← See the axis · The enigma of consciousness
ArgumentThe hard-problem argument
Explaining every function of the brain leaves untouched the question why they are accompanied by experience: the sign that experience is one more fact.
Supports
Chalmers · "Facing Up to the Problem of Consciousness" · 1995
- To explain, in science, is to show by what mechanism a function is carried out: how the organism discriminates colours, memorizes, controls its behaviour, reports on its own states. These , as they are called by contrast, are hard, but we know what their solution would look like.
- Suppose them all solved, down to the last circuit. One question remains, perfectly intelligible, and it is the : why is all that work accompanied by experience? One can describe a system that discriminates, memorizes and reports without yet having said what it is like for it.
- When a question stays open although the explanation has said all it could say, its object was not what that explanation described: structure and function do not contain experience.
- Yet experience varies strictly with the state of the brain, and no one dreams of denying it: that dependence is as solid a fact as the gap.
Therefore So experience is a further fact about the world, irreducible yet tied to the brain by a law of nature: a without miracle, where nothing is added to matter but what it regularly produces.
How far does this reasoning convince you?
Not at all
Entirely
Deepenings
A psychophysical law
- The strict dependence of experience on the brain rules out 's separate soul: there are not two substances here, one of them pushing the other.
- It does not, however, rule out that a fundamental psychophysical law links certain physical states to certain experienced states, as other laws link mass to gravitation. Such laws physics does not derive: it records them and posits them at the outset.
- Experience would then be a fundamental ingredient of the world, on a par with charge or spacetime, to be built into the theory rather than derived from it.
Therefore This dualism is naturalistic: it does not add a soul to the world, it adds a line to the list of nature's laws.
How far does this reasoning convince you?
Not at all
Entirely
The philosophical zombie
- Conceive a zombie, a being physically identical to you, atom for atom, speaking and acting exactly as you do, but with nothing being lived: no one home inside.
- The description involves no contradiction: the vocabulary of physics speaks only of structures and motions, and one can follow that description through without ever meeting a feel.
- If such a world is possible, then the complete physical truth does not suffice to fix the facts of experience: two physically identical worlds could differ in what is felt in them.
Therefore Experience therefore does not follow from the physical: it is added to it, which is exactly what property dualism says.
How far does this reasoning convince you?
Not at all
Entirely
Put to the test
Objection