"Where Am I?" is an entertaining science fiction story that raises deep philosophical questions about personal identity.

The Cast:

• The narrator voice ("Dennett")

• Yorick: Dennett’s original brain

• Hubert: a computer that instantiates Yorick

• Hamlet: Dennett’s original body

• Fortinbras: Yorick’s second body and later Hubert’s first

Scientists approach the heroic Dennett to go on a secret mission to disarm a nuclear device named STUD. The mission could be highly dangerous to Dennett’s brain (though not his body), so the scientists have figured out a way to send Dennett’s body (Hamlet) on the mission while leaving behind his brain (Yorick) in the lab.

Heroic Dennett agrees to go. His brain is surgically removed from his body and placed in a vat. His brain still controls his body via implants and transmitters and antennae. With the flip of a switch, the connection between his brain and his body can be severed. With another flip of the switch, the connection can be re-established.

Where is Dennett? Where are Dennett’s thoughts tokened?

1. Dennett is wherever Hamlet is.
2. Dennett is wherever Yorick is.
3. Dennett is wherever he thinks he is.

Dennett finally goes to disarm the STUD. Unfortunately, Hamlet is destroyed in the process. Yorick lives on in the vat, but is now deprived of all sensory input, and goes to sleep for a year.

Then the scientists establish a connection between Yorick and a new body Fortinbras.

Is Dennett now dead? What would the character Gretchen Weirob say in Perry's Dialog on Personal Identity and Immortality? Gretchen Weirob is offered the chance to have her intact brain implanted in a different body (say, Mary's). Gretchen says she would refuse the procedure, because the resulting person would not necessarily be Gretchen. There is no compelling non-circular reason to claim that the person with Gretchen's brain is Gretchen with a different body; you could just as easily say the resulting person is Mary with a different brain. So in Dennett's story, by Gretchen's argument, Dennett has really died, since his body has died. The person walking around now (Yorick controlling Fortinbras) is Fortinbras with a new brain.

What does Dennett say on the subject of his death? Nothing at all. It is perfectly clear to Dennett that he cannot have died if death means permanent cessation of consciousness; he is obviously still conscious. But who exactly is conscious: Dennett-Yorick or Fortinbras-Yorick? Dennett the narrator still has Dennett's memories, so he says he is the same person as he's been all along: he is the same Dennett-narrator, whose point of view is now from "inside" Fortinbras. Point of view alone seems to determine the "who".

Dennett (now Yorick controlling Fortinbras) visits Yorick and learns about Hubert. Hubert is a computer program that is an exact bit-for-bit real time copy of Yorick. (If the brain is a computer and the mind is the program, as strong AI says, then the mind must be capable of "multiple realizations," e.g., in hydraulic equipment, or the cast of millions, or another computer. Hubert is an instantiation of Yorick’s program.) Hubert could easily be connected by implants and transmitters and antennae to yet another body ("some Johnny-come-lately Rosenkrantz or Guildenstern").

Dennett doesn’t want Hubert connected to another body, for two reasons:

1. He doesn’t know which would be him, and can’t think of any good argument in favor of one or the other (since neither is connected to his original body — this would stump Gretchen too, I think). His intuition is that both would be him (but of course, this contradicts the common view that identity implies uniqueness).
2. Although it might be kind of cool to have two bodies, Dennett fears the "social consequences" (212).

On the other hand, it seems wrong to Dennett to just leave Hubert detached from any body, since Hubert is arguably him.

So Dennett and the scientists agree to a plan: Dennett will utilize both Yorick and Hubert, occasionally switching from one to the other. Dennett alone has the controls. This solution is a version of the "same stream" argument: both Yorick and Hubert are supposed to embody "the same stream" of Dennett’s memory and consciousness. Dennett decides to switch channels in the course of the talk to demonstrate how seamlessly the two "brains" work in conjunction with his (Fortinbras) body.

Then mayhem begins, and the play ends. Where is Dennett?