Some contemporary non-religious dualists argue that the mind is not fully physical – that it functions beside, or emerges from, the physical brain.
The physicalist gives two replies:
- Every mystery ever solved has turned out to be non-dualist. Why think mind will turn out to be any different once we understand it?
- Drugs or damage change our states of consciousness, brain scans can read our thoughts, etc. Every investigation of the mind so far has supported the above point; that minds are physical.
The dualist replies, “But our view that some of the mind not physical is fully consistent with the data so far!”
The physicalist rejoins:
Logical consistency with the facts is not impressive. Here, I’ll make up a theory of consciousness right now that is consistent with the fact. Let’s call it the Gremlin Theory of Consciousness: Consciousness arises from the telepathic communication of trillions of undetectably small gremlins associated with each mind. That’s consistent with the facts. The problem with the dualistic theory of mind and the gremlin theory of consciousness is that there’s no evidence in their favor. Please, point at some evidence for your position.
So, does the dualist point to some of the latest evidence from cognitive science? Or with a new revelation in quantum physics?
Not in the cases I’m considering. When pointing at evidence for dualism, many dualists turn their pointer finger back on themselves and say, “My own subjective intuitions about the metaphysical possibility of zombies is my evidence.”
Lest you think I’m attacking a straw man; I’m totally not.
The physicalist’s first reaction may be what David Lewis said was the most common reaction to his defense of the idea that all possible worlds actually exist: an incredulous stare.
Once he recovers from shock, the physicalist might reply:
Your evidence is… your intuitions about the metaphysical possibility of zombies? Are you frigging kidding me? Let me know when you have some real evidence.
This is the problem with philosophers. A scientist would never publish a paper citing as evidence his intuitions that his new theory is correct. The entire scientific community would reject that as a waste of time.
Have you not kept up with the last 50 years of cognitive science? Don’t you know your brain is a godawful kludge of messily evolved parts? We can’t introspect our way to reliable knowledge of the moment we decided to act or even the phenomenological quality of our own conscious experience – why on earth would you think you have introspective access to truths about the metaphysical possibility or impossibility of zombies? Why think that your brain evolved to have reliable intuitions about such esoteric things?
I keep thinking that intuitionism has been killed off by contemporary cognitive science and experimental psychology, but I keep finding that I am wrong.