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Consciousness and the Hard Problem (SACE Stage 2 Philosophy)

Syllabus dot point

“Explain the hard problem of consciousness and evaluate the knowledge argument and the conceivability of zombies”

7 min read

Quick answer

The hard problem of consciousness, named by David Chalmers, is the question of why and how physical brain processes give rise to subjective experience at all, the what-it-is-like quality of seeing red or feeling pain. Explaining the brain's functions, the easy problems, seems to leave this untouched. Two famous arguments press the point against physicalism. Frank Jackson's knowledge argument imagines Mary, who knows every physical fact about colour vision yet learns something new on first seeing red. The conceivability of philosophical zombies, physical duplicates with no inner experience, suggests experience is not fixed by physical facts. You need to explain the problem and evaluate these arguments and the physicalist replies.

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  1. What this dot point is asking
  2. The easy problems and the hard problem
  3. The knowledge argument
  4. Philosophical zombies
  5. Evaluation
  6. Assessment-style questions

What this dot point is asking

You need to set out the hard problem, explain the knowledge and zombie arguments against physicalism, and assess the leading responses.

The easy problems and the hard problem

David Chalmers distinguished the easy problems of consciousness from the hard problem. The easy problems, hard only in the ordinary scientific sense, concern explaining cognitive functions: how the brain discriminates stimuli, integrates information, reports states and controls behaviour. In principle these yield to standard neuroscience. The hard problem is different: even after every function is explained, there remains the question of why all this processing is accompanied by subjective experience at all. Why is it not simply going on in the dark? The felt quality of experience, often called qualia, seems to resist functional explanation.

The knowledge argument

Frank Jackson dramatised the gap with the case of Mary. Mary is a brilliant scientist who has lived her whole life in a black-and-white room and learned, through black-and-white screens, every physical fact about colour and the brain. One day she leaves the room and sees a red rose for the first time. The argument: Mary learns something new, namely what it is like to see red. But she already knew all the physical facts. So there are non-physical facts, facts about experience, and physicalism is false.

Physicalists reply in several ways. The ability reply of Laurence Nemirow and David Lewis says Mary gains not new factual knowledge but new abilities, to imagine, recognise and remember red, which is know-how rather than knowing-that. The acquaintance reply says she gains a new way of knowing an old fact, not a new fact. Each tries to preserve physicalism by denying that anything genuinely new is learned at the level of facts.

Philosophical zombies

A philosophical zombie is a being physically and functionally identical to a normal person but with no conscious experience whatever; all is dark inside. Chalmers argues that such zombies are at least conceivable, and that if they are conceivable they are possible, and if possible then consciousness is not fixed by, and so not identical to, the physical facts. This is the conceivability argument against physicalism.

The standard reply attacks the move from conceivability to possibility. Daniel Dennett argues that we cannot really conceive of a complete physical and functional duplicate that lacks experience; we merely think we can, because we underestimate what full functional duplication would involve. Others argue that conceivability is a poor guide to genuine metaphysical possibility, citing cases where what seems conceivable turns out impossible.

Evaluation

These arguments form the strongest contemporary case against a fully physical theory of mind. Their power is that they target not this or that detail but the apparent explanatory gap between objective physical description and subjective experience. The physicalist responses are not knockdown, but they expose a key assumption: that we can read metaphysics straight off what we can imagine or off what knowledge feels like gaining. Positions range from property dualism, which accepts the arguments and adds non-physical properties, to illusionism, which holds that the very seeming of an explanatory gap is itself a feature to be explained physically. A strong answer weighs whether the arguments establish a real metaphysical gap or only an epistemic and conceptual one.

Easy problems versus the hard problem

The hard problem is not any particular function of the brain but the existence of subjective experience at all. Keeping it distinct from the easy problems of function is what lets you state why the knowledge and zombie arguments target physicalism rather than mere neuroscience.

Assessing an anti-physicalist argument

Both arguments turn on a contested inference; the marks come from testing it. Work it in steps.

Step 1: separate the hard problem from function

State that the target is subjective experience itself, not any brain function, so neuroscience does not automatically answer it.

Step 2: lay out the argument's structure

For Mary: she knows all physical facts, learns something new, so not all facts are physical. For zombies: conceivable, so possible, so consciousness is non-physical.

Step 3: attack the key step

Press the conceivability-to-possibility move (Dennett) and the new-fact claim (ability and acquaintance replies).

Step 4: judge the kind of gap

Conclude whether the argument shows a metaphysical gap or only an epistemic one, weighing property dualism against illusionism. Testing the contested inference and judging the gap is what the top band rewards.

Common errors

Treating qualia as just brain states. That is the physicalist conclusion, not a neutral starting point; the arguments are designed to challenge it.

Sliding from conceivable to possible without comment. This inference is the most contested step in the zombie argument and must be assessed, not assumed.

Confusing the hard problem with the mind-body problem generally. It is a specific challenge about subjective experience, distinct from older debates over substance dualism.

Assessment-style questions

Questions on this dot point, each with a worked answer, written by ExamExplained. Philosophy has no written exam, so use them to check your understanding before your assessment tasks.

Practice15 marks
"Physical science cannot explain consciousness." Critically discuss the hard problem with reference to the knowledge argument and philosophical zombies.
Show worked answer →

A 15 mark essay needs the hard problem stated, both arguments, the replies and a defended conclusion.

State the hard problem. Distinguish the easy problems of function from why any processing is accompanied by subjective experience.

Give the knowledge argument. Mary learns what red is like despite knowing all physical facts, so there are non-physical facts.

Give the zombie argument. Conceivable physical duplicates without experience suggest consciousness is not fixed by the physical.

Evaluate replies. Ability and acquaintance replies to Mary; Dennett on conceivability and possibility.

Conclude. Defend whether the gap is metaphysical or only epistemic. Markers reward both arguments assessed and a defended thesis.

Practice12 marks
Evaluate the knowledge argument against physicalism.
Show worked answer →

A 12 mark essay needs the argument explained, tested and judged.

Explain it. Mary knows every physical fact about colour yet learns something new on seeing red, so physical facts do not exhaust the facts.

Object. Press the ability reply (she gains know-how, not new facts) and the acquaintance reply (a new way of knowing an old fact).

Judge. Conclude whether Mary learns a new fact or only a new ability or mode of access. Markers reward the ability and acquaintance replies engaged and a defended verdict.

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Sources & how we know this

ExamExplained