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 a thinking thing The body is essentially spatially extended

Mind Matter Materialism Dualism Two Options

Descartes... top dualist

Arguments for dualism (and against materialism) 1. Psychic phenomena 2. Epistemological argument: From Introspection 3. Epistemological argument: From Leibniz’s Law

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:

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.

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.

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.

Epistemological argument from 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].

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.

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!

Many other cases: Mark Twain = Samuel Clements Water = H 2 0 I can know that there is water in the glass but not know that there is H 2 0 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. …

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.

Causal Interaction argument If mind has no mass or place… how does it interact with body? This is a major argument against Descartes.

Queen Elizabeth of Bohemia: Killer causal interaction objection

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

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.

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

“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.

Outer physical event 1 Brain event 1 Brain event 2 Outer physical event 2 Mental event Interactionist dualist picture

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.

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.

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 …..