Person A: "Black Mirror is a cool series, but at this point I think I can safely say that it is over-reliant on the "What if they could make a perfect self-aware digital copy of you?" plot device."And my further response --
Person B: "I agree but history will probably see it as a cautionary tale."
Person Me: "How can the impossible be a cautionary tale?"
Person B: "1984 was also thought to be impossible."
There is nothing logically impossible about '1984' -- and, in fact, it was happening under leftist regimes even as the story was being composed. So, if it was "thought impossible", it was thought so only by those who declined to think logically and reasonably about human beings.
On the other hand, it is logically impossible for a computer program to be self-aware, to be a *self* in the first place (*). Further, even if that weren't logically impossible, it would be a further impossibility for such a program to be a self-aware digital copy of a person/self (**). So, if a computer-program-as-a-self is thought to be possible, it is thought so only by those who decline to think logically and reasonably about persons and about computers.
(*) A computer, I mean the physical machine distinct from its programming, is no more capable of "hosting" a self than an abacus is; for, a computer *is* an abacus, very complex to be sure, but an abacus nonetheless, and nothing more. Meanwhile, a computer program is just a physical *representation* of *one* possible set of deterministic cause-and-effect transformations upon some possible data set or sets. If no data input is given to a program, no data output can be generated by the program.
(**) The so-called "perfect self-aware digital copy of you" would merely be *data* for such a program to read and perform operations/transformations upon; that is, it would be mere *representations* of certain facts about your and your history (and not any actual facts at all), used as input to such a program. That program, executing on that computer, reading *your* data, would no more be you (nor a copy of you) than a minute later that some program, executing on that same computer, reading *my* data, would be me (or a copy of me). Put another way, printing that data into a book does not cause the book to be a person (much less to be you). no matter how quickly someone flips the pages.