The problem with explanation "my subconsciousness just made it all up" is that there is no definition of what "your subconsciousness" means. If we are going as far as denying the existence of the entire universe, then even "well, then your subconsciousness would need greater computational capacity than the entire known universe" is not a meaningful objection, because the entire known universe, maybe even math itself, are just things your subconsciousness made up.
In other words, solipsism only works because you not-define the subconsciousness. Whatever objection anyone can make, you are free to expand your non-definition of "subconsciousness" to include it.
An equally meaningful philosophy would be that the universe is a cabbage. Not an ordinary cabbage, of course (please don't strawman my supreme philosophy!), but a special magical cabbage, which magically has exactly those properties it needs to have in order to explain all available evidence. A universe-simulating, consciousness-containing cabbage. Can you disprove this?
Indeed, since there is no absolute distinction between the parts of reality that are 'you' and those that aren't, then solipsism isn't by itself a meaningful concept.
One of the challenges with solipsism or any claim about metaphysics is that we lack access to evidence to settle disputes about it (once we steelman what we mean say it's not obviously false). In this sense, it's something we can imagine but cannot justify. Same goes for alternatives to solipsism, like physicalism.
So there's not much to say here. You can't prove it disprove solipsism by our normal epistemological methods because it hinges on information we can't have.
I think you need to formalize what claims are being made by "solipsism" in your discussion. There are a number of possible interpretations, some more justifiable (and less interesting) than others. The simplest form, that everything you know about the universe is what you've perceived, is pretty straightforward. Stronger forms, like denying that anyone else exists because you can't perceive their conscious experience, only your experience of something that you interpret as their behavior, are less obvious.
I think then you need to define "prove" in any meaningful way. Generally, this is a definition or modeling choice, not a testable prediction, so "true" or "prove" don't have much utility in the discussion.
Also, beware discussions with pragmatic philosophers - the best argument against a solipsist is a hard punch in the nose and then ask them why they hit themself. It doesn't add any knowledge to either side, but it does stop the debate.
I arrived at your page because I was looking for a way to talk to people about the difficulty of knowing if you’re awake or dreaming. Almost everyone assumes it’s quite obvious - dreams are, well, dreamy, details aren’t filled in, etc. It seems to me that none of the arguments I hear against solipsism would be helpful in the solipsistic state of false awakenings.
It seems that most people are not familiar with the experience of repeated false awakenings (that is, you “wake up” and assume you’re awake, but something odd happens and you realize you were still dreaming; in a series of such false awakenings, it may happen 4, 5 or more times)
I’ve never heard an argument that would actually be helpful in a series of false awakenings. If I met you in one of those dreams, none of your arguments would help me. The whole idea “if I’m talking to you it means I “believe’ there’s someone else” wouldn’t help at all. Many times, I’ve had false awakenings where I’ve talked to someone and told them I wasn’t sure if I was awake or dreaming. They assured me I was awake, and then I’d actually wake up and realize it was a character in my dream I was talking to.
Another common statement is “Well, if you’re questioning whether you’re awake or not, you must be dreaming.” I can only assume that people who say this have never had a VERY realistic series of false awakenings.
Quite often, on the 4th or 5th apparent awakening, you’re still questioning, looking around, not sure whether or not you’re dreaming. In one case I had not so long ago, it was at least 5 minutes before I was convinced I was actually awake - and I was quite intensely questioning everything I experienced during that period that turned out to be a wakeful one, not a dream.
Recently I came up with another approach which I found gave people more of a concrete sense of why it’s so difficult to discern the difference. I referred to Bertrand Russell’s experience of having what he claimed were nearly 100 sequential false awakenings.
Russell is widely recognized as one of the great mathematicians of the 20th century, at least a well respected philosopher, and is also known for his refutation of solipsism.
So obviously, no philosophic argument was able to help him when he was in the midst of his 20th or 60th false awakening.
So I’d love to hear - is there anything you can think of that Russell hadn’t thought of, that you think could have helped him determine if he was awake or in the solipsistic state of dreaming?
I had a discussion with a find of mine via text messaging on whether solophisim can be proved or disproved. The conversation went a somewhat off track, but I believe it produced some conclusions that would be of interest to others. I shall refer to my friend as Thomas Aquinas. The conversation started with the following text message from Thomas.
The last two message is the impetus for this post. TA has made a very eliquoent formulation of solipsism. He is revealing his religious beliefs in stating that the non union is "non-hypostatic", but I believe this applies to any formulation of God. As for TA's NDE, he told me his NDE caused him to "disolved into an infinite number of senses, all like sight, sound, taste, and touch, only each different." He said that after that experience life felt like "watching a colorless motion picture". Curiouser and curiouser..