The utter primacy of H. sapiens in all the theistic religions is one of the things that bothers me most deeply about them. I believe we are unique and unusually important amongst life on earth (as were the first oxygenic photosynthesizers, and the first eukaryotic organisms, and the first macroscopic multicellular life forms), but I don’t think that the earth without humans would be without value. Diminished, certainly, but still a precious place. By the same token, I think that we diminish the value of the earth by causing the extinction of other species.
I think this may actually be somewhat related to the abortion question, and the difficulty of coming to any kind of common ground on it. I don’t consider non-viable fetuses human, but to me that doesn’t mean they are without value, or undeserving of any kind of legal protections. I just don’t think those protections should be as extensive as our protections of humans. People are resistant to the idea that “humanity” is a continuum. Some might even say repelled by it, but it seems inescapable to me. I also believe that severely mentally disabled people are “less” human, and that a brain-dead human is, for all intents and purposes, a cell culture with no more moral value than a side of beef. This might seem like something we had better not talk about, since it starts off all kinds of slippery slopes to horrible places, but I think eventually, we will have no choice, because some time in the next few decades, or at most the next few centuries, we will be confronted with positive deviations as well as negative.
What will it mean to be human, when there exist super-humans? When some portion of the population is genetically or cybernetically enhanced, will they have super-human rights, privledges, and responsibilities, or will they simply be more powerful through extra-legal means?
A person, even a politician, can stand up for human rights while condoning abortion if they do not consider the fetus human. The core of the abortion argument is what does it mean to be human? Is it a discrete, or continuous classification? Unless we can come to some consensus on these questions, the abortion issue, and many others, will remain vexing indefinitely.