
    Commented Sep 15, 2011 at 13:51
  • I think you're taking me too literally. From a layman's perspective, we behave as if the people we interact with are like ourselves, both externally and internally. Although this is not enough to resolve the question of solipsism, as you point out, it is still worth remembering. My challenge is one of likelihood, not of possibility. "How is it possible that we are so fundamentally and critically different from all other beings in the universe, and yet we cannot identify a difference?"
    – dimo414
    Commented Sep 15, 2011 at 14:07
  • @dimo414 I may have misunderstood you, but Berkeley didn't endorse solipsism; rather, he endorsed idealism. Yes, it's easy to go from idealism to solipsism (the coordination question), but that's where God came in. Still, it did resolve a lot of things, and I think his views don't get the respect they deserve.
    – R. Barzell
    Commented Feb 28, 2015 at 21:12

Not a rebuttal, because solipsism is unfalsifiable anyway, but in On Certainty, Wittgenstein shows that in order to survive solipcists have to act hypocritically. Although they will profess they have their own reality or they even just dreamed you and every other people around them, they won't act like it is true. They will continue looking for food, friends, entertainment, go to sleep. Their day to day interactions with other people require them to act like they share our common reality, like those people they pretend to have imagined actually did something when they are not there to watch.

A solipsist who really believes can't be a functional member of society, and in the other hand every functioning member of society who pretends to be solipsist is only pretending.

  • "About Certainty?" When did he write that?
    – gonzo
    Commented Jan 11, 2021 at 0:54
  • My bad, the correct English title is On Certainty. He wrote it just before his death.
    – armand
    Commented Jan 11, 2021 at 1:00
  • He did, didn't he (I was pulling your leg, my friend)? Or at least he wrote the notes that were compiled into it by Anscombe and Wright. You've read it have you? Tell me about how it " shows that in order to survive solipcists (sic) have to act hypocritically." Be specific.
    – gonzo
    Commented Jan 11, 2021 at 3:44
  • How about you read the book and share your interpretation ?
    – armand
    Commented Jan 11, 2021 at 3:58
  • It is likely that I read the book before you were born, my friend. I've not made any claims about the book, so I have nothing to defend. You want me to tell you waht a hinge is, how it differs from the synthetic a priori? What? Nevertheless, you might appreciate this: philosophy.stackexchange.com/questions/78482/…
    – gonzo
    Commented Jan 11, 2021 at 4:16

While it may seem superficially simpler to assume one mind rather than many, it requires a fairly complex story to explain why the one existing entity perceives the apparent existence of many entities.

It also requires an explanation of the distinction between the real and the apparent existence of external entities --in other words, if I interact with you, and you exhibit all perceivable signs of being a real, external entity, then by what criterion am I justified in denying your real existence?

Therefore Occam's Razor actually weighs in against solipsism.


I came up with this reasoning, made some points clear from my perspective, but it still does not disprove solipsism, rather weaken it:

  1. Accept that "my" quale is the only thing that exists.
  2. There also are other beings, which my mind makes up that they have their respective qualia.
  3. Then "I" should have some degree of control of, or access over theirs. If I fail to do so, then there is some "thing" that prevents myself from accessing it. That is, I cannot totally make everything up.
  4. This implies that the only entity is not my quale, but some other omnipotent entity that creates this experience. Not "I", but "it". But even then, there is my quale which "experiences" its reality. So this "entity" and "I" happen to be merged. However, there is still some distinction, even if it is illusionary, that makes it not "sole".

This reasoning weakens solipsism, but you can still evade it with the argument that it is reached with a logic that you made. This is what makes solipsism arguably not disprovable.


This is quite old, but as I was having a discussion on Solipsism with a few friends of mine, I independently came up with what I feel is the best way of "disproving" Solipsism. Obviously, the concept is defined so that it cannot be proven or disproven inherently, and I believe others have come up with the same kind of argument against Solipsism.

