5.18.pdf

Personhood Lecture VI:
Where am I?

The Matrix and Reality

• When get to ‘reality,’ we will be asking two questions.
• First is: how do we know if we are in the real world or a simulation?
• Matrix is relevant, but there is a difference between the Matrix and the basic

question.
• The Matrix is not a ‘perfect’ simulation: It glitches, is evil, etc.
• Visually represented: The Matrix world is tinted green, the ‘real’ world tinted

blue.

What is Real?

• Second question: what is reality?
• Is virtual reality its own reality, or something inferior?

• “What is real? How do you define ‘real’? If you’re talking about
what you can feel, what you can smell, what you can taste and
see, then real is simply electrical signals interpreted by your
brain.” – Morpheus

• Think back to Descartes: if all that exists is you and the evil
demon, is that not “reality”?

Daniel Dennett

• Professor of Philosophy at Tufts University
• Student of Gilbert Ryle
• Major influence on Eric Schwitzgebel (my adviser)

What Question is Being Asked? (Edited)

• Not quite persistence question at play in Olson and Parfit
• Question is really the composition question: What am I?

• Possibly is composition question
• “Where am I?” is answered when “What am I?” is answered.

• But could be different sort of composition question
• The thing that makes you numerically identical to something else can be one thing

(a brain)
• And the thing that determines your location could be something else (a body).
• Also introduces the idea of ‘connectedness’ to composition questions. E.g.:

• You are essentially a brain that is embodied
• You are essentially a body that is connected to a brain in the right way.
• Makes some sense: if you are your brain or body when alive, you are neither when brain/body

are dead.

Meet the Players

• Physical Brain (Yorick): Original Body (Hamlet):

• Computer Brain Copy (Hubert): Duplicate Body (Fortinbras):

First Scenario

• Yorick Remotely Controls Hamlet

First Scenario (Edited)

• Yorick Remotely Controls Hamlet
• Where is Dennett?
• Dennett notes Conflicting Intuitions:

• Reason Dennett =/= Yorick
• If composition question answers location question in the way I have suggested (“Where am I?” = “Where is the stuff that I’m composed of

located?”)
• Can’t think of “here” as referring to inside the vat (where Yorick is).

• Reasons Dennett =/= Hamlet
• “If Tom and Dick switch brains, Tom is the fellow with Dick’s former body—just ask him; he’ll claim to be Tom, and tell you the most intimate

details of Tom’s autobiography” (Dennett, 60).
• If brain transplants are body transplants, then location question tracks brains rather than bodies.
• Further, if Dennett = Hamlet, then composition has nothing to do with anything mental.

• Possible solutions (not in reading):
• Dennett = The Body Controlled by Yorick

• Thus, Dennett = Hamlet, but for different reasons.
• Dennett would not be Hamlet if Yorick were put in another body.
• Dennett = Hamlet for reasons that have to do with the mental.

• OR Dennett IS (composition) Yorick, but is WHERE (location) the body controlled by Yorick is
• If this is right, then composition and location come apart.

Second Scenario

• Yorick Loses Remote Control of Hamlet

Second Scenario

• Yorick Loses Remote Control of Hamlet
• Dennett now has nothing to do with Hamlet.

• Dennett =/= Hamlet
• It’s now easy to think of ‘here’ as where Yorick is.
• So, Dennett = Yorick

• Not so Fast!

Combining First and Second Scenarios
(Edited)

• Say Dennett = Yorick in Second Scenario.
• Then you have a choice:
• Dennett is where Yorick is in first and second scenarios.

• But there were problems with Dennett being located where Yorick is in first scenario (‘here’
referred to location of Hamlet rather than Yorick).

• Dennett is where Hamlet is in first Scenario, where Yorick is in second scenario.
• While there were problems with Dennett is where Hamlet is in first scenario, they were

solvable.
• But there is a new problem.

• If Dennett’s location is with Hamlet in first Scenario, Yorick in second scenario, then when the
connection between Hamlet and Yorick was shut off, Dennett moved.

• Not only did he move, he did it instantaneously
• But nothing physical moved.

• Therefore, Dennett = something nonphysical (whose location corresponded first with Hamlet, then
Yorick).

• “I had stumbled upon an impressive demonstration of the immateriality of the soul based on
physicalist principles” (Dennett, 63).

Third Scenario

• Hamlet “dies;” Yorick now controls Fortinbras.

Third Scenario (Edited)

• Yorick controls Fortinbras.
• Possible solution: Dennett = immaterial soul that first corresponded in location with

Hamlet, then Yorick, then Fortinbras.

• Also, possible physicalist solution: deny possibility of disembodied brain.
• Some philosophers think that brains must be embodied to be minds.

