on matter and space:
let us move beyond dualism, that that exists is either mental or physical, and idealism, that all that exists is mental, and physicalism, that all that exists is physical. these arguments, after all, only involve two concepts, the mental and the physical. may i suggest that reality is more complex than that. perhaps there are things that truly exist that could not be categorized by either term!
the external world as it seems, i have argued, does not exist, but i do not deny the possibility that physical objects may exist independently "out there". for all i know, there may be a permanent tree that is lodged, forever fixed in space at certain coordinates, and there may be a statue of a human body out there too!
even mental components vary, to hear, to see, and so on, so as to render the term as perhaps too wide. but are there "in between" senses, perhaps where light merges with thought, and with mood, for example? surely there is not just one base mental component that can change to very different states, for example, what becomes light cannot become sound, surely?
and can you hear and see things at the same point in space in front of you? it seems you can in a general area and so the question becomes more complex. allow me to digress, let us call all things that exist, matter. if we consider all the definitions of the word and all its usages, this seems to be where a common meaning is found. are there only 3 dimensions to real space? so it seems. theoretically if there were more, say 4 or 5, a sound and the light could appear to be at the same point in virtual 3D space. or, there are only truly 3 dimensions in real space and it just happens that sound matter and light matter are closely packed together in a mixture, and it just seems that light and sound happen at more or less the same point.
if there is more than that that is physical or mental, what is it? it seems that to make a virtual world work, it requires electronics. the universe may be a vast, virtual work in progress, powered by a supercomputer, with electronics forming connexions that translate everything to the senses.