What is Consciousness and Can it be Defined?

Much is written on the Evolver website about consciousness. It seems every blog has a different take on what consciousness is and how it is defined. Some talk of "the spirit and enbodiment of planetary consciousness, the Great Mother Gaia." Others speak of our 'consensus consciousness' or 'eco-consciousness' or to put it in terms of our 2012 theme, "Humanity is currently undergoing a naturally horrifyfing transition from one state of consciusness to another." Some suggest that we are hardly conscious at all, going through life mechanically, predictably, imagining we are something we are not. As a teacher I know often says, "We imagine ourselves, really." One problem I see is that we do not share a definition of consciousness. We are subjective creatures and our paths are so diverse. To help begin our conversation, permit me to introduce a theory of the different states of consciousness. There are four states of consciousness available to humanity. They are 1) sleep, where we often enter the dream state, 2) relative consciousness, where we spent most of our time, only half awake, always forgetting, going through the mechanics of life, 3) self-consciousness, where we spent little of our time and includes such atributes as memory, self-awareness, self-observation, empathy, nonjudgmentalism and non attachment and 4) objective consciousness , which we know nothing about and can only be acquiired through much effort, help from our friends who have a common aim with the aid of higher forces. What say you?