zlacker

I feel like the barrier between conscious and unconscious thinking is pretty fuzzy, but that could be down to the individual.

I also think the difference between primitive brains and conscious, reasoning, high level brains could be more quantitative than qualitative. I certainly believe that all mammals (and more) have some sort of an internal conscious experience. And experiments have shown that all sorts of animals are capable of solving simple logical problems.

Also, related article from a couple of days ago: Intelligence Evolved at Least Twice in Vertebrate Animals

>>throwu+(OP)
Great points, but my apologies I meant to say "sentience". Certainly many, many animals are already conscious.

I'm not sure about the quantitative thing seeing as there are creatures with brains much physically much larger than ours, or brains with more neurons than we have. We currently have the most known synapses though that also seems to be because we haven't estimated that for so many species.