New edgy thread

Ah I see ! yes, everything is up for grabs epistemologically, everything is questionable, always, agreed.

But "I think therefore I am" (or whatever Mr D said) comes to mind - - - agree ?

Yes, another attempt at a solution to the same epistemological conundrum, Descartes thought there was a material world as well as a mental world; Berkeley thought there was only mental stuff, our ideas and ideas in the mind of God.

Not sure I agree, I could take that question, blank out the word 'sound' (or related words) and ask you to fill in the blanks, and the question would become axiomatic.

I could be wrong of course but I have never seen it as anything other than equivocation, I am sure you can attach interesting (and worthy/good/true) ideas onto the conceit - but the central question is a scientific question.

When the tree falls - is sound produced if no one there to hear it.

Define sound:

Sound is the air vibrating - then yes the air will vibrate whether someone is there or not, in that respect sound is produced.

Sound is your ear drums vibrating - then if you are not there and your ear drums do not vibrate then no sound is produced.

I would replace your second definition with:

Sound is the sensation experienced by a (healthy, normal) subject when its ear drums vibrate (say).

So a scientist would be inclined to say: there is no sound in the second sense if the tree falls and there is no one around with ear drums to rattle and have sensations, but that seems just trivially built in to this definition of sound. The idea of a sensation of sound has no explanatory force.

And if you start from the position that there is a knowable, objective, physical world that has physical 'subjects' (us) living in it, that is a sensible view.

But Berkeley was starting from the position that the only things each of us really knows first hand are our sense perceptions, our ideas; and everything we might think we know about a material world is ultimately derived from them. We have no first-hand knowledge of the material world, and if we're strict with ourselves, we should, as he does, deny that it exists at all. So the second definition of sound takes massive precedence over the first in his way of thinking, precisely because it starts out from what he thinks each of knows for sure exists - our own sense data.

The problem is, if there are only ideas, as he thinks, how can it be that some idea-things, such as places, people, trees, can disappear from view or earshot then re-appear as if they had continued to exist in some sense in the mean time, outside my mind, possibly outside of everyone's mind? How can that tree falling in the forest make a noise if no one is around to hear it? That's where God comes in.

You really have to entertain this view of the world in all its nutty glory to get past the idea that the falling tree question is just a matter of definition - and I'm not saying that you should!