Post-humanism is one of the favourite themes of speculative fiction, and the world is not short of futurists like Cory Doctorow who believe it could one day be fact. The basic idea is that through technology humans will one day transform ourselves into something different to what we are now.
Greg Bear (among many others) imagines that humans will be able to upload their consciousness into a huge database in which they will potentially live forever, divorced from any physical existence but preserving their individual consciousness in the company of other disembodied "elders".
Doctorow imagines that our memories and thoughts might be recorded at a remote back-up location, to be refreshed and revived in the event of a catastrophic local breakdown.
Iain M Banks describes a society where medical technology enables people to become whatever they want. They can change gender, physical appearance, even species with the essence of their personalities preserved through a potentially infinite number of such changes. People can potentially live forever, although most choose not to. Those who do most often live on only as disembodied memory pods, waiting to be revived at some unspecified future when something comes along that might be interesting enough to rekindle their interest in life.
There's something seductive about these futures. They promise us eternity, relief from our physical suffering, relief from the dangers of accident and illness, relief from the ravages of dementia. Yet the term "post-humanism" is a good one, because you have to wonder to what extent the beings created in this kind of world would be human. So much of who we are is conditioned by our physicality. We see, hear, smell and feel through physical membranes and nerve endings. Without these, how would we perceive the world? How would our relationships with one another, our empathy and solidarity, survive? Would we suffer from sensory deprivation and go mad? Would we become the detached, pure spiritual beings envisaged by Buddhist or Christian mysticism?
I was reminded of this by an article in The Australian by Greg Sheridan, a lifelong Catholic. He says
...there's one aspect of orthodox Christian belief I have found strange and mysterious in ways that almost make me uncomfortable, and that is the doctrine of the bodily resurrection...that not only did Christ rise from the dead in bodily form, that is to say his physical body, in a transformed state, rose from the dead...(but) that all human beings will rise from the dead in their transformed bodies.
There are two difficulties I have with this doctrine. One is that growth and decay seem of the very essence of humanity.... The other is that it is just impossible to imagine the body renewed and lasting forever. And a third, how is there purpose in changelessness?
He goes on to say that this is not a faith killer for him. It's just one of the infinite number of things he doesn't understand.
It seems Sheridan and the post-humanists are struggling with the same issue. The post-humanists, in their various ways, are struggling with our intuition that we are eternal beings, that there is more to our existence than the physically finite eighty years (give or take) of human life. Their technological triumphalism leads them to replace God with ourselves, or perhaps with an artificial intelligence which grows out of what we create.
This surrogate god confers on us the gift of eternity, but this gift is not necessarily an unalloyed good. It is something we have to wrestle with, because it changes us irreparably. It's possible that our nature will change completely. It's possible we won't be able to stand eternity in the end and will choose to bring our lives to an end. On the other hand its possible that in our new bodies, fleshly or electronic, we will find possibilities we can't so much as imagine from our present prisons of flesh and bone, and that these possibilities will be enough to fill several eternities.