Computational counter-argument for solipsism



First let me elaborate the argument.

  1. Take a calculator (wolframalpha, google or other software tools may serve as well).
  2. Perform some very complex operation.
  3. Write down the operation and the result separately.
  4. Go do something fun for about 10 minutes.
  5. Take the paper with the operation.
  6. Try to calculate the result.
  7. Make sure it's right, we will wait.
  8. Now check with the result you had before that it is right.
  9. Both results match, but one took much longer to be calculated.

The point is: If the first result (produced by the calculator) had been produced by your mind emulating a calculator then the second result, produced by your mind with no emulation involved would have been obtained in less time, due to a greater access to the raw processing power from which all calculations stem, your mind. Therefore that option is discarded by reduction ad absurdum.

However, it takes longer for your mind than for the calculator, which means that the calculator must be powered by a different piece of hardware (than that of your mind) which allows it to perform such complex calculations in less time. The calculations are really being done and they are not an illusion because the results match. Therefore we can know we exist (cogito ergo sum) and that there is at least one other thing that exists, which thinks faster than us (at least sometimes).

Now the questions:

  • Is this really a counter-argument for solipsism or did I fail at some point?
  • Does this refute solipsism or is it not such a strong argument?
  • Has someone proposed this before? (I really doubt I'm the first one thinking this, but I have no clue about how to search for it in the state of the art).

Thank you.


Posted 2014-01-23T10:59:25.117

Reputation: 634

Question was closed 2016-01-04T20:13:20.517

1How do you know, in acting as though you are trusting some external entity, that you aren't relaxing and accepting the answer which some recess of your unconscious mind is producing? Supposing that you grant, as a solopsist, that you grant that "you" are a phenomenon which is complex enough to extend beyond your own immediate conscious sensation, that is. – Niel de Beaudrap – 2014-01-23T11:16:24.880

@NieldeBeaudrap Either: a) I can access that unconscious-me and perform the calculations as fast as the calculator (the initial hypothesis turns false, I'm just as fast), or b) I cannot access that unconscious-me which is then effectively a separate entity from myself conscious-me (the conclusion turns true, there is a separate entity). – Trylks – 2014-01-23T11:42:22.673

1If you are an aspiring solopsist, how can you be sure that you have not been conditioned (not by anything external to you, but just a fact of your existence) to think that you don't have such powers — and that you must first overcome the conditioning to consciously choose to access these powers (without relying on apparently-external agents)? And if you have such conditioning, can you be sure that it can ever be overcome? I don't see how to rule out this possibility, unhelpful a hypothesis as it is — but if we reject unhelpful hypotheses, we need not consider solopsism in the first place. – Niel de Beaudrap – 2014-01-23T11:59:20.997

@NieldeBeaudrap as long as this conditioning is not overcome my existence will be effectively fragmented into two separate entities and I would say that the "unconscious-me" that makes for everything in the universe isn't really me. If the conditioning is ever overcome, then the two fragments will join into one and the question whether there is anything else (but this unified fragment) will arise. If we play with the definition of "me" we can get to a pantheistic approach, where the whole cosmos is a god and we all are one being (god). A conscious notion of "me" is what makes sense here, IMHO. – Trylks – 2014-01-23T14:20:10.100

@NieldeBeaudrap my point is that basically that your ideas/arguments/insert-name are not related with the (in)existence of a "real" world, but with the boundaries of the definition of "I". Cogito ergo sum works because there is a subject "I", who thinks, but the limit of "I" is what is perceived as "I", what can be controlled as "I", what I can do. If we play with the definition of "I" then everything can be part of it, but still if you eat I'm still hungry, so it may be that you are an hallucination, a creation of my mind, but for sure you are not me. – Trylks – 2014-01-23T14:26:36.080

Then why worry about explicit computation? Isn't the fact that you can have conversations with people whose responses you can't anticipate enough? And on this basis, surely the corpus of Monty Python's Flying Circus is an irrefutable argument against solopsism, except just perhaps for the actual members of Monty Python, as writers of the show. – Niel de Beaudrap – 2014-01-23T14:27:58.417

