The word “consciousness” is used in a variety of ways and has many different meanings so it will be necessary to analyze the different understandings of this word. Australian philosopher David Chalmers analyzes these different meanings:

“For example, one sometimes says that a mental state is conscious when it is verbally reportable, or when it is internally accessible. Sometimes a system is said to be conscious of some information when it has the ability to react on the basis of that information, or, more strongly, when it attends to that information, or when it can integrate that information and exploit it in the sophisticated control of behaviour. We sometimes say that an action is conscious precisely when it is deliberate. Often, we say that an organism is conscious as another way of saying that it is awake. There is no real issue whether these phenomena can be explained scientifically.” 1

Chalmers calls the study of any of these phenomena as “the easy problem of consciousness” because they can all be studied scientifically. Chalmers goes on to argue that there is another sense of the word “consciousness”: what it is like to be something, also called phenomenal consciousness 2. The study of this type of conscious experience is what Chalmers calls “the hard problem of consciousness.” The argument is that even if one were to fully understand consciousness from a neurobiological standpoint, then there is still more that one knows from actually experiencing consciousness firsthand. This something is the qualitative aspect of consciousness, called qualia. According to this theory, there are qualia associated with every kind of experience, such as color, pain, sweet taste, passion, etc.

1 Heil, John. Philosophy of Mind – A Guide and Anthology. New York: Oxford, 2004.

2 Chalmers, David. The Conscious Mind – In Search of a Fundamental Theory. New York: Oxford University Press, 1996.