• Here ‘embodied’ means connected to a body, not in a body.
• Assume Dennett = Body Controlled by Yorick.

• Then, Dennett = Hamlet (1st Scenario), then nothing (2nd Scenario), then Fortinbras (3rd Scenario).
• Assume Dennett = Yorick, and Dennett is located where that body is.

• Then Dennett = Yorick in all scenarios
• And Dennett is located with Hamlet (1st), then nowhere (2nd), then Fortinbras (3rd)

• This seems a bit better:
• If Dennett – body controlled by Yorick, then he does not exist in 2nd scenario
• If Dennett = Yorick, but is located where Body controlled by Yorick is, then he exists, but is nowhere

(not located) in 2nd scenario. That seems more plausible.

Fourth Scenario

• Yorick and Hubert alternate control of, and both receive input from,
Fortinbras.

Fourth Scenario (Edited)

• Yorick and Hubert alternate control of, and both receive input from,
Fortinbras.

• Dennett seems to think he (Dennett) is no longer necessarily related
to either Yorick or Hubert exclusively, but either one.
• That is, if Dennett were to adopt my formula (Dennett = the body controlled

by Yorick), he would opt for something like (Dennett = the body controlled by
either Yorick or Hubert).

• I disagree with Dennett on this point.
• I still think there’s something important about the connection between

Dennett and Yorick.
• Yorick was the brain Dennett had at the beginning!

Fourth Scenario, II (Added)

• Note that Yorick is receiving the same input from Fortinbras as Hubert, even when Hubert is in
control.

• Take an action performed by Fortinbras and initiated by Hubert.
• Suppose Fortinbras goes to the fridge and gets a sandwich because Hubert wants (Fortinbras to eat) a sandwich and believes

there are sandwiches in the fridge.
• Because Yorick and Hubert are identical, if Hubert has this belief/desire pair, then so does Yorick.
• Fortinbras therefore performed the same action that he would have performed if Yorick had been in control.
• Because of this parallel, it seems, from Yorick’s perspective, as if he is in control.

• This illusion of control happens when two brains are qualitatively identical. To be qualitatively different, they
must either:

• Start out as different brains (i.e. your brain vs. my brain)
• Have different experiences
• Neither is the case here!

• Instead of saying (Dennett = the body controlled by either Yorick or Hubert), I would preserve the
special connection with Yorick by saying either:

• Dennett = the body that sends information to Yorick, and seems, from the perspective of Yorick, to be under
Yorick’s control

• Dennett = Yorick, is located where body that sends information to Yorick, and seems, from the perspective of
Yorick, to be under Yorick’s control

Fifth Scenario

• Yorick and Hubert control different bodies (call the new body Rosencrantz).

Fifth Scenario

• Yorick and Hubert control different bodies (call the new body Rosencrantz).
• Which brain/body pair is Dennett?
• Dennett says: “there would be two people … one would be me, and the other

would be a sort of super-twin brother” (Dennett, 66).

• Also: “I would survive as long as either brain-body couple remained intact, but I
had mixed emotions about whether I should want both to survive” (Dennett, 66).

• What to conclude?
• From first quote, we can say that Dennett is one brain/body pair or the other, not both.
• From the second quote, first part (“I would survive…”) we can say that it doesn’t matter

which one is Dennett.

• (Again, I disagree: I think that composition does matter, and the original is
Dennett. But his conclusion is very interesting!).

Sixth Scenario

• Yorick and Hubert alternate control of Fortinbras, but fall ‘out of sync.’

Sixth Scenario (Edited)

• Yorick and Hubert alternate control of Fortinbras, but fall ‘out of sync.’
• From Yorick’s perspective, body would no longer seem under Yorick’s control

• Because the experiences of Yorick and Hubert would now differ (Yorick would have experienced being
‘offline)

• Result = When Hubert is in control, Yorick would feel like someone else is controlling his own body

• Dennett concludes here without explication, but this scenario is best explained by
what I have already suggested.
• When Yorick is in control, either:

• Dennett = The body that gives feedback to Yorick and seems to be controlled by Yorick
• Dennett = Yorick, located with the body (that seems to be) controlled by Yorick

• Disembodied brains do not count as minds. Thus, when Yorick is not in control:
• Dennett does not exist (if Dennett = body controlled by Yorick)
• Or Dennett is nowhere (if Dennett = Yorick, located with body controlled by Yorick).

• Dennett alternates between being Fortinbras, and not existing/being located!
• “THANK GOD! I THOUGHT YOU’D NEVER FLIP THAT SWITCH! You can’t imagine

how horrible it’s been … but now it’s your turn in purgatory!” (Dennett, 68).