PART IV. Personal Identity
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17. Identity as the continuity of one’s own mind
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A natural criterion of personal identity is the continuity of the individual’s own mind. This is
stronger and more precise than requiring the same body, atoms, or physical configuration, all of
which change over a lifetime: molecules are replaced, appearance changes, neural configuration
shifts from moment to moment, and memories are formed and lost. The relevant continuity is
continuity of the mind as an ongoing process, which makes identity fundamentally diachronic rather
than configurational. A snapshot of a person at 10:00 and another at 20:00 can be different physical
configurations while belonging to the same continuing individual.
“Mind” must mean more than the mental contents present at a given moment; otherwise sleep,
anesthesia, unconsciousness, or memory loss would seem to create a new person. A more robust
formulation is:
Personal identity consists in the continuity of one’s own mind as an ongoing causal and
psychological process, rather than in the persistence of any particular material configuration.
Memory is a central component of that continuity because it carries much of a person’s accumulated
history: experiences, relationships, knowledge, commitments, preferences, beliefs, decisions, and
self-understanding. Memory is nonetheless not everything. A person can temporarily lack access to
memories without becoming numerically different, and losing a memory does not make the remembered
event cease to have happened or cease to have been part of that person’s history. What changes is
present access to part of that history. The view therefore has three interconnected layers:
• Mind continuity: the continuing individual mental process.
• Memory continuity: preservation of, and access to, much of the individual’s accumulated history.
• Causal continuity: the actual chain connecting earlier states of that mind to later ones.
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18. Identity under presentism
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Under CTGP only the present exists, so the claim “I am the same person I was ten years ago” relates
something that exists (the present person) to something that does not (the earlier person). The same
resources that answer the general question about past truths answer this one. That the present
person was the earlier person is grounded in the present world’s past-tensed properties; the person
is the present stage of a process whose history is also physically written into it now, as memory,
neural structure, habits, dispositions, and commitments.
Memory is evidence of this continuity, not what creates it. A present brain is not merely a
container of information about its past; it is one of the physical consequences produced by that
past. The resulting self-description is not “I am the person who remembers being me” but rather “I
am the presently existing continuation produced through the causal development of that earlier
individual.”
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19. Three kinds of continuity
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Three different continuities are easily run together:
• Physical continuity: a physical system continuously develops into its next state.
• Informational continuity: information about previous states remains encoded.
• Experiential continuity: successive conscious states belong to one stream of experience.
These can come apart. A hard drive can preserve informational continuity without experiential
continuity; a sleeping person can have reduced conscious activity while preserving physical and
informational continuity; and a perfect duplicate could share information and conscious organization
while still raising the question of numerical identity. CTGP’s extension to consciousness treats
causal continuity as one necessary condition for qualia-capable processes, while explicitly not
claiming to solve the hard problem of consciousness. In ordinary life the three continuities
coincide, which is why their distinctness is rarely noticed:
persistence of organization ≠ persistence of information ≠ persistence of experience
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20. Duplication: same information is not the same individual
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Imagine a technology that produces a second human with the same genome, brain structure, synaptic
strengths, relevant molecular states, memories, and personality. The duplicate wakes sincerely
believing “I am me, and I remember everything that happened.” There are now two physically distinct
causal continuations. A copied memory can preserve information about someone’s history without
transferring that person’s numerical identity:
same information ≠ same history ≠ same individual
A history can be copied without the historical individual being copied. More precisely, a person’s
present state can be reproduced without the history that produced it being reproduced as the same
history. The duplicate is not thereby “fake.” It would be a fully real conscious individual whose
present state happens to encode another person’s history.
Care is needed about why the copy differs, because the copy’s memories are not causally disconnected
from the original events. The duplicate’s causal chain runs past event → original brain → scan →
construction → duplicate’s memory. Both chains are causal and both reach back to the event; what
differs is the route. One stays inside a continuously living organism; the other passes through
measurement, encoding, and reconstruction. Causal ancestry alone therefore does not settle identity.
A child is causally descended from a parent without being the parent, and a duplicate causally
descended from a brain state is not, by that fact alone, the person whose brain it was. Causal
dependence explains why something exists and how it arose; it does not by itself say whether the
result is the same thing as its cause. An identity criterion must specify which kinds of causal
pathway constitute continuation of an individual rather than production of a new one.