@NieldeBeaudrap When I dream I have conversations that I can't anticipate. When I think I have thoughts that I can't anticipate until I have produced them. But they happen at "normal speed", the time the thought appears to my mind and my ears is basically the same. The computation is not completely unpredictable, but somewhat predictable. The point is the time that it takes to be done, which is a completely different aspect. – Trylks – 2014-01-23T14:32:26.043

Then, you find it reasonable to grant a split consciousness for dreams and conversations, in that somehow you are producing stimulus for yourself which you cannot entirely anticipate, but not for computations? Do you not find people's personalities (or the apparent rules of the universe around you) more-or-less consistent --- or at least as consistent as your own ability to make computations without errors? I think that your same argument can be applied to solopsism without having to concern yourself with computation. If you find the distinction important, you should note this in the question. – Niel de Beaudrap – 2014-01-23T14:37:26.457

My point is in the time that making a verifiable computation takes inside my mind and outside my mind (or the part that I feel as me, if you want to play with definitions). Perceiving people's personalities or the rules of the universe takes exactly the same time in a fictional world or in a real world. It's not about what you perceive, but about what you can think/compute. I don't understand what distinction should I note in the question. I don't get your point, which could be an argument, if I ever get it. I'm not sure whether that will ever happen, with a calculator I am certain. – Trylks – 2014-01-23T14:46:27.760

If the world rarely surprises you, or if the surprises seem like departures from consistency, then perhaps difficult computations are the most likely place to find such surprises. However, I find that they are just a special case of a very broad class of surprising features of the world which seem to hold together with the other things that I know. – Niel de Beaudrap – 2014-01-23T15:04:08.003

Surprises are not a good argument because my own thoughts surprise me just as much as the world, I have never thought any new thought until I think it, and then it surprises me as much as I could be surprised by seing something I've never seen before. Again, it's not about surprises, it's not about perception (of inner thoughts or outer events), it's about what you can think/compute and how long does it take. It's not a dot (perceive) but a path (calculate). – Trylks – 2014-01-23T15:18:36.283

I want to add two comments : (i) I think that, in terms of "logical foundations" for certainty, is very difficult to do a better job than Descartes. So, first of all, try to read and understand in deep Descartes. (ii) About "absolute foundations", XX century thought and science (e.g.foundations of mathematics, quantum physiscs) has shown - in an unprecedented way - that every "argument" must start from something : we cannot build a theory, a theorem or a philosophy absolutely "form scratch". 1/2 – Mauro ALLEGRANZA – 2014-01-24T13:30:02.503

So, whenever we will try to find a "definitive" argument for or against something (e.g.solipsism) we are bounded by some assumptions (explicit or hidden) : so the argument can be refuted simply denying some of its assumptions. So, simply, there are no "silver bulletts" in human thought: no absolute "whatever". – Mauro ALLEGRANZA – 2014-01-24T13:32:47.517



It is logically possible that you can in fact calculate that fast but you need the ritual of submitting the problem to a computer in order to be able to consciously access the answer. You can take this to ridiculous extremes by having mathematics formulas generated from block-codes from Bitcoin mining, with the calculation done without you observing, and only then you getting to check that the answer agrees with your longhand result. (I.e. you are either doing the entire world's bitcoin mining operations in your head, or your perceptions are not stable in that the answer changes between when you first read it and when you re-calculate and see if it's a match.)

However, empirically it suggests that (at least metaphysical) solipsism is a non-functional model of the world and should be abandoned. There are many other actual and thought-experiments which suggest the same. (E.g. falling in love with someone who is not interested in you.)

Rex Kerr

Posted 2014-01-23T10:59:25.117

Reputation: 15 388

You could do the same thing with any technology. I can't fly but I can take an airplane. But I don't know how to invent an airplane. Ergo there must be other people. – user4894 – 2014-01-24T04:27:54.020

Not really, the airplane could be in its insides made of cheese, and all would be powered by your imagination (there are airplanes in your dreams as well, right?). The calculator provides a hard fact that can be verified, the result. – Trylks – 2014-01-24T10:57:46.577

