David J. Chalmers (born 1966) is an Australian philosopher, now at New York University, who works on the philosophy of mind and is best known for sharpening the question of consciousness into a form that has structured debate ever since. In his 1995 paper “Facing Up to the Problem of Consciousness,” self-archived on his website, he drew a line between what he called the easy problems and the hard problem.
The easy problems, in Chalmers’s framing, are the ones cognitive science is equipped to solve: explaining how the brain discriminates stimuli, integrates information, reports on its own states, controls behavior. These are “easy” only in the sense that we know what an explanation would look like - a mechanism. The hard problem is different: why is any of this information processing accompanied by subjective experience at all? Why is there something it is like to see red or hear a note, rather than the processing happening “in the dark”? No account of mechanism, he argued, seems to entail that experience must come along with it.
Chalmers has since become a prominent voice on whether artificial systems could be conscious, taking the question seriously rather than dismissing it, and arguing that nothing we know rules out machine consciousness in principle even as nothing we have built establishes it. He has also worked on the extended mind, virtual reality, and the foundations of AI.
For business and policy readers, Chalmers matters because his distinction explains why claims that an AI system is “sentient” are so hard to settle: behavior and self-report - the things we can measure - speak only to the easy problems, while the hard problem asks about an inner life that no external test can reach.