Identity

our identity is pretty much an illusion. it's a program running on our brain for a bunch of reasons, one of which is probably to help preserve our bodies. the feeling that we cannot be replaced is to help convince us to stay alive. it wouldn't matter if somebody replaced a human with a copy in his or her sleep, it may have already happened to me, no different would be detected. our mind is the result of information encoded into a bunch of atoms. although the mind itself is a rather weird thing - it's not the atoms really - just something riding on top of physics. i don't know if humans will carry the concept of identity into the distant future when they are computing things on machines other than brains.