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

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.