Replace one neuron in your brain by a functionally equivalent chip. Would you still be conscious? Of course. Alcohol damages us more, and we remain conscious beings. But if you replace two, two billion, all the neurons? If you simulate them on a computer? What if you simulate them on paper, with a human emulating the computer? After all, hardware makes no difference. I've just discovered one of my favourite essays online, A Conversation with Einstein's Brain from Douglas Hofstadter and Daniel Dennett's book The Mind's Eye. And it's about this very question. Read it, and see whether you enjoy it as much as I did.