Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic...

24
Knowledge and Reality Lecture 2: Dualism

Transcript of Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic...

Page 1: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Knowledge and Reality

Lecture 2:Dualism

Page 2: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Dualism: what is it?

• Mind and body are different basic substances

• They have different essences

• The mind is essentially a thinking thing

• The body is essentially spatially extended

Page 3: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Mind

Mind

Matter

MatterMaterialism

Dualism

Two Options

Page 4: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Descartes... top dualist

Page 5: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Arguments for dualism(and against materialism)

• 1. Psychic phenomena

• 2. Epistemological argument: From Introspection

• 3. Epistemological argument: From Leibniz’s Law

Page 6: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Psychic phenomena argument

• ‘science’ of parapsychology.

• The alleged phenomena of telepathy, mind-reading, pre-cognition, telekenesis, clairvoyance.

• These seem hard to explain physically.

• So? Can we infer dualism?

• But:

Page 7: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

• It is not clear that such phenomena are real. • In laboratory conditions, they have never

been confirmed. • What about out of the body experiences?

Where we seem to rise up out of our body and look down? Near-death experiences also seem to be like this.

• We may even seem to decide to return to our bodies.

Page 8: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

• Reincarnation? Many think they were once Napoleon? (Can they all have been?) They seem to recollect a past life.

• The fact that one seems to be looking down on one’s body does not mean that one is; similarly with remembering being Napoleon.

• They are merely apparent psychic phenomena; so there is no good pro-dualist argument here.

Page 9: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Introspection argument

• We can be aware of my headache directly but not be aware of our brain states; therefore my headache is not a brain state.

• But perhaps introspection does not reveal how things are. It reveals that I have a headache, not what it is.

Page 10: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Epistemological argumentfrom Leibniz’s Law

• Mental states are known immediately (my own at any rate).

• Brain states are not known immediately; they are known scientifically, by observation.

• So, hence, therefore, … mental states are not brain states. That is [MS≠ BS].

Page 11: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

• Many arguments for dualism turn on the way we know about the mind.

• It seems like a general principle assumed…• X is F Y is not-F so X ≠ Y• For example:• David Cameron is wearing a hat; the man in front of me is not

wearing a hat; so the man in front of me is not David Cameron. • This argument form seems ok.• ‘Leibniz’s law’ is that identical things have all their properties

in common. Surely this includes the property of being known a certain way.

Page 12: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

• But, in fact, the inference is fallacious in belief or knowledge contexts.

• For example, consider the argument:

• Lois Lane knows that superman can fly; • Lois Lane does not know that Clark Kent can fly• therefore • Clark Kent is not Superman?

No!

Page 13: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

• Many other cases:• Mark Twain = Samuel Clements• Water = H20• I can know that there is water in the glass but not know

that there is H20 in the glass.• So… similarly, it seems that it is possible that mind

and body are known in very different ways… but that does not show that they are not identical.

• There is more to this argument… Descartes has a more subtle argument. That’s all for now though. …

Page 14: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Arguments against dualism (and for materialism)

• We will spend most on the causal interaction argument.

• Other arguments are… • … dualistic stuff is only negatively characterized.

Mental substance is characterized by what it is not… not spatial, not material etc. It seems ghostly. Are souls in space? Could there be a science of this stuff?

• … dualism also has trouble with evolution; it seems that mind emerged from matter.

Page 15: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Causal Interaction argument

• If mind has no mass or place… how does it interact with body?

• This is a major argument against Descartes.

Page 16: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Queen Elizabeth of Bohemia:

Killer causal interaction objection

Page 17: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Queen Christina of Sweeden: Made Descartes get up too early… which killed him…

Page 18: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

• Action, perception, … lots of examples …• One bangs one’s head…• One drinks alcohol, …drugs such as tea and coffee• If mind and matter are radically different

substances with different essences. how can they interact?

• How can brain damage affect mental functioning?• If mental states are (=) states of the brain, this is

easily understood. If not, not.

Page 19: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Possible reply?

The materialist argument is that interaction is a mystery for the dualist… but perhaps the dualist can reply …

Page 20: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

• “Yeah, ok, it’s mystery… that is, it is basic form of causal interaction just like gravity, which the materialist admits as basic”. Something has got to be basic, so what’s the problem? Like gravity, mind-brain interaction happens, and we cannot explain it in other terms. It is basic.

Page 21: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

Outer physical event 1

Brain event 1 Brain event 2

Outer physical event 2

Mental event

Interactionist dualist picture

Page 22: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

But! Note that:• On this picture, some events in the brain are not

caused by previous brain events.• But! (a) No brain scientist has ever noted the

existence of physically uncaused brain events. • And (b) this conflicts with what is called the

‘causal closure principle’. This is the idea that the causes of physical events are entirely physical; that physical events can be explained in purely physical terms.

Page 23: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

The causal closure principle: why believe it?

• It is said to be a very general scientific principle, that regulate science... In science we look for physical causes of physical events.

• This policy has been successful, in many areas of science.

• Examples: exploding toaster, or rash on leg. No cause? Or we just don’t know it?

• The casual closure principles seems to be at the heart of physical scientific theory. So dualism conflicts with a basic and well-tried principle of physical science.

Page 24: Knowledge and Reality Lecture 2: Dualism. Dualism: what is it? Mind and body are different basic substances They have different essences The mind is essentially.

So, it seems we should be materialists. For in order to meet the causal interaction objection the dualist violates the causal closure principle, which there is independent reason to believe.

… but materialism is not without its own problems…

as we shall see…

……. Next week …..