Thursday night, the new NBC series Awake premiered. The show follows a detective after a tragic car accident and his experiences with his wife and son. In one world, his son has died and he copes with his wife. In the other, his wife has passed and his son remains. Adding to the confusion is the fact he seems to pass between these worlds when he goes to sleep in the other one; each world suggests the other is a dream. Which of them, if either, is real?
Perhaps it is the case that they are both real and the show is ultimately depicting a kind of modal realism. That is to say, all logically possible worlds actually exist, and the main character is experiencing two of them. He is oscillating between them and retaining his memories. This would rely on the idea of transworld identity. Roughly, transworld identity says that there are some essential properties of a person, and these properties hold across all possible worlds in which that person appears. Hence, because of the indiscernability of identicals, that person just is who he is in every possible world; they aren’t different persons. The reason this take on Awake would rely on transworld identity is because if a person is not who he is across all possible worlds in which he exists, then the detective would not be the same person in both possible worlds. He would be two separate persons.
Transworld identity suggests there is something more to personhood than mere matter. It suggests there is an “essence,” or that collection of essential properties that define a person. This essence would not include wholly external or wholly contingent factors. So, for instance, an essence would not include the property of being tall (or being any specific height). It would include being a person, being a moral agent, and so on.
A criticism of modal realism is that it would result in logically contradictory states of affairs. It would be true that a is actual, and it would be true that not-a is actual, if there were to be more than one actual world. A possible defense is to say that “John performs A in C” and “John performs not-A in C,” describe two different people. Basically, the two possible worlds have “John” and refer to a person very much like the other, but they are two different persons. However, if transworld identity is true, then this is, strictly speaking, false, and there cannot be more than one possible world that is actual.
Further, transworld identity is consistent with the Christian view of having a soul. That can be what personhood is: a concrete expression of the collection of abstract but essential properties. Transworld identity is an interesting concept, but highly intuitive. It seems obvious that our performing of an action differently than we in fact did, or growing one inch taller than we in fact did, would not make us a different person. Rather, it would be us—but a different version of us! What do you all think?
 It should go without saying I do not believe in modal realism. However, it would be an entertaining show!
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