What the heck is consciousness anyway?

[iancampbell]

Bear - That depends on your definition of sentience. Right at the bottom, something like a central heating thermostat could be said to have 1-bit sentience - in that it senses one variable and acts whenever that variable changes. Slightly less ridiculous, one could think about something like an earthworm; it acts to move away from harmful stimuli (heat, saltiness, too much light perhaps) and moves towards beneficial ones such as the smell of food. I very much doubt, however, that most people would take this to mean earthworms have emotions.

Incidentally, this does not mean that everything is sentient. A lump of granite reacts to being wet by (VERY slowly) changing its chemical composition - but it's not doing so actively.