Mental Causation - PowerPoint Presentation

Slide1

Mental CausationSlide2

Supervenience

We say that the A-properties supervene on the B-properties when:

There cannot be a difference in the A-properties unless there is a difference in the B-properties.Slide3

Example

Economic properties supervene on physical properties:

It’s impossible for you to have more money than you now have, and yet for the world to be exactly the same physically.Slide4

Supervenience vs. Identity

Supervenient

properties need not be identical to their supervenience bases.

Many philosophers think that moral properties (right and wrong) are not physical properties. But many still believe that you can’t have two actions that are exactly alike physically, where one is right and the other is wrong.Slide5

Mental States

A common claim of both

epiphenomenalists

and

physicalists

is that mental states supervene on physical states.

You can’t have a difference in mental states without there being a difference in physical states (e.g. brain states or behavioral states). Slide6

Physicalism

For both the Identity Theory and (

Physicalist

) Functionalism, the supervenience of the mental on the physical is obvious.

If mental states are the same as brain states, then of course there’s no difference in the mental states unless there is a difference in the brain states: they’re the same thing!Slide7

Epiphenomenalism

For the

epiphenomenalist

, supervenience is (usually) true, even though mental states and brain states are different things.

Compare Chalmers’ Principle of Organizational Invariance: “any

two systems with the same fine-grained

functional organization

will have qualitatively identical experiences

.”Slide8

The problem of causal exclusionSlide9

Economic Properties

Economic properties (having $5) supervene on and are multiply realized by physical properties.Slide10

Having $5Slide11

Causal ExclusionSlide12

What causes the vending machine to give me a beverage: the fact that the thing I put in it is worth $5 (economic property) or the fact that the thing I put in it has certain physical features (physical properties)?Slide13

Physical Features

We’re tempted to say “physical features.” This is because:

Physically similar pieces of metal will also get me a beverage, even if they are not worth $5.

Many things that are worth $5 will not get me a beverage, even if I fit them through the payment slots (like checks for $5 or RMB worth $5HKD).Slide14

Functionalism

Functionalism says that mental states supervene on and are multiply realized by physical states (like brain states in humans or silicon chips in a robot).Slide15

Mental States Cause Behavior

Intuitively, the desire to raise my hand is the cause of my hand-raising behavior.

But we can ask the functionalist: is it the mental state (desire) or its realizer (neurons) that causes the behavior?Slide16

A Neurological Story

One reason to think it’s the

physical properties

is that we can tell a complete physical story about propagating nerve impulses that shows how the physical condition of our nervous system brings about our behavior.Slide17

The second reason is that we could have something with the same physical properties as the realizer of the mental property (desire to raise my hand), and it would also cause me to raise my hand, even if it didn’t realize the mental property. Slide18

Desire

/

Hand Raising

Stimulus

Response

Other Mental StatesSlide19

Not a Desire

/

Hand Raising

Stimulus

ResponseSlide20

World Causes Mental States

We could make the same argument regarding physical states causing mental states.

If a physical state of the world causes a belief X realized by a brain state, is it because X is a belief or because of X’s non-mental properties (location, weight, electrical charge) that the world causes X?Slide21

Mental or Physical Causation?

Light bounces off a dog and causes me to believe that there’s a dog.

Suppose X is the neural state that realizes my belief. Did the light bouncing off the dog cause X because X was a belief that there’s a dog?Slide22

First Reason

The first reason to think it’s the physical character of X that explains why it’s caused and not the fact that it realizes a belief is that we can tell a complete physical story about what happens without mentioning that X is a belief.Slide23
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The second reason, again, is that something with the same physical properties that is NOT a belief would still be caused by light bouncing off the dog.Slide28

Belief

/

Dog Bouncing

Stimulus

Response

Other Mental StatesSlide29

Not Belief

/

Dog Bouncing

StimulusSlide30

Exercise

Exercise: Figure out how the

same

argument would work for mental-state to mental-state causation.Slide31

Problem for Functionalism

Obviously, mental states cause actions, because they’re the mental states they are.

Obviously, states of the world cause mental states, because they’re the mental states they are.

Obviously, mental states cause mental states, because they’re the mental states they are.

But for Functionalism, all of these are false.Slide32

Epiphenomenalism

Does it help to be an

epiphenomenalist

?

No

, because

epiphenomenalists

don’t think mental states have causal powers. So they can’t explain the obvious facts either.Slide33

Possible Solution #1

Possible solution #1: Be an identity theorist.Slide34

Problem: Multiple RealizabilitySlide35

Possible Solution #2

Possible solution #2: Causal

overdetermination

.Slide36

Problem: Unlikely

Sometimes behavioral effects are causally

overdetermined

.

I might laugh both because Mr. X tripped and fell and because Ms. Y told me a funny joke, all at the same time.

But normally my laughing has only one cause.Slide37

Possible Solution #3: Everyone’s Problem is No

O

ne’s Problem

Being a wing supervenes on and is multiply realized by physical properties of things.

You can give

exactly similar arguments

that show that wings don’t cause things to fly because they’re wings. They just cause things to fly because of their physical configuration.Slide38

Possible Solution #3: Everyone’s Problem is No

O

ne’s Problem

So solution #3 says: it’s difficult to see how to get out of this problem.

BUT obviously there’s a way out, because wings cause things to fly.

THEREFORE, there’s obviously a way out of the causal exclusion problem. We just haven’t found it yet.Slide39

Problem

This isn’t really intellectually satisfying.

Furthermore, in certain cases, it’s not obvious that the supervening property has any causal relevance. Remember the vending machine!Slide40

Possible Solution #4: “Causal Relevance”

Define

causal relevance

as follows: a multiply realizable property P is causally relevant to X := P can be realized by physical properties A, B, C,… where A causes X, and B causes X, and C causes X, and…Slide41

Good LooksSlide42

Good LooksSlide43

Good LooksSlide44

Problem

Causal relevance ≠ causation.

If we say that multiply realizable properties can be causally relevant, but can’t themselves cause anything, the result is pretty weird.

It’s plausible that only the most basic, fundamental properties of physics are not multiply realizable.Slide45

Causal efficacy of contentSlide46

Breaking Glass

https

://

www.youtube.com/watch?v=IZD8ffPwXRo

Slide47

Representational Properties

An opera singer can (theoretically) break a crystal wine glass with her voice.

Suppose she’s singing about love. That doesn’t matter. The physical properties of her voice AND NOT what they mean are causally relevant/ causally efficacious. Slide48

Mental Representation

Later in class we’ll talk lots about mental representation. The general idea is that beliefs like the belief that there is a dog represent things (like the fact that there is a dog).Slide49

Mental Representation

We’d like to think that the representational properties of mental states are causally efficacious:

1. the belief that there is a dog and

2. the belief that all dogs are animals

causes

3. the belief that there is an animal

because

what the first two represent entail what the third belief represents.Slide50

The Opera Problem

But the case looks a lot like the opera singer. If beliefs are realized by brain states, what a brain state can do is determined by its physical properties– not by what it represents!Slide51

The Transitivity of CausesSlide52

Causal Theories of Representation

Represents