  1. Assume that Solipsism is true
  2. Thus there must be an objective Solipsist mind ("It")
  3. But, "I" observe objects and minds ("They") that "I" perceive to be external
  4. Thus, "I" am a subset, or an aspect, of "It"
  5. Likewise, "They" are aspects of "It", and "I" and "They" are mutually exclusive
  6. If "I" and "They" are merely aspects of "It", "I" am not "It"
  7. Therefore, "They" are external to "I"

Now we have a disproof by contradiction.

Solipsism is thus isomorphic to Pantheism, as "I" and each member of "They" are aspects of "It".

Unfortunately, this is really just a semantics game. What exactly am I? Am I my conscious mind and subconscious mind, or am I my conscious mind, and I am influenced by my subconscious mind? Solipsism cannot be disproven, but to even be considered, it requires many more axioms to explain why certain things happen, and a rigorous definition of the self ("I").

  • It's a nice argument, but I don't think it's as damning as you imagine for the solipsist. It would work against a type of monistic solipsism that cannot distinguish between thinking part and thought part, but it's easily subsumed by identify the I/They distinction as a distinction between parts of the I -- with the observing bit doing the thinking and the observed bit receiving it.
    – virmaior
    Commented Mar 1, 2015 at 7:01
  • Agree completely. The whole argument is based on an assumed definition of the self.
    – Esaron
    Commented Mar 2, 2015 at 15:49
  • 1
    This doesn't work to disprove solipsism because a core tenet there is the admission that your subconscious mind (the one that contains the information on the entire universe, including what we perceive as "other minds" is somehow hiding all this information from your conscious mind and making you learn information consciously and through your 5 senses only. The better question in my mind is - Why?
    – LightCC
    Commented Dec 15, 2015 at 18:27

Make up two numbers in your mind. Grab a calculator, add them. Note the result. Add the nimbers in uour head (adding them should be tricky enough so that you can’t know the answer in an instant). If the calculator was faster than you, what ever force is behind the calculator cannot be a product of your immagination.

  • To argue on the same level, one could say: Imagine you were to do this while sleeping/in a dream. Would you think, that the calculator being faster at calculating gives you any evidence for whether you're dreaming or not? Commented Apr 2, 2021 at 22:33

You don't really need to know where your sensations come from. You still know they exist. Solipsism is partly true in the sense that many of your sensations (colour, false memories etc) are invented.

From Harry Potter and the Deathly Hallows:

Harry: "Is this real? Or has this been happening inside my head?"

Dumbledore: "Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?”

The method used by Descartes was to imagine a perfect being, an un-stop-able being (not stopped by any kind of argument). You can be sure that your idea of this being exists inside your head. But because it is unstoppable, it must also exist in reality.


If the solopist dies and you are still in existence then by Jove you have refuted solopism. Now to find a solopist that is not dead yet, be careful around this person. When he goes so do we.


There is no way of proving the negative. It's pure demagoguery to assert that one cannot disprove solipsism therefore the empirical universe exist only as the figment of the imagination of the person making the claim.

Description: Demanding that one proves the non-existence of something in place of providing adequate evidence for the existence of that something. Although it may be possible to prove non-existence in special situations, such as showing that a container does not contain certain items, one cannot prove universal or absolute non-existence. The proof of existence must come from those who make the claims.

Logical Form:

I cannot prove that X exists, so you prove that it doesn’t. If you can’t, X exists. Example #1:

God exists. Until you can prove otherwise, I will continue to believe that he does. Explanation: There are decent reasons to believe in the existence of God, but, “because the existence of God cannot be disproven”, is not one of them.

Example #2:

Sheila: I know Elvis’ ghost is visiting me in my dreams. Ron: Yeah, I don’t think that really is his ghost. Sheila: Prove that it’s not! Explanation: Once again we are dealing with confusion of probability and possibility. The inability to, “prove”, in any sense of the word, that the ghost of Elvis is not visiting Sheila in her dreams is an impossible request because there is no test that proves the existence and presence of a ghost, so no way to prove the negative or the non-existence. It is up to Sheila to provide proof of this claim, or at least acknowledge that actually being visited by Elvis’ ghost is just a possibility, no matter how slim that possibility is.

