Imagine that you are the only being that exists. Not that you are the last person on earth, but that the earth and everything other than you is merely the product of your deranged imagination. This, very crudely put, is solipsism.
As with watching Star Trek, most philosophers go through a solipsism phase. As with the Macarena and Gangnam Style, this phases usually fades with merciful rapidity. This fading is, however, usually not due to a definitive refutation of solipsism. In many cases, philosophers just get bored with it and move on. In other cases, it is very much like the fads of childhood-it is okay to accept the fad as a kid, but once you grow up you need to move on to adult things. Likewise for solipsism-a philosopher who plays with it too long will be shamed by her fellows. Mostly.
Just for fun, I thought I would play a bit with solipsism-in the manner of an adult who finds an favorite childhood toy in the attic and spends a few moments playing with it before setting it aside, presumably to go write a status update about it on Facebook.
Interestingly enough, solipsism actually has a lot going for it-at least in terms of solving philosophical problems and meeting various conditions of philosophical goodness.
One obvious thing in favor of solipsism is that, as per Descartes’ wax example, every experience seems to serve to prove that I exist rather than that something else exists. For example, if I seem to be playing around with some wax, I can (as per Descartes) doubt that the wax exists. However, my experience seems to show rather clearly that I exist and doubting my existence would just serve to prove I exist. In fact, as skeptics have argued for centuries, it seems impossible to prove that there is anything external to myself-be it an external world or other minds. As such, solipsism seems to be the safest bet: I know I exist, but I have no knowledge about anything else.
Another factor in favor of solipsism is its economy and simplicity. All the theory requires is that I, whatever I am, exist. As such, there would presumably be just one ontological kind (me). Any other theory (other than the theory that there is nothing) would need more stuff and would need more complexity. These seem to be significant advantages for solipsism.
A third factor is that solipsism seems to solve many philosophical problems. The problem of the external world? Solved: no such thing. The problem of other minds? Solved: no such things. The mind-body problem? Probably solved. And so on for many other problems.
Naturally, there are various objections to solipsism.
One obvious objection, which I stole from Descartes (or myself), is that if I was the only being in existence, then I would surely have made myself better. However, I make no claims to being omnipotent-so perhaps I made myself as well as I could. Or perhaps I did not create myself at all-maybe I just appeared ex-nihilo. In any case, this does not seem to be a fatal problem.
A related objection is the argument from bad experiences: cannot be the only thing in existence because of the bad experiences I have. I’ve experience illness, injury, pain and so on. Surely, the argument goes, if I was the only being in existence I would not have these bad experiences. All my experiences would be good.
Laying aside the possibility that I am a masochist, the easy and obvious reply is to point out that a person’s dreams are produced by the person, yet dreams can be nightmares. I’ve written up many of my nightmares as horror adventures for games such as Dark Conspiracy and Call of Cthulhu so it can be gathered that I do have some rather awful nightmares. I also have dreams with more mundane woes and suffering, such as nightmares about illnesses, injuries and so on. Given that it is accepted that a person can generate awful dreams, it would seem to make sense that the same sort of thing could happen in the case of solipsism. That is, if I can dream nightmares I can also “live” them.
Another objection is that the alleged real world contains things that I do not understand (like specialized mathematics) and things I could not create (like works of art). As such, I cannot be the only being that exists.
The easy and obvious reply to the understanding reply is that I understand as much as I do and the extent of my understanding defines what seems possible to me. To be a bit clearer, I have no understanding of the specialized mathematics that lies beyond my understanding and hence I do not really know if there is anything there I do not actually know. That is, what is allegedly beyond my understanding might not exist at all. Interestingly, any attempt to show that something exists beyond my understanding (and hence must be created by someone else) would fail. To the degree I understand it, I can attribute it to my own creation. To the degree I do not, I can attribute it to my own ignorance.
In terms of the art objection, the easy reply is to note that I can dream of art that I apparently cannot create myself. To use an example, in the waking world, I have little skill when it comes to painting. But I have had dreams in which I saw magnificent original paintings I had not seen in real life. The same applies to dream statues, architecture and so on. As such, the art that seems beyond me in the world could be produced in the same way it occurs in dreams.
Descartes (or me), I think, had the most promising project for refuting solipsism: if I can find something that I cannot possible be the cause of, then that gives me a good reason to believe that I am not the only being in existence. Or, more accurately, that I am not the only being to ever exist. However, there does not seem to be anything like that-after all, everything I experience falls within the limits of me and hence could all be about and only me.
But surely that is crazy.