The Knowledge Argument

A-Consciousness andP-Consciousness (cont.)

Review

Access Consciousness: a state wherein informational mental content is available to reasoning and rational control of action

Phenomenal Consciousness: qualia, raw feels, “what it is like”

Possible relationship between A- and P-Consciousness

1) They are distinct in concept and separable in reality

There are actual cases of P- without A-Consciousness or A- without P-Consciousness, e.g. blindsight, background noise

2) They are conceptually distinct but empirically inseparable

In humans, P and A consciousness always go together, but we can imagine in other creatures they could come apart, e.g. zombies (A without P) and floaters (P without A)

3) They are not even conceptually distinct

P-consciousness is a necessary component of A-consciousness. A-consciousness necessarily feels the way it does. Zombies are inconceivable.

Other Characterizations of Consciousness

1) Self-Consciousness

Sometimes consciousness is defined as self-consciousness.

In other words, it is claimed that consciousness is an awareness of the world in relationship to one’s self, so that a concept of self is necessary for consciousness.

“Perhaps consciousness arises when the brain’s simulation of the world becomes so complete that it has to include a model of itself” (Dawkins 1981)

Self-consciousness = a higher-order consciousness

Self-Concept:

self vs. environment self vs. others

A kind of Access Consciousness

Can a creature have P-consciousness withoutself-consciousness?

Block says, obviously yes.

Most people say yes. Some rare philosophers say no.

Mirror test for self-consciousness:

Meant to show if animal/person is self-conscious.

Spot put on forehead of dog/chimp/baby and dog/chimp/baby put in front of mirror.

If they react to mirror appropriately, e.g. touch their own forehead, they are said to be self-conscious.

Dogs, cats, birds fail.

Chimps, elephants, dolphins pass.

Babies pass after 1½ years old.

Are dogs nevertheless conscious?

2) Monitoring-Consciousness

Consciousness is internal monitoring (proposed by Lycan)

Consciousness consists of a scanning of internal mechanisms that monitor perception, psychological states, etc. and integrating the information received

What about laptop computer that contains internal monitoring program?

Lycan: consciousness is a spectrum. Laptop computers are a little bit conscious.

Block: This is only A-consciousness, not P-consciousness

Thought Experiments aboutColor Consciousness

Philosophers of consciousness love to talk about color.

Experience of color perception is a prime example of qualia.

The experience of color is P-consciousness, but the ability to discriminate color is a function of A-consciousness

But, these thought experiments are really about consciousness -- color is just an example.

These thought experiments could be reformulated to be about tastes, smells, sensations or sounds.

1) The Inverted Spectrum

A precursor to the knowledge argument.

First proposed by John Locke in 17th century

Imagine that you see colors in exactly theopposite way as I do.

Where I see green, you see red,where I see yellow, you see blue, etc.

You and I still use color words in exactly the same way – we agree that the sky is blue, even though we experience the color of the sky differently.

Color discrimination functions the same in both of us.

Argument against functionalism:

Since color perception in both of us is functionally the same, but our qualia is different, functionalism about qualia must be wrong.

Argument against physicalism:

If no physical investigation can show that our color experience is different, physicalism must be wrong.

Objection to the inverted spectrum scenario:

Is it really possible for color experience to be inverted with no behavioral (functional) differences?

Consider: The sky appears “orange” (as you see orange) to me, but I say that the color of the sky is cool, soothing and peaceful, and it reminds me of refreshing water, bluebells and bluebirds.

Can I really see “orange” and have this response?

What is it like for me to see “orange” for blue? Is it like seeing orange is for you, or is it like seeing blue is for you?

Dennett: “qualia” is no more than the combination of physiological responses, associations and reactive dispositions caused by a stimulus.

2) The Knowledge Argument

Frank Jackson

“Epiphenomenal Qualia”

1982

“Qualia freak”

Argues that physicalism is false, and qualia is epiphenomenal.

What “physicalism” means:

Everything is physical

All (correct) information is physical information.

All facts are physical facts.

Remember: supervenience

The mental supervenes on the physical.

Thoughts, feelings, ideas, qualia all supervene on the physical.

What “physicalism is false” means:

There are non-physical facts.

OR

There are non-physical properties.

Jackson’s claim:

Qualia is non-physical.Anything non-physical can have no effect on the physical

world (because of causal closure)

Hence, qualia is epiphenomenal

FredThe knowledge argument has two parts:

1) Fred2) Mary

Fred is the lesser known.

Fred can distinguish two completely distinct colors in objects that we call “red”. He calls them red1 and red2.

For Fred, these colors are as distinct as blue and yellow are for us.

He can use this ability to sort (e.g.) tomatoes reliably into two categories. The categories look the same to us (i.e. red), but he can always tell them apart.

We are colorblind with regard to red1 and red2.

We can never know (except by direct experience, i.e. a partial brain transplant) what red1 and red2 are like.

