Where it sits
After thirty years of dedicated science, this dial has not moved much.
Tell it apart
| Aspect | Phenomenal consciousness | Access consciousness |
|---|---|---|
| Definable by function | No | Yes |
| Measurable | Contested | Yes |
| The hard problem | This one | Not this one |
| Reportable | Not necessarily | By definition |
Ned Block's split: access consciousness is information being available to a system's other subsystems — functional, tractable, roughly 'awareness'. Phenomenal consciousness is the qualitative feel. Conflating the two is how the hard problem gets accidentally declared solved.
What it doesn't mean
In 1998 the neuroscientist Christof Koch bet the philosopher David Chalmers that the neural mechanism producing consciousness would be identified within 25 years. On 23 June 2023, at the Association for the Scientific Study of Consciousness meeting in New York, Koch conceded. The results of a structured adversarial collaboration between integrated information theory and global neuronal workspace theory were announced at the same event: mixed, partial support and partial trouble for both, no winner.
Chalmers's point is a difference in kind. The easy problems — discrimination, integration, reportability, attention, the wake/sleep difference — are all functionally definable and yield to standard cognitive science. In Chalmers's own words, it 'is hard precisely because it is not a problem about the performance of functions'. Explain every function and the residual question stands: why is performing them accompanied by experience?
What it really means
In 1998 a neuroscientist made a bet with a philosopher.
Christof Koch wagered Chalmers that within 25 years the neural mechanism producing consciousness would be identified. Not the full theory — just the mechanism. A quarter century seemed generous for a field moving that fast.
On 23 June 2023, at the Association for the Scientific Study of Consciousness meeting in New York, Koch conceded. At the same event, the results of a structured adversarial collaboration were announced — a formal contest between the two leading theories, integrated information theory and global neuronal workspace theory, with the predictions registered in advance. The outcome: partial support and partial trouble for both. No winner.
That is the state of the art, and it is worth sitting with, because it is not a story about scientists failing. It is a story about a specific kind of question.
Chalmers named it at Tucson in 1994 and put it in print in 1995. He separated the easy problems — discrimination, information integration, reportability, attention, the difference between waking and sleep — from the hard problem. The easy ones are not easy; they are merely the kind of thing science knows how to do, because each is defined by a function, and explaining a function means finding a mechanism.
The hard problem is different in kind: why is performing any of those functions accompanied by experience at all? You could, in principle, explain every function completely, and the question would still be standing there.
The word itself carries an accidental joke. Conscious comes from Latin conscius — knowing-with, from com- 'with' and scire 'to know'. Its root sense is shared knowledge, awareness held between people. It turned inward in the 1630s to name the one thing that, so far, cannot be shared at all.
The Philosophy world's page on consciousness sets out the main theories and the three broad ways of closing the gap between matter and experience.
Where it comes from
Latin — knowing, aware (com- 'with' + scire 'to know')
Literally 'knowing-with'. The Latin root is social — awareness shared with another — before it turned inward in the 1630s.
- 1630s
The noun is first attested meaning 'internal knowledge'; the sense 'state of being aware of what passes in one's own mind' follows in the 1670s.
- 1995
David Chalmers publishes 'Facing Up to the Problem of Consciousness', putting into print the hard problem he had named a year earlier, in a talk at Tucson.
In real life
- Under general anaesthetic you lose consciousness: one moment you're counting backwards from ten, the next you're in recovery with no sense that any time has passed.
- A thermostat registers the temperature and responds to it, yet few people think there is anything it is like to be a thermostat — and that gap is the puzzle.
- You can trace exactly how red light reaches the eye and is processed by the brain, and still not have explained why seeing red feels like this.
Questions
Q01What is the hard problem of consciousness?
The question of why physical processing is accompanied by subjective experience at all, as distinct from the 'easy' questions of how the brain performs cognitive functions. Chalmers framed it in 1995.
Q02Did anyone win the Koch–Chalmers bet?
Chalmers. Koch conceded publicly in June 2023 that the neural correlates of consciousness remain unclear, and both agreed the search continues.
Q03Do scientists agree on a theory of consciousness?
No. There is no agreed-upon theory, and the 2023 adversarial collaboration between the two leading candidates produced no clear winner.
Sources
- Chalmers, Facing Up to the Problem of Consciousness (JCS 1995).
- Quanta Magazine — What a Contest of Consciousness Theories Really Proved (2023).