Property Dualism

This is my favourite topic in all of Philosophy A-Level.

Qualia: The subjective, felt qualities of experience, what it’s like to taste, see, feel, or smell something.
Supervenience: A relationship between two sets of properties where the higher-level properties depend on the lower-level properties such that there cannot be a difference in the higher-level properties without some difference in the lower-level ones.
Interactionism: The mind can interact with the physical world and the physical world can interact with the mind
Epiphenomenalism: The physical world can cause mental states but mental states cannot cause changes in the physical world

The painfulness of pain is an example of qualia. Everyone knows what pain feels like, but you can’t describe that feeling to someone who has never felt it. That feeling is only accessible to you and everyone experiences it differently

Qualia

Qualia can be a tricky concept to understand, but basically they are just your subjective experiences, what it is like to sense something.
They are how you interpret the stimuli you encounter: what it’s like for you to taste, smell, see, or feel something.
Qualia are often described using adjectives, for example, the redness of an apple when you look at it, or the softness of a dog when you stroke it.
Important: these qualities are not properties of the object itself, but properties of your experience of that object.
Knowledge of qualia is sometimes called phenomenal knowledge.

Interactionism vs Epiphenomenalism

Interactionism is that mental can cause physical and the physical can cause the mental (like in substance dualism):

- mental (tiredness) causes physical (go to bed).
- physical (touching hot pan) causes mental (feeling of pain).
Epiphenomenalism is that causal interaction only works one way, the physical causes the mental and not the other way around.
Most Property Dualists are Epiphenomenalists as they believe that qualia are caused by physical things but that qualia doesn’t cause anything itself.
Epiphenomenalism avoids the interaction problem of substance dualism because it does not have to explain how the mental causes the physical, because that does not happen in Property Dualism

Good to know for AQA: You can use Property Dualism as a counter to Substance Dualism and say it is better because it avoids the interaction problem

Credit: Davidl, Wikipedia, CC BY-SA 3.0 license.

David Chalmers & The Zombie Argument

A philosophical zombie is a being that is physically and functionally identical to a normal human, but lacks any qualia.
A zombie will have physical reaction, like saying “ouch!” when stabbed for example, and its brain will fire in exactly the same way as a normal human’s. However there is no inner experience of pain.
We can adapt Descartes’ conceivability argument to support the zombie argument for property dualism:
Philosophical zombies are conceivable.
If zombies are conceivable, then they are metaphysically possible.
If zombies are metaphysically possible, then qualia must be non-physical (because you can have all the physical facts without the qualia).
If qualia are non-physical, then property dualism is true.
Therefore, property dualism is true.
Why this supports Property Dualism: it tries to show that physical facts are not enough to account for consciousness. The Zombies can be explained fully physically, but they are missing something - the non physical part. This means consciousness is not explained physically.

Problem: Zombies are not Conceivable

The zombie argument might only seem convincing because we currently lack a complete physical explanation of qualia.
If qualia are ultimately physical, then two physically identical beings must have identical qualia.
In that case, philosophical zombies would be inconceivable, and the argument fails to establish property dualism.

Problem: Zombies are not Metaphysically Conceivable

This criticism focuses on the idea that zombies are not metaphysically conceivable. What this means is that things that are metaphysically conceivable have to be consistent with something's nature within reality.
Say we have 3 types of possibilities:
Logical possibility: anything that does not involve a contradiction.
Physical possibility: anything compatible with the actual laws of nature.
Metaphysical possibility: anything that could exist given the essential properties of things.
Some philosophers claim that phenomenal properties, like consciousness, are essential properties of some physical thing. In which case it’s not metaphysically possible for the same physical thing to have different phenomenal properties because you have contradicted and removed an essential property.
In other words, a physical duplicate without qualia, like the zombie, is metaphysically impossible in the same way water without H2O is metaphysically impossible (h20 is an essential property of water).

Problem: Metaphysical Possibilities Tell us Nothing

Okay, so let's say that zombies actually are metaphysically possible. Does that actually give us any information about how the world actually is?
Arguably, even if something is metaphysically possible this does not tell us anything about how things actually are in our world. All this does is tell us what could be the case, not what is actually the case. There are lots of metaphysical possibilities, but it does not necessarily mean it is true.
Something simply being possible does not prove objective reality.
Simply put: metaphysical possibility cannot by itself lead to conclusions about the actual nature of reality.

Frank Jackson's Knowledge/Mary argument

Mary is confined to a black-and-white room, is educated through black-and-white books and lectures relayed on a black-and-white television. In this way she learns everything there is to know about the physical nature of the world. She knows all the physical facts about us and our environment, in a wide sense of ‘physical’ which includes everything in completed physics, chemistry, and neurophysiology, and all there is to know about the causal and relational facts consequent upon all this, including of course functional roles. If physicalism is true, she knows all there is to know.
It seems, however, that Mary does not know all there is to know. For when she is let out of the black-and-white room or given a color television, she will learn what it is like to see something red, say. […] Hence, physicalism is false.

