Being awake and aware — of yourself, your thoughts and what is around you. In philosophy, the fact that there is something it is like to be you — and the open scientific question of why any physical process should feel like anything at all.
'The hard problem of consciousness' — David J. Chalmers, presented at the first Tucson conference in 1994 and published in 1995.
// Where it sits
After thirty years of dedicated science, this dial has not moved much.
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.
Where it comes from
Literally 'knowing-with'. The Latin root is social — awareness shared with another — before it turned inward in the 1630s.
Myths & misconceptions
Neuroscience has basically explained consciousness; the details are being filled in.
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.
The hard problem is just the easy problems, harder.
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?
Compare & contrast
Consciousness vs awareness
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.
| // | 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 |
How it connects
- Qualiathe name for the raw feels the hard problem is about.
- Aphantasiaa real, documented variation in inner experience — evidence that the inside differs between people.
Tell it apart
Questions people ask
- What 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.
- Did 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.
- Do 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.