Mind and Body IBodies and Ghosts, Qualia, and Mind-Brain identity.

Brie Gertler A naturalistic dualist. The special character

of ‘mind’. The limitations of the

physical. The epistemic standing

of reports of mental states.

What is physicalism? Type identity theory: every type of mental

state is identical to some type of physical state.

Pain = C-fiber simulation (type/type identity) See fn 2 here: some defend token-token

identity, claiming only that every mental state is identical to some physical state. G. claims her argument addresses both.

Sensations G takes pain to be a sensation, i.e. something

like a ‘raw feel’, a kind of experience we typically have when we stub our toe or cut ourselves while chopping a pepper, or…

G emphasizes the strength of such identity claims-- they apply to all situations: if C-fiber stimulation is what pain is, you can’t have a pain without a C-fiber stimulation.

Consequences Empirical evidence can’t settle such

questions– we can correlate pain sensations with C-fiber stimulations, but that evidence can’t prove the pain and the stimulations are one and the same thing: Maybe the correlation is accidental. Maybe it reflects a causal link (C-fiber

stimulations cause pain). Maybe they (always) have a common cause.

Dualism A dualist denies the identity thesis. Mental states (and their types) aren’t physical states

(or state types). The sensation of pain, e.g., could occur without C-

fiber stimulation, even if (in fact) it never does. G’s case: She argues that we could experience pain

(have pain sensations) even if we had no bodies at all.

Possibility and Empirical Evidence G claims empirical evidence only ever shows us

what’s so, not what has to be so. This raises a question: if empirical evidence doesn’t

do the job, what kind of evidence does? G proposes that we rely on thought experiments,

combining imagination and ‘careful reflection’:

100 foot books vs. blue and orange ‘all over’. A married bachelor?

Concepts vs. imagination Imagination involves ‘pictures’ of a sort’;

concepts involve some kind of reasoning. But either way, we have a ‘conceivability

test’ for possibility: What’s conceivable is possible. What’s not conceivable is impossible.

So: is pain without a corresponding physical state conceivable?

Hubris Is my ability to conceive having this pain

without having a body at all really a good reason to conclude that it’s possible for me to have this pain without having a body?

All reasoning depends on concepts– so if they are unreliable guides, we’re in big trouble.

But sometimes we do give up on (or modify) concepts.

Particular concepts So are pain and physical concepts we can or

should rely on? G asks, are they sufficiently comprehensive?,

or:

“Are they ‘sufficiently clear and complete’, like your concept bachelor, or might they be confused or incomplete…?”

What do we mean by ‘X’? Physical = Non-mental? Physical = Part of a system of items and their

properties that we describe and explain in terms of physics (and chemistry and other such, purely physical sciences).

(The water & H2O problem…) Pain = ? : Unlike water, pain (says G.) ‘has no

hidden essence’. Infallibility: The feeling of pain is pain (no illusory

pain is possible) 291.

The special nature of mind Pain, for G., is transparent: if you’re in pain,

you are aware of it. To be in pain just is to feel that pain. All you need to do is ‘pay attention’ (look within your mind…)

The problem of other’s pain: I have no such awareness of another person’s pain– the essence of pain is missing from my evidence whenever I judge that someone else is in pain.

What’s hidden? The essences of physical substance (science explores

and discovers these). NOT our mind, or at least not our sensations or sense

data (our minds are immediately, infallibly aware of their character as sensations—including of the kind of sensation they are).

The inverted spectrum? How do we decide what does/doesn’t have ‘a hidden

essence’?

Mental Causation If the physical is causally closed (complete as

a system of explanation), then mental states (of a dualist sort) are explanatorily empty– they can’t explain or be explained by any physical goings-on.

Here G. goes Humean. Next, the chauvinism objection to ‘pain=c-

fiber stimulation’. (What about the same objection to phenomenal pain???)

Sellars

Philosophers talk about concepts. The point, however, is to change them.

Our concepts of minds and bodies have their uses– but we don’t have to simply accept them as they are– we should also think carefully about their origins.

In particular, our concepts of ‘sensations’ and sense data are clearly modeled on the basic sensible features of familiar objects and events.

Jackson on Qualia Frank Jackson has argued for decades that we have a

special knowledge or awareness of the character of our experiences that we could not have if they were (merely) physical events.

His piece here presents an argument for this: He claims that we could know all there is to know about a brain state without knowing what it feels like to the individual who is in that brain state, in his stories about Fred and Mary (298f)

Epiphenomena An event is epiphenomenal if it is caused by

some other events, but itself makes no difference to subsequent events.

Jackson suggests qualia are epiphenomenal. Otherwise, we’d be able to ‘get at them’ by

studying their causal effects—they would then be detected by our physics, not isolated and special as Jackson takes them to be.

Evolution An epiphenomenal effect could arise from evolution

even if it can’t be selected for, so long as it is a side effect of events/ processes that were selected for.

So qualia could regularly occur together with events that really are causally efficacious.

My ‘pain’ qualia may not cause me to pull my hand from the fire; my colour qualia may not cause me to stop at a traffic light.

This does put qualia in a very mysterious place…

Carruthers In this paper Peter Carruthers presents some

clearly formulated arguments in the area. He concludes in favour of physicalism and

mind-brain identity. In particular, Carruthers is very critical of the

complete knowledge arguments that Jackson proposes.

What do we know about qualia? Carruthers claims that what we know when

we know ‘what it’s like’ to see red (whether red1 or red2) is a practical sort of knowledge.

That is, it is the capacity to respond to some brain state by saying ‘I seem to see red’.

So it isn’t some kind of special, privileged awareness of some property that no physical thing could have.

Finally, on intentionality It seems to Carruthers that machines can show the

kinds of behaviour (searching, responding to the same thing in different ways depending on how it’s presented) that we take to demonstrate intentionality in humans.

This is pretty familiar today: we use intentional concepts to interpret what machines do quite naturally.

But Turing and Searle raise a question: When (if ever) should we take this seriously?