In reference to defining consciousness, I intended to add the dictionary definition, but they are mostly not-informative, relying on our inuitive understanding of consciousness and not really strictly defining the phenomenon. So, Wikipedia it is:http://en.wikipedia.org/wiki/Consciousness
Consciousness is the quality or state of being aware of an external object or something within oneself. It has been defined as: subjectivity, awareness, sentience, 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."
Philosophers since the time of Descartes and Locke have struggled to comprehend the nature of consciousness and pin down its essential properties. Issues of concern in the philosophy of consciousness include whether the concept is fundamentally valid; whether consciousness can ever be explained mechanistically; whether non-human consciousness exists and if so how it can be recognized; how consciousness relates to language; whether consciousness can be understood in a way that does not require a dualistic distinction between mental and physical states or properties; and whether it may ever be possible for computers or robots to be conscious.
At one time consciousness was viewed with skepticism by many scientists, but in recent years it has become a significant topic of research in psychology and neuroscience. The primary focus is on understanding what it means biologically and psychologically for information to be present in consciousness—that is, on determining the neural and psychological correlates of consciousness. The majority of experimental studies assess consciousness by asking human subjects for a verbal report of their experiences (e.g., "tell me if you notice anything when I do this"). Issues of interest include phenomena such as subliminal perception, blindsight, denial of impairment, and altered states of consciousness produced by psychoactive drugs or spiritual or meditative techniques.
One line I find interesting is "determining the neural and psychological correlates of consciousness". I appreciate that this phrase does not confuse correlation with causation, which is so common in discussions of consciousness. I have heard reports that they are getting fairly well tuned into a specific part of the brain which is responsible for bringing together information from all other parts of the brain and conglomerating it into a singular experience. While the correlation with consciousness is high in that case, it still does nothing to prove causation of consciousness (that consciousness is one and the same with this part of the brain).
On the other hand, all of the processes in neurology are large enough (physical dimension) that they would come under classical physical and chemistry laws (not a lot of quantum mechanical "weirdness"). Therefore, anything that interacts with the brain would have to either be of a known physical nature (mass, charge, etc), or interact via a new, undiscovered force, unless we posit a brand new mechanism for violating the central tenet of science (and Buddhism): causes have effects, effects have causes.
I do not have a horse in this race: both possibilities seem equally ridiculous to me. How could consciousness be purely physical? How could it be anything but physical? Both are absurd conclusions based on the currently available data. Again, this is why it's called "the hard problem".
Disciples, this I declare to you: All conditioned things are subject to disintegration – strive on untiringly for your liberation.
Sotthī hontu nirantaraṃ - May you forever be well.