The simple answer is that we don't know yet. We don't know at what level of complexity a nervous system starts to have subjective experience (qualia), or even how to detect the condition. However, constructing a computer program that's aware of its own programmedness, or a robot that can tell itself apart in (for example) a reflection from other robots is not terribly difficult. Do such machines have qualia? How could we know? How can I know
you have qualia?
What we do know is that doing purely physical things to the brain has very apparent effects on the person. People with brain damage have suffered effects as varied as changes in personality, to defects in information processing, to loss of abilities and memories. Less extremely, psychoactive drugs operate physically on the brain and cause changes in behavior, mood, and perception.
If the brain is not the seat of consciousness and the self is instead the result of some metaphysical process that's external to the body, these effects remain to be accounted for. And that aside, I've never heard any reason to accept dualism, besides an appeal to incredulity that the mind could be caused purely by physical processes.
What we do know is that doing purely physical things to the brain has very apparent effects on the person. People with brain damage have suffered effects as varied as changes in personality, to defects in information processing, to loss of abilities and memories. Less extremely, psychoactive drugs operate physically on the brain and cause changes in behavior, mood, and perception.
If the brain is not the seat of consciousness and the self is instead the result of some metaphysical process that's external to the body, these effects remain to be accounted for. And that aside, I've never heard any reason to accept dualism, besides an appeal to incredulity that the mind could be caused purely by physical processes.