5.20.pdf

Personhood Lecture VII (Final
Lecture): Transhumanism

and Computation

Review: Dennett

• Dennett introduces us to (what we might call) the location question.
• Asks: Where am I?

• Not an issue for most of us since our minds, brains, and bodies are in the same place.

• Dennett asks: What happens when they come apart?

• A sort of composition question.
• Answer must be of form:

• Some part or attribute of me, X, determines where I am located, and then question
is: where is X?

• Compare to Composition question proper:
• What parts or attributes of me determine my numerical identity?

• The two questions may have the same answer, but may have different answers.

Review: First Scenario

• Yorick Remotely Controls Hamlet

Review: Possible Answers

• In our previous discussion of the composition and persistence questions, we gave
three possible answers (plus their hybrids):
• Psychological Continuity (You are your mental properties—more soon!)
• Brain Continuity (You are your brain)
• Body Continuity (You are your body)

• Note: all compatible with dualism or physicalism
• We did not discuss a fourth possible answer, ‘soul continuity,’ which is incompatible with physicalism.

• I have suggested that none of these answers will help us with the location
problem.
• Psychological continuity is of no help because it begs question: where is mind located? Either

nowhere (Descartes/dualism) or brain (Armstrong/physicalism)
• Brain continuity yields bad results:

• Yorick (Dennett’s brain) is in Houston, but he can see himself digging up dirt in Oklahoma
• Body continuity yields bad results:

• Cannot explain how there is no such thing as a brain transplant (when a brain is taken from one body to
another, identity follows the brain).

Review: Better Possible Answers

• I have suggested two possible answers:
• [FIRST SUGGESTION] You are whatever body your brain is controlling

• Gives answer in terms of a body
• But not the same as basic body composition/continuity

• Doesn’t mention brains

• Which body you are is indexed to your brain
• Does mention—and essentially invoke—brains

• Dennett is his body (Hamlet) and is wherever his body is

• [SECOND SUGGESTION] You are your brain, and you are located where your body is
• Gives answers in terms of a brain
• Same answer as basic brain continuity for composition/persistence
• But distinguishes location from those two questions: the parts/attributes that make you you

(determine numerical identity) and the parts/attributes that determine location are distinct
• Dennett is his brain (Yorick) but is located where his body (Hamlet) is

Review: Other Scenarios

• Let’s see how well our two answers hold up to the other scenarios
Dennett envisions

• Scenario II: Yorick and Hamlet become disconnected
• FIRST: Dennett does not exist and is not located (since there is no body being

controlled by your brain)

• SECOND: Dennett exists and is brain (Yorick) but is not located anywhere.

• Scenario III: Original Body (Hamlet) dies, new body (Fortinbras) is
introduced
• FIRST: Dennett is Fortinbras, is where Fortinbras is

• SECOND: Dennett is Yorick, is where Fortinbras is

Review: Other Scenarios, Continued

• Scenario IV: Dennett’s original brain (Yorick) and an exact copy (Hubert) alternate control of same body (Fortinbras), but both receive sensory input

• FIRST: Dennett blinks in and out of existence, when exists, is and is located with Fortinbras

• SECOND: Dennett exists as Yorick, but blinks in and out of being located

• Not so great.

• Dennett’s Solution: The body controlled by Yorick OR Hubert

• Problem: removes special connection between Dennett and the brain he started with

• My solution:

• For two brains to differ in what they will do, either

i. Brains must start out different (be brains of different people)

ii. Brains must diverge in experiences (clones after separation)

• Neither i. nor ii. is true.

• Brain will be exactly the same.

• Yorick’s perspective when Hubert is in control:

• Receives same sensory information as when he is in control

• Body moves as it would if he were in control (since Hubert issues the same commands as Yorick would)

• From Yorick’s perspective, it seems like Yorick is in control.

• FIRST SUGGESTION, ALTERED (*): Dennett is body that is either controlled by, or seems to be controlled by, his brain (Yorick)

• SECOND SUGGESTION, ALTERED (*): Dennett is his original brain (Yorick), is located wherever body being controlled, or seeming to be controlled, by Yorick is.

• FIRST*: Dennett exists as, and is located with, Fortinbras

• Second*: Dennett exists as Yorick, is located with Fortinbras

Review: Wrapping Up

• Fifth Scenario: Yorick controls Fortinbras, Hubert controls new, qualitatively identical body
(Rosencrantz)
• Fairly straightforward for location question (same answers as first scenario)
• Interesting for persistence question

• But nothing we haven’t covered before (see: Fission I/Cloning, Teletransportation I/Replica)

• Sixth Scenario: Like fourth, but brains go ‘out of sync’
• Now condition ii for brain differences (have different experiences) is met
• FIRST*: Dennett exists and is located with Fortinbras when Yorick is in control, does not exist when Hubert is

in control
• SECOND*: Dennett exists as Yorick, is located with Fortinbras when Yorick is in control, is not located (is

nowhere) when Hubert is in control.

• “THANK GOD! I THOUGHT YOU’D NEVER FLIP THAT SWITCH! … the two brains drifted just a bit out
of synch … it snowballed, for I was in a slightly different receptive state for the input we both
received, a difference that was soon magnified. In no time at all the illusion that I was in control
of my body—our body—was completely dissipated” (Dennett, 68).
• Seems like endorsement of SECOND*!!

Susan Schneider

• Professor of Philosophy and
Cognitive Science, University
of Connecticut

• Editor of our Textbook

• First philosopher we are
reading who I have actually
met!

Key Concept: Transhumanism

• Someone who is enhanced by artificially made computational devices
integrated into the brain.

• Can ultimately lead to complete replacement of organic brain.

Transhumanism and Persistence

• Does transhumanism pose any novel problems for persistence?

