[perl4ever]

I think "lack of consciousness" is not a well-defined concept. Popular forms of anesthesia these days result in what appears to be a more or less conscious patient in one sense, who can respond to some stimuli, but who does not form memories or feel pain. So in retropect, when the procedure is over, it's as if it never happened. But any observer can see they weren't unconscious as in dreamless sleep.

The point being, there are many components to what we call consciousness that seem to be demonstrably separable and it doesn't help to talk as though it's all just one unified whole.