Consciousness and its Place in Nature
David J. Chalmers
Department of Philosophy
University of Arizona
Tucson, AZ 85721.
chalmers@arizona.edu

Consciousness fits uneasily into our conception of the natural world. On the most common conception of nature, the natural world is the physical world. But on the most common conception of consciousness, it is not easy to see how it could be part of the physical world. So it seems that to find a place for consciousness within the natural order, we must either revise our conception of consciousness, or revise our conception of nature.

The word ‘consciousness’ is used in many different ways. It is sometimes used for the ability to
discriminate stimuli, or to report information, or to monitor internal states, or to control behavior.
We can think of these phenomena as posing the “easy problems” of consciousness. These are
important phenomena, and there is much that is not understood about them, but the problems of
explaining them have the character of puzzles rather than mysteries. There seems to be no deep
problem in principle with the idea that a physical system could be “conscious” in these senses,
and there is no obvious obstacle to an eventual explanation of these phenomena in
neurobiological or computational terms.
The hard problem of consciousness is the problem of experience. Humans beings have subjective
experience: there is something it is like to be them. We can say that a being is conscious in this
sense — or is phenomenally conscious, as it is sometimes put — when there is something it is
like to be that being. A mental state is conscious when there is something it is like to be in that
state. Conscious states include states of perceptual experience, bodily sensation, mental imagery,
emotional experience, occurrent thought, and more. There is something it is like to see a vivid
green, to feel a sharp pain, to visualize the Eiffel tower, to feel a deep regret, and to think that
one is late. Each of these states has a phenomenal character, with phenomenal properties (or
qualia) characterizing what it is like to be in the state.[]