• Schneider introduces two scenarios
• First scenario: mindscan

• Mental patterns are uploaded to a computer.
• “I shook my head. ‘You just scanned my consciousness, making a duplicate of my mind, right? … And since I’m aware of things

after you finished the scanning, that means I—this version—isn’t that copy. The copy … [is] free … But this me is still doomed’”
(Schneider, 268, quoting Sawyer) – said by a fictional terminal cancer patient who agreed to be uploaded

• Issue: does continued existence of uploaded copy count as original persisting?
• Same issue as Transportation I: Replica, except now Replica is made of computer, not organic material.

• Second scenario: neurological replacement
• Brain is replaced bit by bit with artificial components
• Issue: does a brain with X number of replacements count as original person persisting?

• Same issue as Parfit’s arbitrariness problem raises, except Replicated parts are now computers, not organic material.

• Both bring up same new issue: if psychological continuity is all that matters, does the new body
have to be qualitatively identical in terms of physical composition?
• Schneider finds a middle ground.

• It has to be qualitatively identical in more than just having causal links between thoughts, but not full physical composition.
• It has to be qualitatively identical in terms of computational composition.
• What does that mean?

Computation (and Representation)

• What is it for thought/mental stuff to be computational?

• Computations are transitions from an input and a starting state to an
output and an end state, with these transitions mediated by
representations.

• That’s a lot! Let’s take it one step at a time

Input/Output Relations

• A device that produces input/output relations is a device that receives
a signal (or object) and produces another, different signal (or object).

• Example: light switch.

• Input = Press button up, Output = Turn light on.

• Input = Press button down, Output = Turn light off.

State Transitions

• States describe the way something is at a time.

• Being hungry is a state of you (or your body).
• Knowing that you are hungry is a state of your mind.

• Being full is another state of you (or your body).

• When you go from being hungry to being full, you have undergone a
state transition.

Input/Starting State to Output/End State

• This one is probably easier to explain by example.

• Picture a coke machine.

• A coke machine has input-output relations: you put in a dollar, you get a coke.

• But it also has states.

• Each time you get a coke, it goes from having that many cokes to one less coke, e.g. 10 to 9 cokes.

• So a better way to describe it is: input a dollar and start at 10 cokes, go to output a coke and end with nine cokes.

• It can be described [I + SS] → [O + ES]

• [Dollar + n cokes] → [Spit out a coke + (n-1 cokes)]

• But what if starting state is zero cokes?

• Then it doesn’t output a coke!

• [Dollar + 0 cokes] → [Return dollar + stay at 0 cokes].

Representations

• A representation is something that stands for, or is about, something
else.

• Words are paradigmatic examples of things that represent.

• The word ‘dog’ represents this:

Transitions mediated by representations

• Old-school coke machines (like the one in the picture) didn’t represent how many
cokes were there.
• You gave it money, in the form of either coins or a dollar bill

• It determined if you had enough money by having a weight get to a certain point (for coins) or having the
dollar bill roll over a roller without jamming.

• (The old ones couldn’t tell the difference between a dollar and a $20 bill, they just relied on the commonsense
notion that no one would intentionally put a $20 bill in a machine to buy something that cost a dollar).

• The weight or roller triggered a mechanical action that dispensed a coke.
• It “knew” whether or not it had cokes to dispense by another weight under the stack of cokes.

• But a new soda machine, where cokes cost $2.50, might scan and create an image
of a bill to see if it is a $1 or $5 bill.
• The image would be checked for a match in a database, and a match would then send a

signal to dispense a coke.
• The words in red all indicate representational functions: scanning, checking, a database, an

image, a signal.

• The new coke machine, but not the old one, is performing computations.

Is Thought Computational?

• It sure seems like it!

• Consider
• Starting state = +
• Input
• Output
• End State –

• Transitions are right for computation.

• All of these items plausibly represent:
• Desires have objects (SANDWICH)
• Beliefs have statements that the person thinks are true
• Actions are represented in motor systems before being performed.

Computation and Physicalism

• Possibly (hopefully) during this presentation, you had a thought:
• But isn’t this just what Armstrong means by ‘causal roles’?

• Yes and no.

• A system with its components related by causal roles can be a
computational/representational system.

• But the basic material that makes up the states with those causal roles is like the
hardware.

• And the computational/representational theory cares only about the software.
• So, a “hard-core” causal-role theorist might say that thought is computational, but it has to be

implemented by a brain (the hardware matters).

• Armstrong himself is neutral between this position and Schneider:

• His view is that the human mind is in fact implemented by a brain but he is silent on whether it
must be implemented by a brain.

Computation and Psychological Continuity

• At the beginning of this unit, I made a remark I promised to explain later.
• I said: if you are a mind-brain identity theorist, then you will think that brain continuity is sufficient for

psychological continuity.
• But it is a further question whether it is necessary for psychological continuity.
• I.e. the brain continuity view, assuming identity theory, isn’t automatically the same as a psychological/brain

continuity hybrid view.

• I can now explain what I meant!
• If you are a “hard-core” identity theorist, and think the organic nature of the hardware matters, then brain

continuity is close to necessary for psychological continuity (if the mind is transferred, it must somehow be to
another brain).

• But if you are a software-only person like Schneider, or think the software can be run on multiple hardwares,
then even if identity is true, you can have psychological continuity without brain continuity.

• Because even though the mind in fact is the brain, it could in the future, be some other physical object.

• The computational theory of thought is also very helpful for psychological continuity in another
respect.
• It gives a much more substantial and sophisticated view of what psychological continuity amounts to than

‘causal dependence’ which is a very vague notion, and can be interpreted in many different ways.
• E.g. my computer’s overheating might cause it to break, its broken state is causally dependent on its prior functioning state.

But that couldn’t be psychological continuity.