Mary knows every physical fact about colour while confined to her black and white room.

She has complete physical knowledge, including all the physical facts about how humans perceive colour.

However, Jackson argues that when Mary leaves the room and sees colour for the first time, she learns something new, what it is like to experience colour.

Since she already possessed all the physical facts, whatever new knowledge she gains must be non-physical.

Therefore, physicalism is false, because there are non-physical facts: facts about subjective experience, or qualia.

Problem: Ability Knowledge

Remember we have three types of knowledge:
Ability knowledge is knowledge how.
Acquaintance knowledge is knowledge of.
Propositional knowledge is knowledge that.
We can say that Mary gains something new when she leaves the
black and white room, but deny that it is new non-physical knowledge. The
Ability Hypothesis says Mary gains ability knowledge, not new propositional facts.
Just as someone only learns how to ride a bike by actually doing it, Mary only gains new abilities when she sees colour for the first time. She now knows how to imagine red or distinguish red experiences from green ones.
These abilities depend on the physical functioning of the brain, so they do not show that physicalism is false.

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Problem: Acquaintance Knowledge

We can agree that Mary learns something new, but still say this new knowledge is physical. It is knowledge by acquaintance rather than new non-physical facts.
For example, you might know many facts about Al Pacino, but you don’t know him personally unless you’ve met him. His friends are acquainted with him, but their knowledge isn’t non-physical.
Similarly, Mary can know all the physical facts about red without being acquainted with red, because her own brain has never had to interpret the wavelength it was given and "meet" red.
When she sees red for the first time, that property occurs in her brain, and she becomes acquainted with redness.
So Mary gains new acquaintance knowledge, not new non-physical facts, so physicalism can still be true.

Problem: New Knowledge, Old Fact

We often understand the same physical fact in different ways. For example, “there is water in the glass” and “there is H₂O in the glass” technically mean the same thing, but someone could know the first without knowing the second. They are two different concepts of the same thing.
There are plenty of things that are known in different ways. This is down to Ontological Reduction (which comes up in Type Identity Theory). There is only one fact (a physical fact), but two different ways of conceptualising it.
Before leaving the black and white room, Mary knows all the physical facts about redness, but only in theoretical terms. When she sees red for the first time, she gains a new phenomenal concept, a way of thinking about the same physical fact from a first-person perspective.
So Mary does not learn a new non-physical fact. She simply gains a new way of understanding the same physical reality.

Problem for Property Dualism: Introspective self-knowledge

Epiphenomenalism says that the brain causes both our physical outputs and our qualia.
For example, touching a hot stove causes a brain state, and that brain state causes motor and sensory neurons to make us pull our hand away (physical output) and also gives us the painful experience (qualia). The qualia itself causes nothing.
But if qualia have no causal powers, then they cannot play any role in producing our knowledge of them.
How could we ever know our own qualia if our thoughts and beliefs are all caused only by brain states, not by the qualia themselves?
Basically, how are our qualia communicating to us that we are having that experience. Something with no causal powers should not cause anything at all - even knowledge.

Problem for Property Dualism: The phenomenology of mental life

The previous problem showed that qualia may in fact have causal powers as it can cause us to have knowledge of our mental states, but this objection shows that qualia also seem to cause other mental states.
For example, if someone is in constant chronic pain, this may cause them to feel sad.
The means that the horrible feeling of being in pain (qualia) caused the mental state of sadness (qualia).
But property dualists say that qualia have no causal powers. Which means that it wouldn’t be possible for pain qualia to cause sadness.
But it seems obvious that qualia do cause other mental states, and so epiphenomenalism must be false.

Problem for Property Dualism: Evolution

Evolution leads to genetic mutations and over millions of years, the environment selects genes that give some benefit
Mutations which lead to greater survival are beneficial for survival
in the physical world. Before the Industrial Revolution, most peppered
moths were light coloured. This helped them blend in with pale trees,
so birds couldn’t easily spot them. When pollution darkened the trees
with soot, the light moths became highly visible and got eaten more
often. A dark-coloured mutation already existed in the population,
and in the new environment, these dark moths were now camouflaged
and survived better.
But, if epiphenomenalism is true, there would be no evolutionary benefit to having qualia because epiphenomenal qualia doesn’t have any causal effect.
Brain states certainly have benefit, they cause physical outputs that lead to an increased chance of survival. So why would we need qualia as well as this?
So we are left with two options: qualia does have some useful causal role, otherwise we wouldn’t have evolved it OR, there is no need to it at all and everything is explained via some physical benefit. Both options prove Property Dualism false.