I was thinking of something simpler: the flexibility of meaning of the word 'consciousness' -- for example, in Merriam-Webster:
1a: the quality or state of being aware especially of something within oneself. (my emphasis.)
If you regard 'especially' to indicate that the emphasized clause is optional (edit: or maybe even if not), you could arguably say (and people do) that anything alive fits this definition, as do even things like thermostats. This, however, is not the consciousness that the science and philosophy of mind is concerned with: it is specifically concerned with the sort of consciousness that we exhibit, which is aware that it is an agent in the world, aware that it has this awareness, and aware that other people are also aware in this sense.
Update: I may have misunderstood your question. The nature of consciousness in other animals is also an open issue and is being studied. It would be very odd indeed if there was nothing like it in any other species, but, at the same time, no other living species on earth has it to the extent we do. I don't think these observations justify the extremely broad definitions of panpsychism, and I do not think panpsychism helps with studying these animals any more that it helps with humans.
Nagel's point is, I think, rather tangential - he is arguing that we probably will never know what it is like to be a bat, as it is likely too far from any experience we could have. I think he is probably right, and again, panpsychism will not change that.
1a: the quality or state of being aware especially of something within oneself. (my emphasis.)
If you regard 'especially' to indicate that the emphasized clause is optional (edit: or maybe even if not), you could arguably say (and people do) that anything alive fits this definition, as do even things like thermostats. This, however, is not the consciousness that the science and philosophy of mind is concerned with: it is specifically concerned with the sort of consciousness that we exhibit, which is aware that it is an agent in the world, aware that it has this awareness, and aware that other people are also aware in this sense.
Update: I may have misunderstood your question. The nature of consciousness in other animals is also an open issue and is being studied. It would be very odd indeed if there was nothing like it in any other species, but, at the same time, no other living species on earth has it to the extent we do. I don't think these observations justify the extremely broad definitions of panpsychism, and I do not think panpsychism helps with studying these animals any more that it helps with humans.
Nagel's point is, I think, rather tangential - he is arguing that we probably will never know what it is like to be a bat, as it is likely too far from any experience we could have. I think he is probably right, and again, panpsychism will not change that.