At its most fundamental level, consciousness could be described as a sentient awareness of internal and external existence. As such, consciousness is something all humans apparently possess, but, strangely enough, our awareness of consciousness is rooted more in intuition than in measurable "fact".
Needless to say, this has inspired nothing but consternation among contemporary analytical philosophers of the mind, many of whom regard intuition as nothing more than an illusion - an illusion that inconveniently serves as an affront to their firmly held assumptions about the inherent meaninglessness of the universe.
I confess, consciousness as a proverbial thumb in the eye of meaninglessness is very appealing to me because it gets right to the root of what I believe consciousness addresses: metaphysical assumptions.
From this perspective, consciousness can be seen as the conduit through which the fundamental nature of reality can be approached, interpreted, and addressed. Moreover, it's existence helps or - from a more pessimistic perspective - hinders the framing of two basic and eternal metaphysical questions: What is there? What is it like?
For the sake of this post, I will limit the definition of human consciousness to the slightly epistemological definition of "how people think and understand".*
Dr. Bruce Charlton considers the question of how people think and understand what there is and what this "there" is like to be of monumental importance because it lays the groundwork upon which all subsequent empirical and theoretical evidence is weighed. "Such assumptions," Charlton notes, "come first, are deeper than 'evidence' (because evidence is itself structured by these assumptions)."
The beef many modern analytical philosophers of the mind have with consciousness is relatively straightforward and simple - the existence of consciousness challenges their metaphysical assumptions that everything in the universe is just stuff. Moreover, consciousness is an affront to the evidence they have structured upon these assumptions - evidence which posits that the "just stuff" is essentially meaningless.
What irks moderns about consciousness is its audacity to insist that the stuff means something; moreover, that this meaning is spiritual in nature. This intolerable audacity is often referred as the religious impulse, and it is this impulse of consciousness that most moderns find so appalling.
Simply put, within human consciousness exists the power to choose meaning over meaninglessness. Sadly, our current state of consciousness at the collective level slants heavily toward the latter.
Collectively we have all but abandoned the primacy of the spiritual in favor of the primacy of the material; in doing so, we have collectively favored the material at the expense of the spiritual. The detrimental consequences of this unprecedented change in human consciousness - a long, drawn out process spanning nearly three centuries - are everywhere apparent and becoming increasingly more so.
The further we pull away from the spiritual and bore into the material, the further we pull away from meaning and bore into meaninglessness.
The situation is becoming untenable. If human consciousness continues on its current course unabated, humanity will cast itself into a pit of meaninglessness. Once there, the mystery of human consciousness dissolve into nothingness.
Analyses of how people think and understand will be rendered obsolete because there will be nothing left to think about and nothing left to understand.
*I borrowed this simple but lucid definition from Kevin McCall's most recent post at No Longer Reading.