"All of our conscious states, without exception, are caused by lower level neurobiological processes in the brain, and they are realized in the brain as higher level, or system features. It's about as mysterious as the liquidity of water, right? The liquidity is not an extra juice squirted out by the H2O molecules, it's a condition that the system is in; and just as the jar full of water can go from a liquid to solid, depending on the behavior of the molecules, so your brain can go from a state of being conscious to a state of being unconscious, depending on the behavior of the molecules. The famous mind body problem is that simple."