Three possibilities come to mind:
Is there an evolutionary purpose?
Does it arise as a consequence of our mental activities, a sort of side effect of our thinking?
Is it given a priori (something we have to think in order to think at all)?
EDIT: Thanks for all the responses! Just one thing I saw come up a few times I’d like to address: a lot of people are asking ‘Why assume this?’ The answer is: it’s purely rhetorical! That said, I’m happy with a well thought-out ‘I dispute the premiss’ answer.
That’s a fascinating concept.
And yes - though a yank, I know Doctor Who. ;)
(And this is the point at which I accidentally tapped “Reply” last time through, which is why there’s a deleted post before this one)
Anyway…
My first reaction was that it didn’t make sense that a consciousness could find itself attached to (hosted by?) a different mind and just blithely continue on.
But the more I think about it, the more I think that’s at least reasonable, and possibly even likely.
A consciousness might be comparable to a highly sophisticated and self-aware frontend. Any range of data or software can be stored and run through it, and when new data or even a new piece of software is introduced, the frontend/consciousness can and will (if it’s working correctly) integrate it with the system, and it can review the data and software it’s overseeing and find flaws and (unless the ego subsystem intervenes) amend or replace it, and so on.
And viewed that way, and taking into account the likely mechanics of the whole thing, it really is possible and arguably even likely that it would be essentially content-neutral. It would make sense that while the experience of “I the audience” is itself a distinct thing, the specific details - the beliefs and values and memories and such that make it up - are just data pulled from memory, and it could just as easily pull any other data from any other memory (if it had access to it).
Fascinating…