Consciousness

[jonb]

I've sometimes wondered where that line is between sentience and stimulus response in some beings? At what point is life so simple as to not be aware of its own existence?

Viruses, technically not even meeting the definition of life in biology, operate enough to seek out cells, infect them and produce copies of themselves. Micro-organisms operate according to stimulus response but are unlikely to be sentient as they have no brains as we know it. Plant life and fungus life also lacks a central nervous system and a brain. What about insects? Are they aware of their own existence? Cats and dogs seem to be able to interact with others and bond socially, which could be an indication they are self-aware. So where's the line drawn?

For me, I would set the pole very low. If a thing has a choice, and consistently makes choices which seem to be in its own interests, I would say there is some self-awareness there.