Physical investigation cannot tell us what red1 and red2 are like, so these concepts are non-physical.

Is this the same as we cannot tell what it is like to be a bat?

No. We share most types of subjective experience with Fred, but we cannot know what this particular subjective property is like to experience. We cannot even know what it would be like for us to see red1 or red2.

Two possible class-level graphs for Fred’s red qualia

Color

Blue Yellow Red

Red1 Red2

John distinguish

Red1 Red2

Color

Blue Yellow

Freddistinguish

MaryMary is the second and more famous part of the Knowledge

Argument.

Mary Imprisioned

Mary is imprisoned in a black-and-white room

with a black and white TVMary’s skin, blood, etc. dyed grey?let’s just say Mary is colorblind

Mary is a brilliant scientist.

She learns all the physical facts about colors and the neurophysiology of vision (how we see color), including:

• which wavelength combinations from the sky stimulate the retina (Jackson’s example)

• how the stimulation of our eyes causes the brain state changes that result in the speech act “the sky is blue” (Jackson’s example)

• what changes in brain states occur when we see or imagine color and how these changes affect all other brain states (Inglis’ elaboration)

When Mary comes out of the room (or has surgery to give her color vision), she sees colors for the first time.

Is she surprised?

“Oh, that’s what blue looks like!”

Does she learn something?

Jackson: Yes, obviously she learns something!

Mary freed

The Argument

P1 Mary knew all the physical facts about color vision

P2 Mary learned something new about color vision

Conclusion: What she learned was not a physical fact.

Hence: There are non-physical facts.

Facts about qualia are non-physical facts.

Mary

all physical facts about color visionknow

some fact about color vision

learn

not subClassOf

all physical facts

subClassOf

Modal-level graph for Mary’s new fact

Responses1) Mary doesn’t learn anything new

Jackson is begging the question.

Jackson says Mary knew all the physical facts, and yet learned something new. Obviously, this presupposes that all physical facts do not cover all possible facts.

You can object that P1 is impossible. It is impossible for us to learn all the facts about human visual processing

Or, if you accept P1 and you don’t beg the question and you assume that there are only physical facts, then you conclude ¬P2: Mary doesn’t learn anything new.

If Mary doesn’t learn anything new, why does it seem like she would learn something new?

It is very hard to understand what it would be like to know all the physical facts about the perception of color in human beings.

Because we cannot imagine what it is like to know all the physical facts, our intuition lets us down.

We cannot now imagine what complete physical knowledge of visual processing will allow us to understand in the future.

Perhaps brain fMRI studies can detect differences between colorblind people and people with normal color sight(also see http://www.ugr.es/~setchift/docs/2006-phantom_colors_in_color_blind_synaesthete.pdf).If there are significant differences, then once Mary sees colors, her fMRI should change to the ‘normal’ category.

2) The ability response

Mary does learn something new, but what she learns is not a fact.

Mary learns know-how.

Not all knowledge is factual knowledge. Some knowledge is know-how, e.g. how to ride a bicycle.

Mary learns how to recognize colors, how to imagine and remember them.

Perhaps this could again be detected by brain fMRI studies.

3) Mary doesn’t learn any new facts, but she learns old facts under a new presentation.

Mary learns no new facts about color.

She learns to experience old facts in a new way.

Knowing from a subjective point-of-view and knowing from an objective point-of-view are two different ways of knowing, but can both be knowledge of the same facts.Mary could objectively know how fMRIs look like for people with normal color sight, yet not subjectively know color qualia until after her surgery.

Related argument: subjective facts are also physical facts, but can only be known subjectively. So, she does learn new facts, but physicalism is not false.

Jackson’s change of heartIn 1982, Jackson thought that the knowledge argument

proved that qualia was non-physical and supported epiphenomenalism.

Later, he changed his mind. He decided that physicalism is most likely correct, and the knowledge argument is misleading, but still interesting as a challenge to be answered – how can it be wrong and yet seem so right?

In 2003 (http://consc.net/neh/papers/jackson.htm), he wrote:

“Most contemporary philosophers given a choice between going with science and going with intuitions, go with science. Although I once dissented from the majority, I have capitulated and now see the interesting issue as being where the arguments from the intuitions against physicalism—the arguments that seem so compelling—go wrong.”

Readings for next weekFocus:

Daniel Wegner (2003), “The mind's best trick: How we experience conscious will”. http://web.gc.cuny.edu/cogsci/private/wegner-trick.pdf

Zelazo & Thompson, “Is Thought Unconscious?”, in The Cambridge Handbook of Consciousness, pp. 357-359.http://books.google.com/books?id=o9ZRc6-FDg8C&printsec=frontcover&dq=The+Cambridge+Handbook+of+Consciousness#PRA1-PA1,M1

Extra:

Levy, Neil, (2005), “Are Zombies Responsible? The Role of Consciousness in Moral Responsibility”.http://au.geocities.com/neil_levy/Documents/articles/consciousness_MR.pdf