Why are some things conscious and others apparently not? Is a rat conscious? A bat? A cockroach? A bacterium? An electron?
These questions are all aspects of the ancient “mind-body problem,” which has resisted a generally satisfying conclusion for thousands of years.
The mind-body problem enjoyed a major rebranding over the last two decades and is generally known now as the “hard problem” of consciousness (usually capitalized nowadays), after the New York University philosopher David Chalmers coined this term in a now classic 1995 paper and his 1996 book The Conscious Mind: In Search of a Fundamental Theory.