Personal identity

Question 1

personal identity

Answer 1

what is it for a person at t1 to be identical to a person at time t2?

Question 2

necessary conditions

Answer 2

P is a necessary condition for Q just in case if Q is true then P must be true
eg. having a colour is a necessary condition for something being red

Question 3

sufficient conditions

Answer 3

P is a sufficient condition for Q just in case if P is true, then Q must be true

eg. being a human is a sufficient condition for being a mammal

Question 4

P –> Q

Answer 4

P is a sufficient condition for Q, also means that Q is a necessary condition for P

Question 5

spatiotemporal continuity

Answer 5

A at t1 is the same person as B at t2 just in case there is a continuous spatiotemporal path connecting A at t1 and B at t2
Objects not just having a spatial dimension, but also being stretched out through time

Question 6

objection to spatiotemporal continuity theory

Answer 6

suppose you get cremated after you die
there is a continuous spatiotemporal theory between you and and a pile of ash
but the ash is not the same person as you, it’s not even a person

Question 7

Another problem with spatiotemporal continuity theory - the prince and the cobbler

Answer 7

Prince and the cobbler switch bodies
question: who is who?
the prince’s memories and beliefs in the cobbler’s body is still the prince and vice versa
this would mean that the person in the cobblers body after the switch is identical to the prince and vice versa
so, spatiotemporal continuity theory is not accurate

Question 8

psychological continuity

Answer 8

A at t1 is the same person as B at t2 just in case they are psychologically continuous
there is a path connecting a person that there are very small changes in the psychological states of nearby members of the path, and that the earlier psychological states cause later psychological states

Question 9

problem for psychological continuity - duplication problem

Answer 9

there’s a scientist who makes a machine that transfers your psychology into another body
suppose that the scientist creates two people with your psychology
there would be multiple yous
but how can these duplicates be the same person, as they are numerically two separate people that exist in different places

Question 10

relations

Answer 10

S (sameness) is reflexive = x is the same as x, for every person x

S is symmetric = is x is the same as y, then y is the same as x

S is transitive = if x is the same as y, and y is the same as z, then x is the same as z

a relation with all these properties is an equivalence relation

Question 11

response to duplication problem

Answer 11

1. we could say that P0 is exactly the same as either P1 or P2
   problem: there is no grounds to say whether P0 is exactly the same as either P1 or P2 - we would have to postulate an unprincipled asymmetry
2. we could say that P0 is the same as both P1 and P2
   problem: we are forced to conclude that P1 and P2 are the same person - you can’t have a singular person multiply located
3. we could say that P0 is not the same as either P1 or P2
   problem: can’t be the case, because we do care what happens to both future persons that are the result of your duplication, and both these people can act on your earlier intentions

Question 12

Parfit

Answer 12

you are not strictly identical to your past selves
but it is still rational for past selves to care about future selves
this is because we are psychologically continuous
but we should give up on the idea that we have these relations because psychological continuity constitutes personal identity

Question 13

When we talk about survival and personal identity what we are talking about is there being some individual who stands in a certain relation of
psychological continuity to you as you presently are

Answer 13

Objection: Talk of psychological continuity presupposes identity

eg. you might think that someone can
only have a memory of something that happened
to them

But there are new terms that we can use to unproblematically pick out the psychological states that do matter to personal identity

Parfit calls a q-memory a psychological state of recollection that doesn’t require that one be
identical to the person to whom the event occurred

According to Parfit, it is continuity with respect to these states that matters

Note that psychological connectedness comes in
degrees

According to Parfit, then, personal identity—or rather what matters for personal identity— also comes in degrees