I've always had a bit of a problem with materialism. The problem is that I'm not quite sure what it means.
"Read a bloody dictionary", you suggest helpfully. OK:
Materialism: a theory that physical matter is the only or fundamental reality and that all being and processes and phenomena can be explained as manifestations or results of matter.
Now, at first glance, this seems reasonable enough, and indeed true. But if you look at it more closely, you start to wonder if it is a theory. What would falsify it? What sort of thing could we find that we would declare not to be matter?
'Cos, after all, what do scientists do when they find something that isn't a solid or a liquid or a gas or a plasma or a liquid crystal or a Bose-Einstein condensate or ... etc, etc. Why, they say "We have discovered a new form of matter which is neither a solid nor a liquid nor a gas nor a plasma nor a liquid crystal nor a Bose-Einstein condensate nor ... etc, etc". They do not, ever, say "We have found something that isn't matter, thus falsifying materialism".
So can we identify a point at which this must stop? Can we think of anything that can't be called matter, or having a substrate which can't be called matter? If not, is materialism actually a theory, or just an agreement about how to use words?