In everyday life, we're almost never in doubt as to which entities we want to consider "the same" person (like me-on-Monday and me-on-Thursday), but we can concoct science-fictional thought experiments that force [the Sorites problem](https://plato.stanford.edu/entries/sorites-paradox/) to come up. What if you could _interpolate_ between two people—construct a human with a personality "in between" yours and mine, that had both or some fraction of each of our memories? (You know, like [Tuvix](https://memory-alpha.fandom.com/wiki/Tuvix_(episode)).) At what point on the spectrum would that person be me, or you, or both, or neither? (Derek Parfit has [a book](https://en.wikipedia.org/wiki/Reasons_and_Persons#Personal_identity) with lots of these.)
In everyday life, we're almost never in doubt as to which entities we want to consider "the same" person (like me-on-Monday and me-on-Thursday), but we can concoct science-fictional thought experiments that force [the Sorites problem](https://plato.stanford.edu/entries/sorites-paradox/) to come up. What if you could _interpolate_ between two people—construct a human with a personality "in between" yours and mine, that had both or some fraction of each of our memories? (You know, like [Tuvix](https://memory-alpha.fandom.com/wiki/Tuvix_(episode)).) At what point on the spectrum would that person be me, or you, or both, or neither? (Derek Parfit has [a book](https://en.wikipedia.org/wiki/Reasons_and_Persons#Personal_identity) with lots of these.)