tlb wrote:The concept of sentience is not as easy as you seem to imply. In particular, your statement that "dolphins and chimpanzees aren't sentient" is highly suspect. You seem to be defining sentience by how well they interact with humans. At the bottom I include the conclusion of an online paper that I found by Professor Juan Carlos Marvizon, copyright 2019.
Oh, no doubt it's a thorny subject. Clearly we don't have a good definition of what sentience is. In the Cosmos series, Neil de Grasse Tyson was also describing how many animals have behaviours that we "common sense" would say are exclusive to humans, like lying, tool-using, planning for the future, sense of society, etc. Your excerpt is an example of that discussion.
But in-universe, we have a sentience scale, which managed to score treecats quantitatively above dolphins (and that was before they revealed they could really communicate). That means there's a reasonably accepted formula. And if there's a formula, you can apply a threshold to say "these are non-sentient, these are semi-sentient and these are sentient."
Also I am not sure that uplifting simply means adding sentience; for example if humans could be modified to be empaths (like Honor) or even more to be telepaths, then that would seem to be uplifting.
That would go back to the definition of sentience. If tele-empathy isn't required for sentience, genetic modification to add it shouldn't be allowed. And yet eugenic selection could achieve it.
David Brin didn't address this as no species in the Civilisation of the Five (Four) Galaxies seem to have telepathy.