1. Michael Lacewing enquiries@alevelphilosophy.co.uk
The zombie argument
Michael Lacewing

2. Substance and properties
A substance is an entity, a thing, that does not depend on another entity for its continued existence.
It has ‘ontological independence’.
Substances are what possess properties.
Properties can’t exist without substances
They depend on substances to exist.
Substances persist through changes in properties.

3. Substance and property dualism
Substance dualism: there are two sorts of substance, mind (or soul) and matter
Minds can exist independent of bodies
Mental properties are properties of a mental substance
Property dualism: there is just one sort of substance, physical substance
Mental properties are properties of a material substance, but they are fundamentally distinct from physical properties

4. Physicalism The fundamental nature of the universe is physical:
the properties identified by physics form the fundamental nature of the universe;
All properties are ontologically dependent on physical properties (identity or supervenience)

5. Property dualism
Physical properties don’t form the complete fundamental nature of the universe
Chalmers on consciousness
‘Easy’ problem: explaining functions of consciousness in physical/functional terms
‘Hard’ problem: explaining the phenomenal properties of consciousness
These may not be analyzable in terms of function or physical structure

6. Possible worlds
A ‘possible world’ is a way of talking about how things could have been.
Propositions describe ‘states of affairs’.
Propositions can be true or false.
A proposition that is true describes the way things are; the actual world.
A proposition that is contingently false describes a possible state of affairs, a way things could be but aren’t.

7. Possible worlds
Possible worlds are distinct from one another depending on what we are supposing to be true in that world.
Things have different properties in different possible worlds.
Different things exist in different possible worlds.

8. Philosophical zombies
A zombie, in the philosophical sense, is a physical replica of a person, but with no phenomenal consciousness
Zombies are not possible in the actual world
The laws of nature correlate physical properties with consciousness
Are they possible in a different possible world?
A world that is physically identical to ours, but without consciousness
Are zombies ‘metaphysically’ possible?

9. The argument
The idea of a zombie isn’t a logical contradiction – so they are conceivable.
If they are conceivable, then they are possible.
If consciousness were ontologically dependent on physical properties, then zombies would be impossible.
Because zombies are possible, consciousness is not ontologically dependent on physical properties, so physicalism is false.

10. The argument It is conceivable that there are zombies.
If it is conceivable that there are zombies, it is metaphysically possible that there are zombies.
If it is metaphysically possible that there are zombies, then, contra physicalism, physical properties do not determine all mental properties.
Therefore physicalism is false.