19. Which shows wherein personal identity consists.
This may show us wherein personal identity consists: not in
the identity of substance, but, as I have said, in the identity of consciousness, wherein if Socrates and the present
mayor of Queinborough agree, they are the same person: if the same Socrates waking and sleeping do not partake
of the same consciousness, Socrates waking and sleeping is not the same person. And to punish Socrates waking
for what sleeping Socrates thought, and waking Socrates was never conscious of, would be no more of right, than
to punish one twin for what his brother-twin did, whereof he knew nothing, because their outsides were so like,
that they could not be distinguished; for such twins have been seen.
