I almost ended up doing a paper on the problem of personal identity, but ended up getting distracted by the controversy surrounding Wittgenstein’s theory of objects instead.
Until I’ve worked out my thoughts on the problem of personal identity, I thought I’d share a number of places in which this topic is intelligently dealt with in science fiction.
This show is the prequel to Battlestar Galactica. In it, the main character, Zoe, creates a sentient computer program that exists in a virtual reality internet world and is an identical copy of herself with her physical appearance, memories, experiences, and behavior patterns.
After the real Zoe dies, all that is left is the copy which is placed into a robot by the father. It’s pretty clear in Caprica that Zoe and the copy are not the same person, but the question (philosophically) of what distinguishes the two is a fruitful line of inquiry, as this example eliminates both memory and experience as what grounds personal identity.
In this film, at least one of the major characters has definitely been cloned and given the experiences of a deceased person and told that they are that person. Similar to Caprica, the difference being that the artificial Zoe in Caprica knows she is not the real Zoe. I don’t think this is the main philosophical issue in this film, but the personal identity problem is certainly a major theme.
Star Trek: The Next Generation-“Second Chances”
In this episode, it is discovered that—in a transporter accident—a copy of Will Riker was created and left stranded on a planet for several years. Because the process of teleportation involves dematerialization and re-materialization, the whole idea poses a problem for the body theory of personal identity (and the possibility of an empirical solution to this problem).
Big Bang Theory
The problem is comically described by Sheldon in an episode of Big Bang Theory:
Ghost in the Shell (Film and T.V. Show)
Another problem for the body theory of personal identity is presented in the anime film (and subsequent television series) Ghost in the Shell. Here, Aristotle’s classic ship example is applied to the theory of personal identity. Aristotle asks: if a ship that has been refitted so many times that none of the ship’s parts are original, is it the same ship?
The main character, Major Motoko Kusanagi, was born a human but her organic body parts have been replaced entirely by cybernetic components—even to the point that her brain is entirely cybernetic. This raises the question: if you replace the right side of the brain with a cybernetic component compatible with the left side of the brain and this cybernetic brain takes over the functions formerly handled by the right side of the brain—and then you also replace the left side of the brain and it takes over the functions of the left brain, is the original person still alive?
What’s interesting here is that even after undergoing all of these transformations, it is implied that there is still possibly a continuity of experience (although this is left as something for the viewer to decide for themselves).
Another Question Ghost in the Shell makes me ask myself:
Is it possible for me to have been a different person? Could I have been born as an animal in another possible world?
This question does not necessitate that we assume the existence of an immortal soul for it to make logical sense, I don’t think.
The continuity of experience can be successfully isolated in a way that would be satisfying to most strict empiricists and positivists. This is done through the transcendental argument Kant makes in the B Deduction of the Critique of Pure Reason.
To make an argument that is similar, but more elementary and rough in form, we could say:
For everything I think, it makes sense to say that “I think” it. For every experience I have, it makes sense to say that “I am having this experience.” Also, I perceive this as an experience “I” am having. Also—insofar as this is possible in each case—my experiences seem to flow in a unity. For experience to be like it is, all of experience must be unified and mine. Therefore, there must be a Transcendental Unity of Apperception that is the condition for the possibility of subjective unified experience.
Following a version of Kripke’s rules for making a modal argument, let’s isolate the subject and the transcendental unity of all of his experiences as a constant. In our possible world, however, we will change his body, his identity, and all of his experiences to that of a squirrel.
So far, I see no problems with the logical consistency of this. The problem is, all I think it shows is that it is possible to imagine reincarnation and possible to entertain questions like “what would it be like to be born as a different person?” It doesn’t isolate, however, a rigid designator of personal identity because what has been isolated (the transcendental subject) is subject to a number of critiques on phenomenological, existential, and neuroscientific grounds.
Regardless, I think the answer to the problem of personal identity includes something like the flow of experience, in addition to some other things I will not mention here for sake of brevity.