Posted by alexandra_k on May 5, 2005, at 22:17:27
In reply to How do we know anything?, posted by alexandra_k on May 5, 2005, at 22:02:36
Would things seem any different to you if in fact all these things existed *only* in your mind - if everything you took to be the real world outside was just a giant dream or hallucination, from which you will never wake up? If it were like that, then of course you *couldn't* wake up, as you can from a dream, because it would mean there was no "real" world to wake up into. So it wouldn't be exactly like a normal dream or hallucination. As we usually think of dreams, they go on in the minds of people who are actually lying in a real bed in a real house, even if in the dream they are running away from a homicidal lawnmower through the streets of Kansas City. We also assume that normal dreams depend on what is happening in the dreamer's brain while he sleeps.
But couldn't all your experiences be like a giant dream with *no* external world outside it? How can you know that isn't what's going on? If all your experience were a dream with *nothing* outside, then any evidence you tried to use to prove to yourself that there was an outside world would just be part of the dream. If you knocked on the table or pinched yourself, you would hear the knock and feel the pinch, but that would be just one more thing going on inside your mind like everything else. It's no use: If you want to find out whether what's inside your mind is any guide to what's outside your mind, you can't depend on how things *seem* - from inside your mind - to give you the answer.
But what else is there to depend on? All your evidence about anything has to come through your mind - whether in the form of perception, the testimony of books and other people, or memory - and it is entirely consistent with everything you're aware of that *nothing at all* exists except the inside of your mnd.
It's even possible that you don't have a body or a brain - since your beliefs about that come only through the evidence of your senses. You've never seen your brain - you just assume that everybody has one - but even if you had seen it, or thought you had, that would have been just another visual experience. Maybe *you*, the subject of experience, are the only thing that exists, and there is no physical world at all - no stars, no earth, no human bodies. Maybe there isn't even any space.
The most radical conclusion to draw from this would be that your mind *is* the only thing that exists. This view is called solipsism. It is a very lonely view, and not too many people have held it. As you can tell from that remark, I don't believe it myself. If I were a silipsist I probably wouldn't be writing this book, since I wouldn't believe there was anyone else to read it. On the other hand, perhaps I would write it to make my inner life more interesting, by including the impression of the appearance of the book in print, of other people reading it and telling me their reactions, and so forth. I might even get the impression of royalties, if I'm lucky.
Perhaps you are a solipsist: in that case you will regard this book as a product of your own mind, coming into existence in your experience as you read it. Obviously nothing I can say can prove to you that I really exist, or that the book as a physical object exists.
On the other hand, to conclude that you are the only thing that exists is more than the evidence warrants. You can't *know* on the basis of what's in your mind that there's no world outside it. Perhaps the right conclusion is the more modest on ethat you don't know anything beyond your impressions and experiences. There may or may not be an external world, and if there is it may or may not be completely different from how it seems to you - there's no way for you to tell. This view is called skepticism about the external world.
poster:alexandra_k
thread:494272
URL: http://www.dr-bob.org/babble/social/20050503/msgs/494275.html