> > When 99% of the human race use the word "reality", they mean
> > the world outside their skins.
> > If you sacrifice our common understanding of "reality", then
> > you'll find yourself in a hole out of which you'll never climb.
> Yes, but what *is* this 3D world we can all stub our toe on?
Korzybski would warn: beware the "is" of identity :-)
> If we go back to the start of last century, Rutherford's
> quaintly pre-QM atom, amazingly, turned out to be mostly
> empty space. Did this mean that, suddenly, it doesn't hurt
> when you walk into a brick wall, because it isn't nearly as
> solid as you initially thought it was? Of course not; our
> experience of the world is one thing, and the "reality"
> behind the experience is a completely different thing.
That's *exactly* right. We *could* have been designed by
evolution not to hurt when we walked into a wall. For certain
reasons, we were not designed that way.
> If it is discovered tomorrow beyond any doubt that the
> entire universe is just a game running in the down time
> on God's pocket calculator, how is this fundamentally
> different to discovering that, contrary to appearances,
> atoms are mostly empty space, or subatomic particles have
> no definite position, or any other weird theory of modern
Good analogy! The world surprises us all the time, especially
the more we learn about it. It would be bizarre if it did not,
(we'd probably have to abandon most of our theories).
> And how could, say, the fact that brick walls feel solid enough
> possibly count as evidence against such an anti-realist theory?
Occam's razor. We go with the simplest theory. Imagine
that you and I believe we are standing next to a wall.
Our conjecture is that it has certain properties. We
may need it to protect us. If we're wrong, nature will
make short work of us. That we have survived this long
is a strong indication that the wall really is there.
In fact, on some level of practicality, it is foolish
to debate the existence of the wall. Samuel Johnson
did refute Berkeley.