ABSTRACT
Although there is no recognised definition of consciousness, many researchers refer back to the famous question, ‘What is it like to be a bat?’ If there is anything it is like for the bat, that is what is meant by being conscious. This is also called ‘phenomenal consciousness’ (P-consciousness) or ‘phenomenality’ and is sometimes contrasted with ‘access consciousness’ (A-consciousness). Problems with this distinction are discussed. Philosophers refer to specific conscious experiences (like the colour red or the smell of coffee) as ‘qualia’, although this concept is also disputed. Some well-known thought experiments are used to illustrate these debates, including ‘Mary the colour scientist’ (who knows all the physical information about colour vision but has never left her black-and-white room) and the ‘Philosopher’s zombie’: a creature that is physically indistinguishable from a normal person but has no conscious experiences. This zombie is clearly conceivable, but is it possible? The many arguments about this are reviewed. We then return to the hard problem and possible responses to it: 1) The hard problem is insoluble, 2) We must try to solve it, 3) We should tackle the easy problems, 4) We should find more hard problems, and 5) There is no hard problem.
