Our subjective experience of the continuity of consciousness is
surely an illusion. But what makes that illusion and why is it so
compelling? That's a deep question but here are I think two fundamental
reasons:
- Embodiment.
You are an embodied intelligence. It is a mistake to think of mind and
body as somehow separate. Our conscious experience and its awakening as
a developing child is surely deeply rooted in our physical experience
of the world as mediated through our senses.
- Environmental continuity.
Our experience of the world changes 'relatively' slowly. The word
relative is important here since I mean relative to the rate at which
our conscious experience updates itself. Of course we do experience the
discontinuity of going to sleep then waking to the changed world of a
new sunrise, but this is both deeply familiar and predictable.
A word that encompasses both of these is situatedness.
Our intelligence, and hence also conscious experience is inextricably
situated in our bodies and in the world. Let me illustrate what this
might mean with a thought experiment.
Imagine a brain
transplant. Your brain complete with its memories and life's
experience, together with as much of your central nervous system as
might be needed for it to function properly were to be transplanted
into a different body. You would wake from the procedure into this new
body. I strongly suspect that you would experience a profound and
traumatic discontinuity of consciousness and, well, go mad. Indeed it's
entirely possible that you simply couldn't (and perhaps mercifully)
regain or experience any sort of consciousness at all. Why? Because the
conditions for the emergence of consciousness and the illusion of its
continuity have been irreversibly broken.
However, if what I have said above is true, there's a flip side to the story that could have extraordinary consequences.
If
the continuity of consciousness is an illusion then, in principle at
least, it might be possible to artificially perpetuate that illusion.
Imagine
that at some future time we have a sufficiently deep understanding of
the human brain that we can scan its internal structures for memories,
acquired skills, and all of those (at present dimly understood)
attributes that make you you. It's surely safe to assume that if we're
able to decode a brain in this way, then we would also be able to scan
the body structures (dynamics, musculature and deep wiring of the
nervous system). It would then be a simple matter to scan, at or just
before the point of death, and transfer those structures into a virtual
avatar within a virtual world. The simulated brain structures would be
'wired' to the avatar's virtual body in exactly the same way as the
real brain was wired to its real body, thus satisfying the requirement
for embodiment. If the virtual world is also a high fidelity replica of
the real world then we would also satisfy the second requirement,
environmental continuity.
I would argue that, under these
circumstances, the illusion of the continuity of consciousness could be
maintained. Thus, on dying you would awake (in e-heaven), almost as if
nothing had happened. Except, of course, that you could be greeted by
the avatars of your dead relatives. Even better, because e-heaven is
just a virtual environment in the real-world, then you could just as
easily be visited by your living friends and relatives. Could this be
the retirement home of the far future?
In this way human consciousness could, I believe, be immortal.