— 342 —
      §19. This may shew us wherein personal Identity consists, not in
the Identity of Substance, but, as I have said, in the Identity of con-
sciousness, wherein, if Socrates and the present Mayor of Quinborough
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.
Locke Hum II, 27, §19, p. 342