Is solipsism truly unprovable?

Question

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.

Answer 1

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".)

Answer 2

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.

Answer 3

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.

Answer 4

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.