Here I would posit, that ideas are inherently not physical. The physical can only ever be representative of ideas. This applies on every level, and ultimately even to the brain.
One will say that ideas are just information, but no physical system can have access to the information that it represents, because it just kicks the can down the road. What does "access" here mean? Access is the ability to evaluate and manipulate.
An example. The idea of a chess queen. This can be represented by literally any physical thing. Like wise, the piece can be moved around the board by any kind of physical force. Yet, access to the idea of a chess queen, is not accessible to any of those physical things themselves.
This is because there exists a wall between ideas and physical manipulation. This is evidenced by the "Chinese room" thought experiment. What this experiment shows is that the moving of symbols by physical force or rules (whatever they may be) does not gain access to the IDEAS that the symbols represent. As all physical interactions fall into this category, thus purely physical things can have no access to ideas.
Objection #1
One may say, but we access ideas. Indeed we do, but because of the above "wall" of separation between ideas and purely physical things, we should reject a purely physical explanation, unless some solution is shown to be plausible with explanatory power.
Related thread, where I think I presented too much at one time.
http://www.onlinedebate.net/forums/s...-rule-them-all
Bookmarks