Amy Kindresulting uploaded entity be me? Given that we are conscious beings, an affirmative answer to
the second question depends on an affirmative answer to the first question – and this will be
true whatever theory of personal identity one adopts. But as it would here take us too far afield
to do the requisite survey of theories of consciousness needed to answer the first question, we
will here focus solely on the second question.^10 Do we have grounds to believe that any of these
methods of uploading would successfully preserve personal identity?
In Chalmers’s view, there are good grounds for pessimism with respect to both destructive
and nondestructive uploading. Consider first nondestructive uploading, and call the system that
results from a nanotransfer DigiDave. In such a case, since the original Dave still exists, Dave
and DigiDave cannot be numerically identical to one another. But if Dave does not survive as
DigiDave in the case where the original system is preserved, we might wonder why Dave would
survive as DigiDave in the case where the original system is destroyed.
Here we see a similar dialectic as in the case of teleportation, and similar moves could be
redeployed to make a case for the preservation of personal identity in the destructive upload-
ing case. But rather than rehearse those moves, let’s instead turn to gradual uploading – the
uploading scenario about which Chalmers suggests we have the most reason to be optimistic.
The case for optimism rests on a simple argument. It seems pretty plausible that when just one
percent of someone’s brain is replaced by functionally isomorphic robotic technology, personal
identity is preserved. To deny this would seem to commit one to the result that the destruction
of even a single neuron of someone’s brain would lead to their death. But now suppose that,
having replaced one percent of someone’s brain, we slowly repeat the process once a month, so
that by the end of 100 months the original system is completely destroyed and we are left with
a system that has been wholly uploaded to nanotechnology. It seems plausible that the original
person still exists after month two, and after month three, and so on. So where would we draw
the line? Letting Daven stand for the system after n months, we get the following argument (see
Chalmers 2014: 111):
1 For all n < 100, Daven+1 is identical to Daven.
2 If for all n < 100, Daven+1 is identical to Daven, then Dave 100 is identical to Dave.
3 Therefore, Dave 100 is identical to Dave.
Chalmers himself finds this argument reasonably convincing, though not everyone agrees (see,
e.g., Pigliucci 2014: 126-128; Corrabi and Schneider 2014: 138–140). Ultimately, then, it may
be that we’ve reached something of a stalemate. At the end of the previous section, I noted that
the conceptual possibility of uploading would count against the physical approach to personal
identity and in favor of the continuity of consciousness approach. Insofar as our intuitions about
the possibility of uploading are inextricably intertwined with our intuitions about personal
identity, we might not be able to use the former to help us sort out the latter.
That said, if there were other reasons to believe in the possibility of immortality – reasons
arising from considerations other than the kinds of uploading scenarios we’ve just discussed –
such reasons could indeed be relevant to the personal identity debate. In fact, we wouldn’t even
need full-on immortality for such reasons to be effective. Evidence that one could exist without
one’s physical body, even if only for a brief stretch and not for an immortal afterlife, would still
count against the physical approach.
Some philosophers point to Near Death Experiences (NDEs) as a possible source of such
evidence. While NDEs are often described as having an ineffable quality, in typical cases the
individual experiences emotional detachment – and, in particular, an absence of fear – and has
the impression of having left his or her body. As described by David Lund (2009), NDEs often