PHL471: Parfit on Identity and Continuity
Parfit on Identity and Continuity
- Parfit is concerned to address whether we really need a
theory of identity to answer important questions about the
self, or rather whether we can get by with something else.
He will argue that we can drop identity and use psychological
continuity as our important and relevant theoretical concept.
- First, note that we should not be surprised that some
things lack answers to all identity questions. We might conclude
there is no interesting answer to a question like, is England
the same country before the Magna Carta and after WWII. So, we
should be open to the prospect that some human personal identity
questions might have no answer.
- One argument that there should be answers to all our PI
questions could go something like this: each experience
either is mine or is not mine. So, there should always be an
answer about whether some agent (which presumably has
experiences) is me or not.
- Some thought experiments can cast doubt on this reasoning.
- What about division? Suppose that you could divide your
brain. (Parfit means literally cut in half, but let us avoid the
questions about which side has what skills, and stick with fission
like an ameoba -- thus, assume you have an ameoba-like brain.)
Then, each brain is transplanted to a new body. What happened to
you? Are you (1) destroyed, (2) on of the two people, (3) both of
the two people.
- (1) Seems wrong. If you didn't have the other copy, you'd
be very inclined to say you survived.
- (2) is arbritrary -- which one are you?
- (3) is our best option. But now note that this wrecks
talk about personal identity, since there are two different
objects that I want to say are the same person as one past
- Another thought experiment: I divide my mind, and then
reunite the parts after each does some task. This suggests
that the person has two series of thoughts, and then they reunite.
There are two problems for PI: what is it to have two series
of thoughts? What is it for them to reunite?
- Parfits suggestion: give up the language (that is, theory)
- But so much of our planning and so on is framed as being
about identity. Parfit's response: this is true but is a
contingent fact arising because in the past we did not have
splitting and fusing minds. So, identity in some sense
reliably tracked issues of survival and psychological
continuity. But the prospect that we can start to divide the
two things (continuity and identity) allows us to see that
the former is not the essential thing at issue for most of
our concerns (e.g., survival).
- Definition: q-memory: memory of something that may or
may not be my past experience (that is, memory that does not
- Definition: psychological connectedness: an intransitive
relation of having overlapping memories.
- Definition: psychological continuity: a transitive
relation of having a series of overlapping memories.
- Parfit considers other thought experiment cases. Fusion: one
person joins into two. Extensive division: one person has a chain
of ancestral and future "selves." Fissing and fusing folks: persons
who divide and join. Immortal bodies with shifting personalities.
In all such cases, Parfit argues we see psychological connectedness
coming in matters of degree.
- Parfit wants to generalize: for each
of us, our connnection to future selves is a matter of degree.
Personal identity, an all or nothing relationship, must be abandoned
as the relevant criterion for our concerns with things like survival,
and replaced with psychological connectedness.
- In conclusion, Parfit makes a fascinating claim.
Much of ethics is concerned with questions of egoism and
altruism. Should I be concerned about myself alone, or
others to some degree? But all of such considerations are
based on assumptions of clear personal identity. If my
future self is me only to some degree; if it has some
psychological connectedness with my current self, but only to
some degree; then it seems that egoism rests on a mistake.
As a result, I should be attracted more towards accounts that
weigh all interests equally, over those that tell me to weigh
my interests alone or more heavily -- for after all, those
future interests are "mine" only to some variable degree.