Saturday, March 3, 2012

Awake, Modal Realism, and Transworld Identity

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.[1] 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?

[1] It should go without saying I do not believe in modal realism. However, it would be an entertaining show!

All posts, and the blog Possible Worlds, are the sole intellectual property of Randy Everist. One may reprint part or all of this post so long as: a) full attribution is given (Randy Everist, Possible Worlds), b) all use is non-commercial, and c) one is in compliance with the Creative Commons license at the bottom on the main page of this blog.


  1. I would say they are two different persons. The only reason it seems more plausible in the show is because there is a continuous psychological experience. That would not seem to be the case in a more "realistic" transworld scenario. Don't you think? I think we would end up in intuitively difficult situations, like those proposed by Derek Parfit. Are you familiar with the teletransporter problem? Let me know if not and I can describe it.

  2. Hey Dr. Mike, long time no hear from! :)

    I don't believe in transworld identity because of the show. After all, I certainly don't believe in modal realism. I just find it utterly incredible that if I had been a quarter of an inch taller, or a tenth of an inch shorter, that I would be a different person (this is what a denial of transworld identity entails). Secondly, if this afflicts transworld identity it afflicts identity simpliciter. For there was a time when I was a tenth of a inch shorter. If it follows that from such a property I am a different person, it follows that I am a different person from moment to moment; indeed, I am a nearly infinite number of persons, so that "I" is really just an indexical representing the collection of all the various persons, who differ. However, if there is a solution to the "temporal identity" problem, it can be applied to the "transworld identity" problem as well. There are, in fact, at least two solutions. The first involves essential properties. The second is that indentity relations necessitate that there be no time such that each of the two subjects have different properties at that time; a similar move can be made with respect to possible worlds (cf. ).

  3. I know you don't believe in it because of the show! I was just saying that if modal realism is true (and I also don't believe it is), then I would deny the different "yous" would be the same person. That much seems clear. To answer the more difficult question (to me, anyway) about transworld identity would require me to have a more settled notion of identity. I really don't know what to think about that beyond thinking that continuous psychological experience seems more important than physical identity.

    On a slightly related note, have you ever read The First Person by Anscombe? You might enjoy it. She argues quite controversially that 'I' is not a term that refers to anything.

  4. HI Mike. Yes, that's what I was getting at in the article; that if modal realism is true, we ought to deny transworld identity (it was only after publishing this that I discovered that Lewis indeed denied transworld identity, and for the same basic reason, so I am proud of myself for this one night lol). I have not read that book, it sounds interesting! I wish I had more time. Between my full time job, the wife, graduate classes, church, and the's getting hard to study as much as I would like.


Please remember to see the comment guidelines if you are unfamiliar with them. God bless and thanks for dropping by!