Onifre, way back in this thread, notes:
I would hesitate to simply refer to it as "awareness" of ones self and ones enviroment. In my opinion, there are deeper levels of consciousness that require no environment (REM sleep, hallucinations, etc.) that are specific, assumingly, to humans.
Now I know Oni has seen sleeping dogs dreaming and cats suddenly stare at nothing....but I'm thinking here that Dreaming may be the best evidence of consciousness in the species at hand. Does an amoeba dream? An ant? A turtle? What animals sleep? Why is there sleep? There was another thread in this forum somewhere that i fergitz. What is the evolutionary advantage to sleeping? I think....
I read somewhere that dreaming is what happens when your brain, needing to compress the daily intake of new data into the storage system, may find itself opening "boxes" of other stuff in there and rearranging the packing of the storage space to accommodate the new stuff for later use. Sometimes the packing activity is too loud and seeps up into your consciousness as a dream.
However, while I would say that all conscious beings dream, it does not imply that in order to have consciousness you have to be able dream. It's a nice romantic thought and all, but it doesn't follow.
- xongsmith, 5.7d