@RexKerr "Falling in love with someone who is not interested in you" this has happened in my dreams (nightmares) many times in the past. My point is that even if "I" am performing all the bitcoin computations in the world, as long as I cannot access that power that is not really me. If at some point I could that would be an "awakening" that would make a god out of me (in a pantheistic way), but so far that has not happened, I'm not a god, I'm not everything, thus there is something else. – Trylks – 2014-01-24T11:05:06.730

BTW: notice that with that definition of "I" you cannot answer a simple question like: "can I calculate as fast as a calculator?". The argument assumes that you can't, if you can't do that then there is something that can do it (the calculator). – Trylks – 2014-01-24T14:58:45.933

@Trylks - I already granted that it's a non-functional model (i.e. don't use it, it's stupid), even if it's a formal possibility that you're making it all up. Not really sure what your point is...? – Rex Kerr – 2014-01-24T15:52:08.393

@RexKerr The point very summarized is: there are things with different computational capabilities, therefore there are several things, therefore cogito ergo sum, I exist, but that makes one, I said several, therefore something else exists. We know these things that exist are real because the computations are real because the results match. – Trylks – 2014-01-27T18:56:34.710

@Trylks - I can (subconsciously) pretend that there are things with different computational capabilities, and then go along with the consequences. – Rex Kerr – 2014-01-27T19:31:38.273

@RexKerr still at least two things with different computational capabilities, subconscious and conscious. "Cogito ergo sum" applies twice, subconscious and conscious. – Trylks – 2014-01-28T12:15:42.783


There are weak and strong forms of Solipsism. Historically Solipsistic arguments have fallen along a spectrum between the two forms along a spectrum.

The most common form is the weak form, the original and simply asserts that the only axiom anyone can know for certain is that their own mind exist. That's Decartes. The rest of perceived existence may or may not exist, usually it is presumed to, but you will never know to the absolute degree you know of the existence of your own mind.

The strong form asserts that only one mind of one individual in the universe is real and everything else is just an invention of that mind.

The computational argument does not in anyway refute the weak form because the weak form is agnostic about the existence of something other than one's own mind. Instead, it makes a statement about the degree of certitude of which one knows any particular piece of information. In the weak form, the only absolutely certain piece of information is the existence of one's own mind but that in no way precludes the existence of other real things. You can just never be absolutely certain they exist to the absolute degree you can be certain your own mind exist.

So, seeing a computation carried out faster than your mind can do it tells you nothing because the weak form doesn't assert anything about whether anything exist outside your mind or not.

As to the strong form...hmmmm.

One of the core concepts of strong Solipsism down through the years has been that the one single real mind lives in a world of illusion that itself generates. The strong argument asserts that nothing outside the one mind exists, that includes all history, all beings, all inanimate objects and the computer.

The one true mind is constantly fooling itself that other things exist and that they have certain properties. One of the illusionary properties of computers is that they can out compute the human mind.

Since all the rest of us are virtual creations, the computational challenge will tell us nothing about our own existence because well we don't exist, the one true mind just imagines we do and imagines we think we do.

Even if the one true mind were to perform the computational experiment, it would appear that it would likely simply imagine that the computer outperformed the true mind just like imagines everything else e.g. optical illusions or surprises.

The computational experiment, as outlined, can never disprove Solipsism.

But, it could in one case prove Solipsism.

If the one true mind did perform the computational experiment, and outperformed the computer, then that would break the illusion. If one individual mind in the universe could always out compute any computing devices, despite the illusion of that being contrary to natural law, then the only explanation is that the computer is in fact a subset of the mind.

Or maybe not, this is philosophy after all.


Posted 2014-01-23T10:59:25.117

Reputation: 189


Yes it is an argument against solipsism, or at least the beginning of one. But it's not new.

Any indication that the world (dream world or real world or whatever) surprises you or seems to know more than you, supports this argument against solipsism. As the comments to your OP suggests, there's either a real external world, or a hidden part of you that's supplying the surprises, that's acting as your Wolfram Alpha.

So there's either an external world or a hidden part of you, separate from the you you're aware of. The solipsist view that the hidden part of you supplies the surprises, and supplies a consistent, useful and unfolding cause and effect framework (i.e. physics), really boils down to simply renaming the external world to "the hidden part of you". There's no useful distinction, but the solipsist view requires a more complicated/convoluted explanation than a realist's view, and that dooms it.

