Sanghamitta wrote:The thing is, you could build a robotic ant which responds to stimuli in exactly the same way as a biological ant so that a casual observer would not know the difference.
How do we know that our fellow humans are not in fact zombies responding to external stimuli in a way which makes us only believe they're sentient, when in fact they may very well not be? Isn't the idea that anything aside from us is sentient or conscious simply an act of faith?
There is no satisfying answer to what is truly conscious or sentient, because we don't know what role consciousness plays. What does the property of being conscious do? Is a thermometer conscious? Do different beings have different 'magnitudes' of consciousness?
The only thing we are certain of is that we are conscious; that we experience, think and percieve. Any speculation as to what other than yourself is conscious is based on one's own belief and intuitions.