Exception: If Ron were to say, “That is impossible”, “there is no way you are being visited”, or make some other claim that rules out any possibility no matter how remote (or crazy), then Sheila would be in the right to ask him for proof -- as long as she is making a point that he cannot know that for certain, and not actually expecting him to produce proof.

Tip: If you think you are being visited by aliens, gods, spirits, ghosts, or any other magical beings, just ask them for information that you can verify, specifically with a neutral third-party that would prove their existence. This would be simple for any advanced alien race, any god or heavenly being. Some ideas of things to ask for:

future lottery numbers (of course you will give all your winnings to charity) answers to scientific problems that do have scientific answers, but aren’t yet known exact details of major future events But if these beings just tell you things such as:

passages / ideas from the Bible whether you should take that new job or not where you left your car keys that they really exist, and others will continue to doubt you that you should never question their existence ...or anything else which is just as likely to come from your imagination that is untestable and unfalsifiable, then you might want to reconsider the fact that your being of choice is really paying you visits.


You Can Prove a Negative. (n.d.). Retrieved from http://www.psychologytoday.com/blog/believing-bull/201109/you-can-prove-negative


There are two arguments which I think work to slightly reduce the strength of solipsism. The first I’ll term “madness argument”and the second which I’ll term the “new information argument”.

Madness argument:

  1. The solipsist will argue that because I only experience my own conscious mind, my conscious mind is the only thing which exists.
  2. To make this argument, the rule of logic must hold in order for my argument to be true
  3. In order for me to be able to make the argument I want to make, I must concede that the rule of logic would hold whether or not my mind existed, otherwise I am admitting that I am just saying meaningless words, and so I cannot make my argument.
  4. If the rule of logic holds irrespective of my mind, it means that my solipsistic existence is predicated on the existence of an external set of laws, which is self destructive.

New information argument:

  1. Across time, I often experience entirely new information which I was simply incapable of conceiving before it appeared. Eg a a new colour.
  2. Something external to my conscious mind introduces this new colour because I am totally unaware of its existence (even if that’s simply my ‘extended mind which comes up with all the stuff which it will feed to me later but to which I’m not yet privy to sensory experience’ )
  3. Therefore there’s something outside of my mind.


  1. You might argue against this by saying that flow of time doesn’t exist (so no new information, only a snapshot frame) and existence entirely consists of a single split second moment of my consciousness, where past is just false memory.
  2. If that’s the case the argument breaks down because it’s not possible to make an argument without being able to go through premises and conclusions, which require time (even if small).

Are there any philosophical arguments to disprove or weaken solipsism?

Solipsism is a misleading word. It suggests that there is a theory which could conceivably be true of all minds, but of course there isn't. A solipsist mind believes there is no other mind, and therefore no other mind to convince that there is no other minds. He or she has no motivation to convince anyone because he believes there is no one else, and therefore no one to convince.

Thus, all that there might be is a solipsist person, a person believing that his or her mind is the only thing that exists and that the whole of reality is just an idea inside this unique mind. Assuming such a person really exists, he or she is not going to possibly convince anyone that they are mere fictional characters inside his or her mind. So, essentially, there is no argument to be had.

Something else is to say that a mind does not actually know anything outside itself, and can therefore only believe that there is a real world outside itself. As such, this does not say that a mind does not believe that there are other minds. Indeed, this seems to be what all minds believe. This theory, however, does explain how it might be possible to be a solipsist, since if it is possible to believe there is a world outside your mind and other minds with it, it must be possible to believe that there is no world outside and no other minds. If a mind knew other minds, or knew that there are other minds, it would be impossible for it to believe it is alone and to be a solipsist. Still, while it cannot be excluded that there exist solipsists people, it is unclear that anyone could actually live a life as a solipsist.

The idea that there may be solipsist people seems to have been offered as a way to help us think about the epistemological status of our own mind. this idea does not need to be falsified, it only needs to be pondered.

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