For a more thorough exploration:


Posted 2014-01-23T10:59:25.117

Reputation: 673

you say it's not new, but in fact you are misunderstanding it with an old argument. This is not about surprises, as you mention, this is about predictability. The result is predictable, the result actually matches, that's why we can know it's real, if it was unpredictable, once we see it, we wouldn't know whether it is real or not, whether it is right or wrong. – Trylks – 2014-01-27T18:57:59.887


You can improve your argument: Instead of letting a computer calculate a result, and then calculating the result yourself, take one of the many problems where it is very difficult for even the fastest computer to find a solution, but reasonably simple for a human to verify the result.

An example: It is very, very difficult to find three positive or negative integers a, b and c such that the sum of the cubes a^3 + b^3 + c^3 equals 30. A solution was found: a = 2,220,422,932; b = -2,218,888,517; c = -283,059,965. With pen and paper and a bit of concentration you can easily verify that these three numbers give a solution of the problem, but there is just no way that a human mind could find that solution.

Assuming solipsism, there are two explanations: One is that for some strange reason, your mind finds that the sum of these three cubes is 30 whenever you do the calculation, but in reality it isn't. The other explanation is that your brain has a either huge computational capacity or an incredible mathematical talent that is completely hidden from your conscious mind. Both explanations seem weak.


Posted 2014-01-23T10:59:25.117

Reputation: 3 297


To expand on obelia's answer, the issue with any form of strong solipsism is that it requires you have or create information subconsciously, which some unwritten law or your own subconscious mind purposely (for some unknown or unfathomed reason) hides from your conscious mind unless you "come by it honestly" through the senses that your mind gives you in the imaginary/constructed/simulated world that your subconscious has created.

Why would your subconscious limit your conscious mind from knowledge it has access to, unless you access it through your 5 senses as an objective reality?

That is the main objection I have to solipsism - it is a simple application of Occam's Razor, until such time as we learn more information.

For example, in the "Matrix" variant of the argument (or separate thought experiment, if you will), it's not really your subconscious that is limiting the information given to your conscious mind, but the "program" that you are plugged into. While the Matrix movies posit that we are trapped in a world that is very much like the "real world" that someone coming out of "the Matrix" would experience, this may not be the case at all - our subconscious could be hiding a completely different type of existence from us (or, indeed, even it may not know information about "ultimate reality").

Regardless, the point of solipsism is that we are really living in a bigger reality than our conscious mind has access to. Your solution doesn't dissolve the problem, it is only pointing out a different kind of limitation that solipsism imposes on our conscious mind from the knowledge that our subconscious mind must have, at least in part, of that greater reality.


Posted 2014-01-23T10:59:25.117

Reputation: 956


Solipsism cannot be proven false and the argument you proposed fails.

At step #8 you verify two pieces of paper contain the same numbers — but what prevents your mind from presenting you with two identical numbers? or with making you believe you are looking at two identical numbers?

In fact, this phenomenon happens regularly in your dreams.

You meet a nice woman in a bar, but she has the head of a goldfish and it does not bother you at all, and you fall in love with her.

or you read the paper and fail to notice that the letters are in continuous flux and the pictures are weird.

in dreams you can have fake memories, and the only indication you have for having started your philosophical experiment an hour ago, can be a fake memory.

Try lucid dreaming — you will have the fun of your life navigating the craziness your brain can produce for you every night.

Richard Feynman recounts a funny story of trying to make scientific observations and reasoning in his lucid dreams:

I'm dreaming one night as usual, making observations, and I see on the wall in front of me a pennant. I answer for the twenty-fifth time, "Yes, I'm dreaming in color," and then I realize that I've been sleeping with the back of my head against a brass rod. I put my hand behind my head and I feel that the back of my head is soft. I think, "Aha! That's why I've been able to make all these observations in my dreams: the brass rod has disturbed my visual cortex. All I have to do is sleep with a brass rod under my head, and I can make these observations any time I want. … When I woke up later, there was no brass rod, nor was the back of my head soft.


Posted 2014-01-23T10:59:25.117

Reputation: 4 231