Consciousness is the state or
quality of awareness, or, of being
aware of an external object or something within oneself. It has been defined as:
sentience,
awareness,
subjectivity, the ability to
experience or to
feel,
wakefulness, having a sense of
selfhood, and the executive control system of the mind. Despite the difficulty in definition, many philosophers believe that there is a broadly shared underlying intuition about what consciousness is. As
Max Velmans and Susan Schneider wrote in
The Blackwell Companion to Consciousness: "Anything that we are aware of at a given moment forms part of our consciousness, making conscious experience at once the most familiar and most mysterious aspect of our lives."