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21. Branching shows that psychological continuity is not enough
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Suppose one person becomes two successors, each with the same memories, personality, and causal
ancestry up to the branching point. If psychological continuity were sufficient for identity, each
successor would be the original. But numerical identity is transitive: if A = B and A = C, then B =
C, and B and C are plainly two people. Therefore whatever relation preserves personal identity
cannot be unrestricted psychological continuity. This is the fission problem familiar from Derek
Parfit’s work, and it shows something structural: a relation can preserve everything that matters
psychologically while failing to preserve numerical identity.
The literary fiction work confronts this directly. In its fictional universe, a single continuing
existence can transition between different forms without being duplicated; non-duplication is a
world rule. That rule does real metaphysical work. It answers a question that psychological
continuity alone leaves open, namely what happens when continuity branches. In the actual world
nothing in known physics forbids branching in principle, so a real-world continuity view needs an
explicit non-branching condition or an alternative criterion.
Presentism sharpens the problem in an instructive way. After a split, both successors carry
identical records of the pre-split history, and records can be copied. Under CTGP the fact of which
successor walked out of the scanner and which out of the printer is still grounded, because it
belongs to the present world’s past-tensed profile. What can be lost is access: if every
distinguishing record is duplicated or erased, the fact may become unrecoverable. The duplication
case is thus a clean example of a fact that exists without being accessible to the observers it most
concerns.
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22. Transformation versus reconstruction
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Continuity of activity and continuity of identity are not the same thing. Temporary inactivity is
not necessarily discontinuity: during sleep, general anesthesia, or the deep hypothermic circulatory
arrest used in some surgery, during which the brain’s electrical activity can fall silent, the
brain’s organized physical structure remains intact, and later activity is causally continuous with
earlier activity through that persisting structure. “Uninterrupted electrical activity” therefore
cannot be the criterion.
Ordinary biological replacement preserves an ongoing causal organization: the existing organization
participates in determining how its own components are replaced, and at no stage does the person’s
complete state exist merely as information outside the person. Scan-and-rebuild procedures differ in
kind, because they insert a representation as an intermediate step. The original is measured, its
state is encoded, and another system is built from the encoding. If City A were converted into a map
and City B were then built from the map, no one would say that City A had traveled to B; something
informationally derived from A produced B. The same applies to persons: the information required to
reconstruct someone can survive without the individual whose information it is.
Past → present through causal continuity: transformation. Past → representation → new
instantiation: reconstruction.
One candidate criterion is therefore:
Personal identity consists in the uninterrupted causal inheritance of an embodied organization,
rather than in reconstruction from a representation.
Applied consistently, it yields the following verdicts:
• Sleep, general anesthesia, and temporary cessation of detectable brain activity with structure
intact: continuity.
• Gradual biological replacement incorporated into the existing organization: continuity.
• Gradual synthetic replacement incorporated in the same way: plausibly continuity, for the same
reason.
• Scan, destruction of the original, and reconstruction elsewhere: discontinuity, meaning the death
of the original and the creation of a new person. Many people find this conclusion hard to accept,
and it is the crux of Parfit’s teletransporter case.
• Scan and reconstruction while the original survives: two individuals, not one becoming the other.
• A perfect copy made from stored information: a new individual, however psychologically identical.
• The Ship of Theseus repaired plank by plank: plausibly the same ship, since the existing
organization continuously transforms rather than being rebuilt from a blueprint.
The criterion is not without difficulty. Consider neurons replaced one at a time by functional
equivalents until none of the originals remains. On a continuity reading, each replacement is
incorporated into an already existing organization. On a “micro-reconstruction” reading, each
replacement destroys one component and creates a successor from a description of it. Nothing in the
physical process announces which reading is correct. Between gradual molecular turnover and
whole-brain scan-and-rebuild lies a spectrum, and candidate dividing features include locality,
temporal continuity, preservation of causal organization, the absence of an informational
bottleneck, the absence of branching, or some combination. The framework has not established which
of these is decisive; what it has done is locate the precise unresolved variable. Whatever criterion
is chosen will settle the teleporter, the printer, gradual replacement, mind uploading, and the Ship
of Theseus at once.
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